My car has been at the dealer for over a month. My car started shutting off on me going down the highway, throwing the code for the mass air flow sensor. Autozone was just down the road so I went and purchased one. Still throwing the same code.

I decided I would just to take the car to the dealer. They kept it for a day and told me it was still throwing the code because the MAF was not made by GM. So I purchased one from them for $385 carried it home and put it on. Still throwing the same code.

Took the car back to the dealer, then they said the PCM was faulty and needed to be rebuilt. They said neither new or used ones were available and the only option was to take it to Autozone and let them send it off to be rebuilt. A couple of weeks later they get it back from Autozone but they said it was not able to be rebuilt. They said my only option was to find one out of a wrecked 1997 vette. They said it had to be a 1997 no other model year would work. Is this correct?

Do I have any other options? I know there was not a lot of vettes made in 1997.

 

I am having a similar problem right now, it started with two bad wires to the Throttle Position Sensor and when tracking that problem down I ended up doing something causing the MAF to act up,
my car now runs good at idle and WOT but rough at highway speed.

I am sure I have another bad wire because when testing voltage on the plug with the ignition on one wire should have 12volts the other 5 volts I have 5 on the one but the one with 12 has nothing.

I have been researching and found a fuse could be blown causing the problem.
I did jump a hot 12 volt wire to mine but it did not help so I have more problems.
If yours is the 3 wire plug get a voltmeter and check the voltage of the plug with the ignition on but not running
Center is ground, Pink I think is the 12 volt the yellow is 5 volt
if no 12 volt is detected
Check under-hood fuse #17
if all else is good
Check for vacuum leaks and PCV system.

I was told the MAF could be turned off with a tune which is what I am looking at doing if all else fails.

 

Hey folks, the 97 and 98 model year Vettes have very unique are inductions systems.
Can you please post up any mods on the motor and the fault codes?

FYI Info

Air intake system draws outside air through the louvered cover and filter element of the forward mounted air cleaner. The air cleaner assembly is remotely mounted. The air is then ducted to the MAF sensor and then past the IAT sensor into the throttle body to the intake manifold. The air is then directed into the intake manifold runners, through cylinder heads and into the cylinders.
If the Mass Air Flow (MAF) sensor is installed backwards, the system will go rich. An arrow cast into the plastic portion of the sensor indicates proper air flow direction. The arrow must point toward the engine.
The fuel pressure regulator is a diaphragm operated relief valve with fuel pump pressure on one side and regulator spring pressure on the other side. The fuel pressure regulator is vented to atmosphere (in the intake or air bridge). A software bias is used to compensate injector on-time because the regulator is not referenced to manifold vacuum. The injector pulse width varies with the signal from the MAP sensor. With the ignition ON and the engine OFF, system fuel pressure at the pressure test connection should read 380-420 kPa (55-61 psi). If the pressure is too low, poor performance could result. If the pressure is too high, excessive odor and a Diagnostic Trouble Code (DTC) P0132, P0152, P0172 or P0175 may result. The Fuel System Diagnosis table has information on diagnosing fuel pressure conditions.

Circuit Description
The Mass Air Flow (MAF) sensor measures the amount of air ingested by the engine. The direct measurement of the air entering the engine is more accurate than calculating the airflow from the MAP, the IAT and the engine speed (speed/density). The MAF sensor has a battery feed, ground, and a signal circuit.

The MAF sensor used on this engine is a hot wire type. This engine uses the MAF sensor to measure air flow rate. The MAF output frequency is a function of the power required to keep the air flow sensing elements (hot wires) at a fixed temperature above the ambient temperature. Air flowing through the sensor cools the sensing elements. The amount of cooling is proportional to the amount of air flow. As the air flow increases, the MAF sensor requires a greater amount of current in order to maintain the hot wires at a constant temperature. The MAF sensor converts the changes in current draw to a frequency signal read by the PCM. The PCM calculates the air flow (grams per second) based on this signal.

The PCM monitors the MAF sensor frequency. The PCM can determine if the sensor is stuck low, stuck high, not providing the airflow value expected for a given operating condition, or that the signal appears to be stuck based on a lack of signal variation expected during the normal operation. This diagnostic checks the range/performance of the MAF sensor. The MAF system performance or rationality diagnostic uses the MAP, the IAT, and the engine speed to calculate an expected airflow rate. The PCM then compares the rate to the actual measured airflow from the MAF sensor. The PCM only compares the actual MAF value and the calculated value during conditions where the values are likely to match. If the actual MAF reading is not within a predetermined range of the calculated reading, a DTC will set.

Goose

 

My car is stuck at the dealer ship waiting on me to find a PCM. Thats what this thread is about. I do not remember the codes. But since the PCM was sent off to be rebuilt and returned as non repairable, I'm not really concerned about checking the MAF at this point.

Is the PCM the same for the 1997 and 1998 models?

 

Mine has several bolt on mods.
Vararam
Ported polished Throttle body,
LS6 intake
Custom tune (2 years ago)
long tube headers
no cats straight pipe back to quad tip Borla mufflers
O2 deleted
Air system removed and turned off in tune.
High volume oil pump
More I just can not think at the moment


It was running fine till driving at highway speed and all at onec it started sputtering and reduced engine power popped up. The Throttle position sensor codes came on along with the p0102 mass air flow.
I tried everything and traced wires found a couple vacuum lines that were dry rotted
I replaced them but no doubt I have more i knocked loose I have yet to find.

I removed the PCM/TAC to check the harness and wires.
At the moment the PCM/TAC are sitting in the battery compartment I have not mounted them back yet waiting till I trace down the problem.

I traced the Throttle sensor to 2 wires that were broken 4 inches back from the plug.
When they were fixed the reduced engine power went away along with the codes associated with the Throttle sensor.
It now starts and runs good at idle and WOT but is rough at highway speed
Checking the plug I have good ground and 5volts to one wire but no voltage to the one that is supposed to have 12 volts.
Unplugging it while running foes not change the engine at all.

I think I may have a fouled plug but have not checked it yet. I can remove the plug wire from the plug at the back right bank and it does not change the running much.
I picked that one to test because that plug wire got against the header a month ago.
I did put new wires but did not check the plug, I plan on installing new plugs tomorrow.

I also have trouble codes that relate torque management but they have been there for over a year and several people have tried to fix it but no one had been able to.

I can not remember which wire is supposed to have the 12 volt and which has the 5 but I think the pink is 12v and yellow is 5v

I do not have a garage or carport and have to do my work outside, it was too cold today
rained Saturday hopefully I will be able to get something figured out tomorrow..

 

While it is true 97-98 PCM's are different from the newer ones the later model ones will work with some re-pining of the harness.
NO DEALER will do this however there are performance shops that will and also provide you with a tune for your specific modified car.
Also I will point out that PCM failures are extremely rare you need to find a more qualified shop then the local dealer, they will just throw parts at it until your broke or it happens to fix the car.

FWIW, my 1998 H/C & blower car has a 2002 PCM.

 

I doubt that you have a PCM failure, however, until you post a complete list of PCM DTCs that you obtain by reading them through the DIC, it is difficult to be positive or to provide any helpful guidance.

If it were me, I would get the car out of the STEALERSHIP and allow us to LEAD GUIDE AND DIRECT!

Bill

 

[QUOTE=Do I have any other options? I know there was not a lot of vettes made in 1997.[/QUOTE]



I agree with Bill, Have your PCM reinstalled and drive the car out of the shop....Or recover your PCM and flat bed the car out of the shop.
Back in the day, the 1997 corvette PCM was AC Delco PN 16232148...

AC Delco web site
http://parts-catalog.acdelco.com/cat...log_search.php
MODULE ASM,ENG CONT (REMAN)
Part Number: 218-12290
Product Notes:
Engine Control Computer
Veh Specific Flash Programming Required; Addtl Veh Specific On-car; Programming Must Be Performed, w/-OE# 16232148, 1 Per Veh
Per Vehicle: 1; Years: 1997-1997

Goose

 

Thanks Bill and 69, thats very generous of you guys offering assistance. My first thought also was the dealership doen't know what they are talking about, but they sent the PCM off through autozone to be rebuilt, it was sent back as non repairable. I assume the repair shop would have tested it. Thats the only reason I was leaning toward the dealer might know what he was talking about.

So is there a reputable PCM repair shop I could send the PCM to that could verify if it is infact the problem? There are tons of these on the internet does anybody have any experience with any of them? If I could verify the PCM was good, I would not mind letting you guys walk me through troubleshooting.

I'm like jeffwilson34, I don't have a garage or carport to work in at the moment, its been below freezing and rain/sleet here the past couple of days. Thats the only reason I took it to the stealership to begin with.

The dealer ship smoke tested the engine (what ever that means) and found and repaired a couple of vacuum leaks prior to blaming the PCM.

Will a 98 PCM work in a 97?

 

AC Delco PCM PN 218-12290 is only for a 1997 Corvette, (not applicable for a 1998 corvette).
Interesting is the AC Delco site shows the following for this P/N
CHEVROLET(1)1997-1997
CORVETTE(1)1997-1997

1997 V8-350ci 5.7L F/I Vin G

PONTIAC(10)1997-2002

FIREBIRD(6)1997-2002

2002 V8-350ci 5.7L F/I Vin G

2001 V8-350ci 5.7L F/I (MEX)

2000 V8-350ci 5.7L F/I (MEX)

1999 V8-350ci 5.7L F/I (MEX)

1998 V8-350ci 5.7L F/I (MEX)

1997 V8-350ci 5.7L F/I Vin P
FIREBIRD FORMULA(4)1998-2001
2001 V8-350ci 5.7L F/I Vin G

2000 V8-350ci 5.7L F/I Vin G

1999 V8-350ci 5.7L F/I Vin G

1998 V8-350ci 5.7L F/I Vin G

Goose

 

Wow! Do you think this will work? I'm going to go pick mine up tomorrow and compare it to the pics. I found a couple of these out of pontiac firebirds on ebay at a very reasonable price. If it came out of a pontiac will the dealer be able to flash it for my vette?

 

I have some serious concerns as to whether your shop working on your car is capable of actually fixing your car or finding parts such as this PCM…. Just surfing the net tonight, we found a couple of brand new PCM’s for your ride…
If your shop has your car parked because they can’t provide you a solution to your PCM issue, I highly doubt that your shop can properly program the replacement PCM for your car.
But then again, you could ask them if they are capable of programing the PCM…

FYI, make sure you search AC Delco Part Number: 218-12290, PM sent to you.
Goose

 

what is your location?
If you are anywhere near me, I still have my PCM sitting in the battery compartment. It would be easy to unplug and install on yours and see what happens.

I think I am finally getting close to fixing most my bugs,
The main one was the broken wires inside the insulation on the throttle sensor. A visual inspection would have never found them but thinks to the advise of a member I held one wire at the base of the plug and the other end as far back in the harness that I could and and pulled. 2 of them came apart right at the exact spot. They must have been damaged somehow. I did end up cutting all the wires at the same place and connecting them back with waterproof connectors that are designed for connecting electric firing systems to wires on professional fireworks displays. With them you do not strip the insulation just insert the two wires into slots and clamp down the tops with pliers till they lock. They are fully watertight and made to be used close to lots of heat and vibration, They can be used under water even.
My final problem was the MASS AIR FLOW pink wire not getting the 12 volts. I tracked that down to a similar problem that I am sure I caused when troubleshooting the Throttle position Sensor,

Good luck and like other people have said get it out of the dealership.
You said you are like me with no garage,
I have been knows to use a carwash when it was raining and I needed to do something and keep dry.

 

Thanks everybody for the responses. I picked my PCM up from the dealer today, it looks corroded pretty bad on the outside. I'm going to order the AC delco unit off ebay. I'll keep this thread updated.

 

Well still no luck, I contacted the seller on Ebay, the PCM is no longer available.

 

Found another one, PM's you the link, give them a call to confirm fitment> don't give up the hunt they are out there...can you post up photos of you PCM electrical connectors? Just want to see if it was a victim of the dreaded battery acid leak.
Goose

 

Thanks Jeff for your offer, I'm in west TN, I think you may be in east TN.

 

yes 25 miles east of knoxville.

I would be willing to ship it to you then let you ship it back but i suspect that would cost as much as a replacement.
Have you checked all the local junkyards?
Possibly Craigslist
surely someone around you has one that they could loan you.

Are there any active local corvette clubs in your area?


Mine was corroded on the outside also, they appear sealed very well, the plugs were all clean with no corrosion.

 

I agree with the others. Get you car out of there ASAP. From experience I can tell you that a bad MAF should not cause your engine to completley shut down at highway speeds. If I was a betting man, I would go with a bad Crank Position Sensor.............ask me how I know............

 

Well Daves Discount Auto didn't have one in stock, neither did parts Monkey. Still on the hunt.