epic fail on test drive, need code help
Thread Starter
Safety Car
Joined: Dec 2011
Posts: 4,704
Likes: 239
From: Redondo Beach CA
epic fail on test drive, need code help
Well, maybe not epic, at least, it didn't go up in flames like a Viking funeral pyre, but I did have to pay for a cab ride home. Bummer after working on the car the better part of the day.
Here are the codes
10-pcm P0101 c
P0522 h c
p1120 h
p1220 h
p1431 h
p1514 h
p1516 h
p1635 h
Ipc b0521 h
U1064 h
u1160 h
Hvac b0361 h c
Ldcm b2264 h
Al-rdcm u1064 h
Rfa c2100 h c
c2105 h c
c2110 h c
c2115 h c
u1000 h
u1016 h
Here is the story
Took the manifold off about 45 days ago and just put it back together last Sunday. So the car had been sitting, but the battery was charged.
At the same time I did a little cleaning , with new plugs and wires, plus throttle body and air flow sensor cleaned. I think from now on I will only do one thing at a time, to better understand what the issues might be with an errant repair.
The repair goal was to relocate the oil sensor which had failed and had started to leak, smelling up the interior. The other stuff was just extra, while I had the car apart.
So anyway, I get the thing back together, and I am pleased when it starts. Then smoke started coming off of the right side where I put the plugs in. Seems I overdid it on the anti seize. So I let it run for a while, burning off the excess stuff , getting up to temperature, checking the work. Not my finest results, but after the smoke cleared, it seemed ok. No weird smells or other indicators of trouble.
One unresolved issue is that the oil pressure is reporting zero. Not pegged at the high end of the scale as before , but just as useless.
That will have to be re-done in the future, as the old wiring to the sender was damaged by leaking oil, and the pig tail replacement wires were not the same color code. I matched black to black , but the other two wires had no color match, and no old position to work from.
Other than that,eEverything seemed fine, so I decided to test drive the thing and get some Mexican food. I'm happy, the throttle response was improved, and I am taking the motor into higher rev's to check it out. I am staying with the speed limit, so only in first or second gear are needed.
I had about a third of a tank of gas when I started the shake down run.
Throttle response was a little uneven at first, just for a moment a couple of times , then it settled down. I assumed it was adjusting to the newly cleaned mass sensor and throttle body.
I'm out and it is a little late for a restaurant , so I decided on bar food. So I go a little further, by this time I am just cruising, the thing sucks gas at higher revs, but I feel I am ok and the gas gauge shows about what I expect. Except my gas gauge sometimes does the flop to empty, and the driver's warnings activate , under long steady state drives. So it has issues, perhaps it suffered with the non use.
I am driving along and the motor dies. Won't refire. Sounds like it will start, the normal deal, but it seems the fuel cuts off at the first ignition. I can hear the fuel pump pressuring the system, again and again as I try to start . I push it across the street into a converted gas station that is now a garage. Not the worst place, if you were choosing a break down spot. I don't know the car that well, but it sounds like it has an ignition circuit and then a run circuit, and as soon as one piston fires, the fuel in the run circuit stops.
First lesson I learned, don't test drive at night. Can't see what could be going on. Or not going on, in my case.
I decide to let the car cool, hopefully reset, or magically heal itself somehow, and walk back to the bars and eat. It's karaoke night, and it's at warp nine on the loudness scale. Lucky me.
After some food, still nothing happening with the car , so I leave a note and take a cab home from the bar. Yellow cab runs bunch of Toyota prius around town , and I was impressed. It was my first time in that model .
The next day I travel back to the car , before work, and the garage service writer says the car has got to be gone tonight or they will charge me 35 bucks storage. I get some passing Mormons to help me push it next door into the supermarket parking lot . They say over night is ok.
The garage where I first landed is not an option. I was next to some work as I screwed around with the codes. They were working on a big SUV and after the wheel came off, they couldn't figure out how to take apart and continue with whatever they were doing, I assume it was a break job. Strictly earn while you learn, at $120 dollars labor an hour.
I don't think it would be real productive to throw my car in there.
Tomorrow I will return to the car, hopefully with some new understanding of what has happened
Here are the codes
10-pcm P0101 c
P0522 h c
p1120 h
p1220 h
p1431 h
p1514 h
p1516 h
p1635 h
Ipc b0521 h
U1064 h
u1160 h
Hvac b0361 h c
Ldcm b2264 h
Al-rdcm u1064 h
Rfa c2100 h c
c2105 h c
c2110 h c
c2115 h c
u1000 h
u1016 h
Here is the story
Took the manifold off about 45 days ago and just put it back together last Sunday. So the car had been sitting, but the battery was charged.
At the same time I did a little cleaning , with new plugs and wires, plus throttle body and air flow sensor cleaned. I think from now on I will only do one thing at a time, to better understand what the issues might be with an errant repair.
The repair goal was to relocate the oil sensor which had failed and had started to leak, smelling up the interior. The other stuff was just extra, while I had the car apart.
So anyway, I get the thing back together, and I am pleased when it starts. Then smoke started coming off of the right side where I put the plugs in. Seems I overdid it on the anti seize. So I let it run for a while, burning off the excess stuff , getting up to temperature, checking the work. Not my finest results, but after the smoke cleared, it seemed ok. No weird smells or other indicators of trouble.
One unresolved issue is that the oil pressure is reporting zero. Not pegged at the high end of the scale as before , but just as useless.
That will have to be re-done in the future, as the old wiring to the sender was damaged by leaking oil, and the pig tail replacement wires were not the same color code. I matched black to black , but the other two wires had no color match, and no old position to work from.
Other than that,eEverything seemed fine, so I decided to test drive the thing and get some Mexican food. I'm happy, the throttle response was improved, and I am taking the motor into higher rev's to check it out. I am staying with the speed limit, so only in first or second gear are needed.
I had about a third of a tank of gas when I started the shake down run.
Throttle response was a little uneven at first, just for a moment a couple of times , then it settled down. I assumed it was adjusting to the newly cleaned mass sensor and throttle body.
I'm out and it is a little late for a restaurant , so I decided on bar food. So I go a little further, by this time I am just cruising, the thing sucks gas at higher revs, but I feel I am ok and the gas gauge shows about what I expect. Except my gas gauge sometimes does the flop to empty, and the driver's warnings activate , under long steady state drives. So it has issues, perhaps it suffered with the non use.
I am driving along and the motor dies. Won't refire. Sounds like it will start, the normal deal, but it seems the fuel cuts off at the first ignition. I can hear the fuel pump pressuring the system, again and again as I try to start . I push it across the street into a converted gas station that is now a garage. Not the worst place, if you were choosing a break down spot. I don't know the car that well, but it sounds like it has an ignition circuit and then a run circuit, and as soon as one piston fires, the fuel in the run circuit stops.
First lesson I learned, don't test drive at night. Can't see what could be going on. Or not going on, in my case.
I decide to let the car cool, hopefully reset, or magically heal itself somehow, and walk back to the bars and eat. It's karaoke night, and it's at warp nine on the loudness scale. Lucky me.
After some food, still nothing happening with the car , so I leave a note and take a cab home from the bar. Yellow cab runs bunch of Toyota prius around town , and I was impressed. It was my first time in that model .
The next day I travel back to the car , before work, and the garage service writer says the car has got to be gone tonight or they will charge me 35 bucks storage. I get some passing Mormons to help me push it next door into the supermarket parking lot . They say over night is ok.
The garage where I first landed is not an option. I was next to some work as I screwed around with the codes. They were working on a big SUV and after the wheel came off, they couldn't figure out how to take apart and continue with whatever they were doing, I assume it was a break job. Strictly earn while you learn, at $120 dollars labor an hour.
I don't think it would be real productive to throw my car in there.
Tomorrow I will return to the car, hopefully with some new understanding of what has happened
Tech Contributor
Joined: Aug 1999
Posts: 16,376
Likes: 404
From: Should this thoughtful, valuable contribution meet with no acknowledgement or 'thanks' this post----
sounds awful...I think it needs to go to a vette tuner...someone with a dyno. bad joke, but you should change your avatar to Stranded rider now...
sorry...
in the end it will all work out when a pro gets into it.
sorry... in the end it will all work out when a pro gets into it.
Thread Starter
Safety Car
Joined: Dec 2011
Posts: 4,704
Likes: 239
From: Redondo Beach CA
Could you give me a little more info on the code you mentioned? What it represents exactly, if possible. I used a dedicated spray can cleaner on the mafs, perhaps I damaged it at that time.
I ask for more detail because of the non returnable expense that comes with that part. It will cost me about $100 to get the car to the only corvette shop I know of . That part is pretty easy to get to, easy to replace hard to understand.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Thank you for the reply. I was guessing that the none historic codes were the problem indicator, but have no understanding what they mean. Your reply is greatly appreciated.
Could you give me a little more info on the code you mentioned? What it represents exactly, if possible. I used a dedicated spray can cleaner on the mafs, perhaps I damaged it at that time.
Could you give me a little more info on the code you mentioned? What it represents exactly, if possible. I used a dedicated spray can cleaner on the mafs, perhaps I damaged it at that time.
http://www.stengel.net/diccodes.htm
The wording of that code is pretty vague. I can look in my service manual later tonight and see if there's more detail.
I would start by checking all the wiring for both the MAFS and throttle butterfly. Make sure everything is clean and tight.
Last edited by wcsinx; Jun 4, 2013 at 03:28 PM.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Document ID# 795634
2002 Chevrolet Corvette
DTC P0101
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal in order to provide the correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF sensor has an ignition 1 voltage circuit, a ground circuit and a signal circuit. The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage in order to produce a frequency based on inlet air flow through the sensor bore. The frequency varies within a range of around 2,000 Hertz at idle to about 11,500 Hertz at maximum engine load. The PCM uses the following sensor inputs in order to calculate a predicted MAF value:
The manifold absolute pressure (MAP)
The intake air temperature (IAT)
The engine coolant temperature (ECT)
The engine speed (RPM)
The PCM compares the actual MAF sensor frequency signal to the predicted MAF value. This comparison will determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC P0101 sets if the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value.
Conditions for Running the DTC
DTCs P0102, P0103, P0107, P0108, P0112, P0113, P1120, P1220, and P1221 are not set.
The engine is running.
The ignition 1 signal is between 11-18 volts.
The throttle position (TP) indicated angle is less than 95 percent.
The change in the TP indicated angle is less than 5 percent.
The MAP sensor is more than 17 kPa.
The change in the MAP sensor is less than 3 kPa.
The above conditions are met for 1.5 seconds.
Conditions for Setting the DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 0.5 second.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Inspect for the following conditions:
An incorrectly routed harness. Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
The secondary ignition wires or coils
Any solenoids
Any relays
Any motors
Any excessive deposits on the throttle plate or in the throttle bore.
A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
A wide open throttle acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 4-7 g/s at idle to 190 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
The barometric pressure that is used in order to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
Any loss of vacuum to the MAP sensor can cause this DTC to set.
If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Wiring Systems.
If the condition is intermittent, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step will determine if the MAP sensor voltage is within the proper range at idle.
This step will determine if the MAP sensor responds properly to the change in manifold pressure.
This step will determine if the throttle position (TP) sensor is operating properly.
This step will determine if any mechanical faults have caused this DTC to set.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls ?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start the engine.
Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the scan tool display any other DTCs set?
--
Go to Diagnostic Trouble Code (DTC) List
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Allow the engine to reach operating temperature.
Observe the MAP sensor voltage with a scan tool .
Is the MAP sensor voltage within the specified range?
0.8-4 V
Go to Step 5
Go to DTC P0106
5
Idle the engine.
Observe the MAP sensor kPa with a scan tool.
Increase the engine speed slowly to 3,000 RPM and then back to idle.
Does the MAP sensor kPa change smoothly and gradually through the specified range of the test?
--
Go to Step 6
Go to DTC P0106
6
Important:
If the vehicle is equipped with throttle actuator control (TAC), proceed to the next step.
Turn OFF the ignition.
Turn ON the ignition, with the engine OFF.
Observe the TP sensor angle from closed throttle to wide open throttle.
Depress completely and then release the accelerator pedal.
Does the scan tool indicate that the TP sensor angle changed smoothly and completely through the specified range of the test?
--
Go to Step 7
--
7
Inspect for the following conditions:
A restricted air intake duct
A collapsed air intake duct
A misaligned air intake duct
A dirty air filter element
A deteriorating air filter element
Any objects blocking the air inlet screen of the MAF sensor
Any debris on the sensing elements of the MAF sensor
Any vacuum leak downstream of the MAF sensor
A poor vacuum connection at the MAP sensor
A restricted exhaust system
Did you find and correct the condition?
--
Go to Step 10
Go to Step 8
8
Test for an intermittent and for a poor connection at the MAF/IAT sensor. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 10
Go to Step 9
9
Replace the MAF/IAT sensor. Refer to Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement
Did you complete the replacement?
--
Go to Step 10
--
10
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 11
Go to Step 2
11
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
Document ID# 795634
2002 Chevrolet Corvette
2002 Chevrolet Corvette
DTC P0101
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The powertrain control module (PCM) uses the MAF sensor signal in order to provide the correct fuel delivery for a wide range of engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle. A large quantity of air entering the engine indicates an acceleration or high load condition. The MAF sensor has an ignition 1 voltage circuit, a ground circuit and a signal circuit. The PCM applies a voltage to the sensor on the signal circuit. The sensor uses the voltage in order to produce a frequency based on inlet air flow through the sensor bore. The frequency varies within a range of around 2,000 Hertz at idle to about 11,500 Hertz at maximum engine load. The PCM uses the following sensor inputs in order to calculate a predicted MAF value:
The manifold absolute pressure (MAP)
The intake air temperature (IAT)
The engine coolant temperature (ECT)
The engine speed (RPM)
The PCM compares the actual MAF sensor frequency signal to the predicted MAF value. This comparison will determine if the signal is stuck based on a lack of variation, or is too low or too high for a given operating condition. DTC P0101 sets if the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value.
Conditions for Running the DTC
DTCs P0102, P0103, P0107, P0108, P0112, P0113, P1120, P1220, and P1221 are not set.
The engine is running.
The ignition 1 signal is between 11-18 volts.
The throttle position (TP) indicated angle is less than 95 percent.
The change in the TP indicated angle is less than 5 percent.
The MAP sensor is more than 17 kPa.
The change in the MAP sensor is less than 3 kPa.
The above conditions are met for 1.5 seconds.
Conditions for Setting the DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 0.5 second.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
Inspect for the following conditions:
An incorrectly routed harness. Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
The secondary ignition wires or coils
Any solenoids
Any relays
Any motors
Any excessive deposits on the throttle plate or in the throttle bore.
A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
A wide open throttle acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 4-7 g/s at idle to 190 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
The barometric pressure that is used in order to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
Any loss of vacuum to the MAP sensor can cause this DTC to set.
If you suspect the condition may be related to aftermarket accessories, refer to Checking Aftermarket Accessories in Wiring Systems.
If the condition is intermittent, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step will determine if the MAP sensor voltage is within the proper range at idle.
This step will determine if the MAP sensor responds properly to the change in manifold pressure.
This step will determine if the throttle position (TP) sensor is operating properly.
This step will determine if any mechanical faults have caused this DTC to set.
Step
Action
Values
Yes
No
Schematic Reference: Engine Controls Schematics
1
Did you perform the Diagnostic System Check-Engine Controls ?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls
2
Start the engine.
Monitor the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the scan tool display any other DTCs set?
--
Go to Diagnostic Trouble Code (DTC) List
Go to Step 3
3
Observe the Freeze Frame/Failure Records data for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.
Does the DTC fail this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Allow the engine to reach operating temperature.
Observe the MAP sensor voltage with a scan tool .
Is the MAP sensor voltage within the specified range?
0.8-4 V
Go to Step 5
Go to DTC P0106
5
Idle the engine.
Observe the MAP sensor kPa with a scan tool.
Increase the engine speed slowly to 3,000 RPM and then back to idle.
Does the MAP sensor kPa change smoothly and gradually through the specified range of the test?
--
Go to Step 6
Go to DTC P0106
6
Important:
If the vehicle is equipped with throttle actuator control (TAC), proceed to the next step.
Turn OFF the ignition.
Turn ON the ignition, with the engine OFF.
Observe the TP sensor angle from closed throttle to wide open throttle.
Depress completely and then release the accelerator pedal.
Does the scan tool indicate that the TP sensor angle changed smoothly and completely through the specified range of the test?
--
Go to Step 7
--
7
Inspect for the following conditions:
A restricted air intake duct
A collapsed air intake duct
A misaligned air intake duct
A dirty air filter element
A deteriorating air filter element
Any objects blocking the air inlet screen of the MAF sensor
Any debris on the sensing elements of the MAF sensor
Any vacuum leak downstream of the MAF sensor
A poor vacuum connection at the MAP sensor
A restricted exhaust system
Did you find and correct the condition?
--
Go to Step 10
Go to Step 8
8
Test for an intermittent and for a poor connection at the MAF/IAT sensor. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 10
Go to Step 9
9
Replace the MAF/IAT sensor. Refer to Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Replacement
Did you complete the replacement?
--
Go to Step 10
--
10
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 11
Go to Step 2
11
With a scan tool, observe the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK
Document ID# 795634
2002 Chevrolet Corvette
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Document ID# 1489128
2002 Chevrolet Corvette
Service VME - 4.8 5.3 6.0 LM4 LM7 LR4 LQ4 LQ9 GEN III Engines with MAF Sensor Code P0101 - kw driveability fluctuation idle intermittent MAP rough stall surge hesitation #PI01624A - (Apr 5, 2004)
Service VME - 4.8 5.3 6.0 LM4 LM7 LR4 LQ4 LQ9 GEN III Engines with MAF Sensor Code P0101
.
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
SERVICE VME
This message applies to all 1999 through 2004 Chevrolet, GMC, Olds, Buick and Cadillac pick-ups and utilities that are equipped with either the 4.8 liter, 5.3 liter or 6.0 liter Gen 3 V-8 engines. Recent warranty analysis indicates that both the MAF, or mass airflow sensor, and the MAP, or manifold absolute pressure sensor, are being replaced for a MAF sensor code P0101. The cause may actually be a MAP sensor failure causing the MAF sensor code. One of the MAP sensor[rsquo ]s primary functions is the calculation of the speed density formula, which is compared to the MAF sensor reading. Should the MAP sensor fail, the PCM may interpret this as a MAF sensor concern and set a P0101 code. If diagnostics are followed thoroughly the technician may find a MAP sensor failure causing this condition. In conclusion, when a MAF sensor code of P0101 is found the technician needs to verify the proper operation of the MAP sensor before concluding that the MAF sensor requires replacement.
.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
.
MODELS:
(00-04 Chevrolet Silverado Truck C1,C2,C3) and (00-04 Chevrolet Tahoe C1,C2,C3) and (00-04 Chevrolet Suburban C1,C2,C3) and (00-04 GMC Sierra Truck C1,C2,C3) and (00-04 GMC Yukon C1, C2, C3) and (00-04 GMC Yukon XL C1, C2 C3) and (02-04 Cadillac, Escalade, C6) and (03-04 Cadillac, EXT, C1) and (02-043 Chevrolet, Avalanche, K1, K2) and (02-04 Chevrolet Silverado Truck K1, K2, K3) and (02-04 GMC Sierra Truck K1, K2, K3) and (02-04 Chevrolet Tahoe, K1, K2, K3) and (02- 04 Chevrolet Suburban, K1, K2, K3) and (03 Chevrolet Camaro) and (02-04 Chevrolet Corvette) and (03 Pontiac Firebird) and (02-04 GMC, Yukon, K1, K2, K3) and (02-04 GMC, Yukon XL, C1,C2, C3) and (00-04 GMC, Yukon XL, K1, K2, K3) and (03-04 GMC S1 T1) and (03-04 Chevrolet S1 T1) and (03-04 Chevrolet Express G1, G2) and (03-04 GMC Savana G1, G2)
.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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Document ID# 1489128
2002 Chevrolet Corvette
2002 Chevrolet Corvette
Service VME - 4.8 5.3 6.0 LM4 LM7 LR4 LQ4 LQ9 GEN III Engines with MAF Sensor Code P0101 - kw driveability fluctuation idle intermittent MAP rough stall surge hesitation #PI01624A - (Apr 5, 2004)
Service VME - 4.8 5.3 6.0 LM4 LM7 LR4 LQ4 LQ9 GEN III Engines with MAF Sensor Code P0101
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When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
SERVICE VME
This message applies to all 1999 through 2004 Chevrolet, GMC, Olds, Buick and Cadillac pick-ups and utilities that are equipped with either the 4.8 liter, 5.3 liter or 6.0 liter Gen 3 V-8 engines. Recent warranty analysis indicates that both the MAF, or mass airflow sensor, and the MAP, or manifold absolute pressure sensor, are being replaced for a MAF sensor code P0101. The cause may actually be a MAP sensor failure causing the MAF sensor code. One of the MAP sensor[rsquo ]s primary functions is the calculation of the speed density formula, which is compared to the MAF sensor reading. Should the MAP sensor fail, the PCM may interpret this as a MAF sensor concern and set a P0101 code. If diagnostics are followed thoroughly the technician may find a MAP sensor failure causing this condition. In conclusion, when a MAF sensor code of P0101 is found the technician needs to verify the proper operation of the MAP sensor before concluding that the MAF sensor requires replacement.
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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
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(00-04 Chevrolet Silverado Truck C1,C2,C3) and (00-04 Chevrolet Tahoe C1,C2,C3) and (00-04 Chevrolet Suburban C1,C2,C3) and (00-04 GMC Sierra Truck C1,C2,C3) and (00-04 GMC Yukon C1, C2, C3) and (00-04 GMC Yukon XL C1, C2 C3) and (02-04 Cadillac, Escalade, C6) and (03-04 Cadillac, EXT, C1) and (02-043 Chevrolet, Avalanche, K1, K2) and (02-04 Chevrolet Silverado Truck K1, K2, K3) and (02-04 GMC Sierra Truck K1, K2, K3) and (02-04 Chevrolet Tahoe, K1, K2, K3) and (02- 04 Chevrolet Suburban, K1, K2, K3) and (03 Chevrolet Camaro) and (02-04 Chevrolet Corvette) and (03 Pontiac Firebird) and (02-04 GMC, Yukon, K1, K2, K3) and (02-04 GMC, Yukon XL, C1,C2, C3) and (00-04 GMC, Yukon XL, K1, K2, K3) and (03-04 GMC S1 T1) and (03-04 Chevrolet S1 T1) and (03-04 Chevrolet Express G1, G2) and (03-04 GMC Savana G1, G2)
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Document ID# 1489128
2002 Chevrolet Corvette
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Worth a try.
Thread Starter
Safety Car
Joined: Dec 2011
Posts: 4,704
Likes: 239
From: Redondo Beach CA
Bike riding been berry berry good to me
Stranded rider here. It is true I've been squeekin shoe leather all over town since I got the vette.
Given time to consider the first answer to my question, I feared I had asked for too much. I had already received the answer that let me smell the stink my mechanical skills had cooked up. I didn't want to appear that I didn't understand, and regretted my unconsidered follow up question.
And now I get a reply with all the info right out of the book. I love that stuff. Why, because I don't like the feeling when I screw things up. Knowledge is power, I always repeat. Someone else said it.
Anyway, To quote, I don't think my "signal is within the predetermined range". If I was thinking, or had deeper experience , I would have returned to base when I got the uneven throttle response, even when it cleared up. I should have realized I was on borrowed time, something was up, and it wasn't my mechanical IQ.
But, fun loving optimist that I am , I was thinking that these new fangled electronically controlled cars have "fuzzy logic" and it was only correcting for the newly cleaned sensor, since the condition seemed odd, but slight , and then went away.
What I think happened is that the start circuit is intact on the sensor, and I destroyed the run circuit when I cleaned the thing. It might have hung on for a while but the circuit lost it on the drive.
That would explain why the-start normally, but only for an instant, it never really catches fire, deal is playing out.
I don't think it is out of fuel, I was running a lot of throttle and that could clear a tank in a hurry, but I feel I should be ok . I took it pretty easy once I thought the car was running , "normaly". Plus, I can hear the fuel pump shut off after I turn the key on , and the fuel pressure comes up, after the car had failed to start. Unless it is on a timer, there has to be gas to shut off the pump.
Still Not a bad idea to throw in some juice. I will also check for stray electrical fields around the wires, I hadn't thought of that , but a wire loom that old pretty much wants be where it is used to being in place.
Given the help I received, I have decided to flat bed it home. I feel comfortable making that decision , through the insight gained here.
I would feel pretty dang dumb towing the thing home, and then towing it out again after failed repair attempts. I felt dumb driving it out, and then, now towing it home.
I don't have a scan tool, but I might have access to one, but even so it seems pretty hard to do air flow voltage comparisons when the engine won't start.
I have a perfect memory, it is just slow. I remembered reading a magazine article about cleaning MAFS, don't get too close with the spray, the sensors are extremely delicate. I remembered that little item after I had emptied a can of cleaner on the thing. It looked ok.
I am glad I now have some tools to know if the handwriting on the wall says what I think it might.
I did a little checking about the possible cost of my error. It seems mid America Motor works sells a new "modified " sensor as part of a performance package for one hundred dollars over what a stock sensor will cost, at quick glance. It also contains a smooth air coupler, never really liked the stock bellows, and a couple of K and N cone filters on a "Y " air intake.
Not really concerned that this area needs a redesign. But it is something to think about, if I am , in fact, in the market for a MAFS. I already have the other half of Mid America's suggested equation, a free flow exhaust, in my case a magniflow axle back muffler.
Not a bad deal, and I think one would need a complete air flow redesign, to effect any real performance change. I don't think the engine would be that impressed with just a smooth coupler. And that coupler is the only part that really grabs me.
Still it might be cool. Drawbacks, unknown parts brand, and more power = more gas. And, a lot of the redesign stuff I see trades torque for horsepower, since more horsepower sounds pretty good fr sales.
I would think the original engineers would have optimized the design. At least enough to make it hard to improve on one area without effecting another.
Mid America pitches this kit without any promises, they seem like good people when I met a few employees. They pitch, " maximum airflow equals ultimate engine performance", well, dah. And the final pitch, you save $150 bucks with the kit. In another area of mid america's catalog, they sell the same air system, plus and an "X" pipe and an axle back exhaust. With that package, they do make a few statements, better fuel milage, and "up to" 25 hp and 30lb torque. Now that sounds like an upgrade worth a hundred fun tickets over just a sensor.
I might go for it. It depends on price. At the same corvette event where I met the mid America reps, the restoration experts recommended only GM parts, if cost is not an objection. And the stock plastic air stuff is light.
Please advise if you see any flaws in my understanding , or approach to the situation.
tonight the car still sits at Vons parking lot. The manager gave me one more night, and I wanted as much information as possible before I called for a tow. The bright side is that I am not paying that chap *** manager next door at the garage 35 bucks to park it there.
I assume the car was desperate to get off the jack stands and finally out of the back yard. Gave it a good try but called it quits when it saw the repair shop across the street. ( the story in children's story book form) or perhaps it just smelled money and wanted to pull in.
Given time to consider the first answer to my question, I feared I had asked for too much. I had already received the answer that let me smell the stink my mechanical skills had cooked up. I didn't want to appear that I didn't understand, and regretted my unconsidered follow up question.
And now I get a reply with all the info right out of the book. I love that stuff. Why, because I don't like the feeling when I screw things up. Knowledge is power, I always repeat. Someone else said it.
Anyway, To quote, I don't think my "signal is within the predetermined range". If I was thinking, or had deeper experience , I would have returned to base when I got the uneven throttle response, even when it cleared up. I should have realized I was on borrowed time, something was up, and it wasn't my mechanical IQ.
But, fun loving optimist that I am , I was thinking that these new fangled electronically controlled cars have "fuzzy logic" and it was only correcting for the newly cleaned sensor, since the condition seemed odd, but slight , and then went away.
What I think happened is that the start circuit is intact on the sensor, and I destroyed the run circuit when I cleaned the thing. It might have hung on for a while but the circuit lost it on the drive.
That would explain why the-start normally, but only for an instant, it never really catches fire, deal is playing out.
I don't think it is out of fuel, I was running a lot of throttle and that could clear a tank in a hurry, but I feel I should be ok . I took it pretty easy once I thought the car was running , "normaly". Plus, I can hear the fuel pump shut off after I turn the key on , and the fuel pressure comes up, after the car had failed to start. Unless it is on a timer, there has to be gas to shut off the pump.
Still Not a bad idea to throw in some juice. I will also check for stray electrical fields around the wires, I hadn't thought of that , but a wire loom that old pretty much wants be where it is used to being in place.
Given the help I received, I have decided to flat bed it home. I feel comfortable making that decision , through the insight gained here.
I would feel pretty dang dumb towing the thing home, and then towing it out again after failed repair attempts. I felt dumb driving it out, and then, now towing it home.
I don't have a scan tool, but I might have access to one, but even so it seems pretty hard to do air flow voltage comparisons when the engine won't start.
I have a perfect memory, it is just slow. I remembered reading a magazine article about cleaning MAFS, don't get too close with the spray, the sensors are extremely delicate. I remembered that little item after I had emptied a can of cleaner on the thing. It looked ok.
I am glad I now have some tools to know if the handwriting on the wall says what I think it might.
I did a little checking about the possible cost of my error. It seems mid America Motor works sells a new "modified " sensor as part of a performance package for one hundred dollars over what a stock sensor will cost, at quick glance. It also contains a smooth air coupler, never really liked the stock bellows, and a couple of K and N cone filters on a "Y " air intake.
Not really concerned that this area needs a redesign. But it is something to think about, if I am , in fact, in the market for a MAFS. I already have the other half of Mid America's suggested equation, a free flow exhaust, in my case a magniflow axle back muffler.
Not a bad deal, and I think one would need a complete air flow redesign, to effect any real performance change. I don't think the engine would be that impressed with just a smooth coupler. And that coupler is the only part that really grabs me.
Still it might be cool. Drawbacks, unknown parts brand, and more power = more gas. And, a lot of the redesign stuff I see trades torque for horsepower, since more horsepower sounds pretty good fr sales.
I would think the original engineers would have optimized the design. At least enough to make it hard to improve on one area without effecting another.
Mid America pitches this kit without any promises, they seem like good people when I met a few employees. They pitch, " maximum airflow equals ultimate engine performance", well, dah. And the final pitch, you save $150 bucks with the kit. In another area of mid america's catalog, they sell the same air system, plus and an "X" pipe and an axle back exhaust. With that package, they do make a few statements, better fuel milage, and "up to" 25 hp and 30lb torque. Now that sounds like an upgrade worth a hundred fun tickets over just a sensor.
I might go for it. It depends on price. At the same corvette event where I met the mid America reps, the restoration experts recommended only GM parts, if cost is not an objection. And the stock plastic air stuff is light.
Please advise if you see any flaws in my understanding , or approach to the situation.
tonight the car still sits at Vons parking lot. The manager gave me one more night, and I wanted as much information as possible before I called for a tow. The bright side is that I am not paying that chap *** manager next door at the garage 35 bucks to park it there.
I assume the car was desperate to get off the jack stands and finally out of the back yard. Gave it a good try but called it quits when it saw the repair shop across the street. ( the story in children's story book form) or perhaps it just smelled money and wanted to pull in.
Thread Starter
Safety Car
Joined: Dec 2011
Posts: 4,704
Likes: 239
From: Redondo Beach CA
thanks again to all for the input.
I think I will start over again, take it apart and reassemble , this time paying attention to the newly installed oil sensor wire. I still have to figure out the order of the wires, as the two wires that are not black were disconnected.
I flat bedded it home and found the battery much flatter than it was the previous day. It cranked very slowly, almost dead. The day before it was still cranking strong. Unless someone was messing around in my absence, I might have an electrical leak.
I think I will start over again, take it apart and reassemble , this time paying attention to the newly installed oil sensor wire. I still have to figure out the order of the wires, as the two wires that are not black were disconnected.
I flat bedded it home and found the battery much flatter than it was the previous day. It cranked very slowly, almost dead. The day before it was still cranking strong. Unless someone was messing around in my absence, I might have an electrical leak.
Thread Starter
Safety Car
Joined: Dec 2011
Posts: 4,704
Likes: 239
From: Redondo Beach CA
thanks again to all for the input.
I think I will start over again, take it apart and reassemble , this time paying attention to the newly installed oil sensor wire. I still have to figure out the order of the wires, as the two wires that are not black were disconnected.
I flat bedded it home and found the battery much flatter than it was the previous day. It cranked very slowly, almost dead. The day before it was still cranking strong. Unless someone was messing around in my absence, I might have an electrical leak.
I will also clear the codes and read again. I was unsure about that until I posted for help. I didn't want to loose needed info , and feared loosing some critical repair indicator. Now I know.
I think I will start over again, take it apart and reassemble , this time paying attention to the newly installed oil sensor wire. I still have to figure out the order of the wires, as the two wires that are not black were disconnected.
I flat bedded it home and found the battery much flatter than it was the previous day. It cranked very slowly, almost dead. The day before it was still cranking strong. Unless someone was messing around in my absence, I might have an electrical leak.
I will also clear the codes and read again. I was unsure about that until I posted for help. I didn't want to loose needed info , and feared loosing some critical repair indicator. Now I know.
Last edited by strand rider; Jun 6, 2013 at 03:30 PM.