Need Help!!!! Can't Figure it Out!
Thread Starter
8th Gear
Joined: Feb 2013
Posts: 8
Likes: 0
From: Studio City CA
Need Help!!!! Can't Figure it Out!
My 95 LT1 is having issues. It is having hestitation issues, almost feels like a hiccup and it throws the check engine light runs rough and then light goes off and it is fine again. It can happen anytime, city street, downshifting, highway almost everywhere. So I pulled the codes manually and I got a bunch of 13 and a couple 14 & 15's. So I replaced both the upstream O2 sensors and gues what, the same **** is happening. So we cleared the codes after replacing the sensors and so I pulled them again today and guess what the 3 same codes. A lot more 14 & 15's but a lot of 13's too. What am I missing. I'm about ready to drive it off a cliff. I need help with this one. Thank you for any help you can give me.
Thread Starter
8th Gear
Joined: Feb 2013
Posts: 8
Likes: 0
From: Studio City CA
That would be fantastic but not thinking it is going to make it that far right now. It is pissed off. Maybe if your out this way you could stop by and scan it. I pulled the codes manually put I know the scanner can do more. Let me know
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
http://chevythunder.com/199295_lt1_trouble_codes.htm
13 Oxygen sensor circuit wiring/connection 55 Lean fuel monitor
14 Coolant sensor high temp. indicated 58 Trans Fluid high temp. indicated
15 Coolant sensor low temp. indicated 59 Trans Fluid low temp. indicated
16 Ignition low resolution pulse not detected 61 Low R134A pressure indicated
21 TPS signal voltage high 63 Right heated O2 sensor lean indicated
22 TPS signal voltage low 64 Right bank O2 sensor lean indicated
23 IAT sensor low temp. indicated 65 Right bank O2 sensor rich indicated
24 VSS fault, no pulse indicated 66 A/C pressure sensor low pressure
25 IAT sensor high temp. indicated. 67 A/C pressure sensor circuit fault
26 EVAP purge control solenoid circuit.
27 EGR vacuum solenoid circuit 68 A/C relay fault
28 Transmission range control circuit 69 A/C relay fault
29 Secondary air injection circuit 70 A/C high pressure indicated
32 EGR failure 71 A/C evap sensor low temp indicated
33 MAP sensor signal high 72 VSS signal circuit error
34 MAP sensor signal low 73 Trans. pressure solenoid current surge
36 Ignition faulty high resolution signal 74 Traction control system
37 TCC brake switch stuck ON 75 Transmission system low voltage
38 TCC brake switch stuck OFF 77 Cooling fan relay control
39 Clutch switch error 79 Trans. temp sensor high temp. indicated
41 No ignition control circuit 80 Trans. component harness fault
42 Ignition control module circuit 81 Trans 2-3 shift solenoid circuit
43 Knock sensor wiring open or shorted 82 Trans 1-2 shift solenoid circuit
44 Lean exhaust detected 83 reverse switch inhibit circuit
45 Rich exhaust detected 84 Skip shift or 3-2 shift solenoid circuit
46 VATS pass key circuit fault 85 TCC stuck ON
47 Knock sensor module or circuit 90 TCC solenoid circuit fault
91 Skip shift lamp circuit
48 MAF sensor circuit 97 VSS output signal voltage low
50 System voltage low 99 TACH output circuit
51 PROM/EEPROM error
53 System voltage high
Description of error codes and possible fixes
Code 13- Oxygen Sensor circuit. Check for wiring and connections problems from the O2 sensor back to the ecm. If no problem is found, replace sensor.
Code 14- Coolant sensor circuit-high temperature indicated. Verify engine is not overheating, and correct any cooling system related problems first. Check the wiring and connections to the sensor. Replace sensor.
Code 15- Coolant sensor circuit-low temperature indicated. Verify engine is not under cooling, such as a thermostat sticking open. Check wiring and connections to sensor. Replace sensor.
14 Coolant sensor high temp. indicated 58 Trans Fluid high temp. indicated
15 Coolant sensor low temp. indicated 59 Trans Fluid low temp. indicated
16 Ignition low resolution pulse not detected 61 Low R134A pressure indicated
21 TPS signal voltage high 63 Right heated O2 sensor lean indicated
22 TPS signal voltage low 64 Right bank O2 sensor lean indicated
23 IAT sensor low temp. indicated 65 Right bank O2 sensor rich indicated
24 VSS fault, no pulse indicated 66 A/C pressure sensor low pressure
25 IAT sensor high temp. indicated. 67 A/C pressure sensor circuit fault
26 EVAP purge control solenoid circuit.
27 EGR vacuum solenoid circuit 68 A/C relay fault
28 Transmission range control circuit 69 A/C relay fault
29 Secondary air injection circuit 70 A/C high pressure indicated
32 EGR failure 71 A/C evap sensor low temp indicated
33 MAP sensor signal high 72 VSS signal circuit error
34 MAP sensor signal low 73 Trans. pressure solenoid current surge
36 Ignition faulty high resolution signal 74 Traction control system
37 TCC brake switch stuck ON 75 Transmission system low voltage
38 TCC brake switch stuck OFF 77 Cooling fan relay control
39 Clutch switch error 79 Trans. temp sensor high temp. indicated
41 No ignition control circuit 80 Trans. component harness fault
42 Ignition control module circuit 81 Trans 2-3 shift solenoid circuit
43 Knock sensor wiring open or shorted 82 Trans 1-2 shift solenoid circuit
44 Lean exhaust detected 83 reverse switch inhibit circuit
45 Rich exhaust detected 84 Skip shift or 3-2 shift solenoid circuit
46 VATS pass key circuit fault 85 TCC stuck ON
47 Knock sensor module or circuit 90 TCC solenoid circuit fault
91 Skip shift lamp circuit
48 MAF sensor circuit 97 VSS output signal voltage low
50 System voltage low 99 TACH output circuit
51 PROM/EEPROM error
53 System voltage high
Description of error codes and possible fixes
Code 13- Oxygen Sensor circuit. Check for wiring and connections problems from the O2 sensor back to the ecm. If no problem is found, replace sensor.
Code 14- Coolant sensor circuit-high temperature indicated. Verify engine is not overheating, and correct any cooling system related problems first. Check the wiring and connections to the sensor. Replace sensor.
Code 15- Coolant sensor circuit-low temperature indicated. Verify engine is not under cooling, such as a thermostat sticking open. Check wiring and connections to sensor. Replace sensor.
Thread Starter
8th Gear
Joined: Feb 2013
Posts: 8
Likes: 0
From: Studio City CA
Just replaced both O2 sensors yesterday with new AC Delco parts because it had over 75 13 codes in ECM. Cleared codes after replacement gave ECM time to relearn and still throwing code 13 along with 14 & 15. Car not hot and not cold. Can't figure it out. Going crazy with it.............
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Melting Slicks
Joined: Dec 2009
Posts: 2,241
Likes: 290
I'd have a look at the maf sensor, see if it needs to be cleaned. K&N air filters can cause the maf to get coated in oil. Do you have a K&N?
I had a car (not a vette) that I was checking that had a weird code not related to the maf, it had a tps code. The problem was the maf was installed backwards. I'm not saying thats your problem, just the hesitation you get could be a dirty maf sensor throwing weird codes.
I had a car (not a vette) that I was checking that had a weird code not related to the maf, it had a tps code. The problem was the maf was installed backwards. I'm not saying thats your problem, just the hesitation you get could be a dirty maf sensor throwing weird codes.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
The 94 and 95 Vette's have an OBDII Diagnostic connector but are not OBDII compliant.
To enter diagnostic mode.
Short pin 12 to pin 4 or 5.
Turn ignition on. Do not start the engine.
Connector located above driver side right knee and pin out looks like below.
01,02,03,04,05,06,07,08
09,10,11,12,13,14,15,16
After turning the ignition on the CCM will display
any Diagnostic Trouble Codes (DTC's) and the module for which they apply in an automatic sequence.
CCM=Module 1
PCM=Module 4
ABS/TCS EBTCM is Module 9
DERM (Airbag) is Module A
Each DTC is displayed for 3 seconds followed by a one second pause before the next DTC is displayed.
There is a three second pause between the DTC display sequence for each module.
The end of the DTC list for each module is indicated by
"----" being displayed in the speedometer.
If there is a communications problem between the CCM and the other modules, "Err" is displayed.
The particular module being interrogated is indicated on the trip monitor, and the DTC's are displayed in the speedometer.
To enter diagnostic mode.
Short pin 12 to pin 4 or 5.
Turn ignition on. Do not start the engine.
Connector located above driver side right knee and pin out looks like below.
01,02,03,04,05,06,07,08
09,10,11,12,13,14,15,16
After turning the ignition on the CCM will display
any Diagnostic Trouble Codes (DTC's) and the module for which they apply in an automatic sequence.
CCM=Module 1
PCM=Module 4
ABS/TCS EBTCM is Module 9
DERM (Airbag) is Module A
Each DTC is displayed for 3 seconds followed by a one second pause before the next DTC is displayed.
There is a three second pause between the DTC display sequence for each module.
The end of the DTC list for each module is indicated by
"----" being displayed in the speedometer.
If there is a communications problem between the CCM and the other modules, "Err" is displayed.
The particular module being interrogated is indicated on the trip monitor, and the DTC's are displayed in the speedometer.
Thread Starter
8th Gear
Joined: Feb 2013
Posts: 8
Likes: 0
From: Studio City CA
So it is saying to manually jump it in another fashion? I will try that when I get home tonight and see what happens and then I will let you know. Thank you again so much for all your help!!!!!!!!!!!!!!!
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
Check out the wiring, grounds, connectors and pin connections for corrosion for the temp sensor (ECT) in the water pump.
While you're driving, monitor the digital temperature for any erratic or off the wall quick indications especially when the engine acts up. It might give you a clue if you see a reaction.
While you're driving, monitor the digital temperature for any erratic or off the wall quick indications especially when the engine acts up. It might give you a clue if you see a reaction.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Should be a bleed valve on your thermostat. Get the front end higher than the rear somehow in your driveway pull the rad caps off and let it run and help burp the air out of the system then top it off again. It will run warm with air trapped in there could trigger those codes if its low again.
Drifting
Joined: Mar 2012
Posts: 1,492
Likes: 61
From: New Jersey
I did not see whether you replaced the coolant temp sensor. If not, I would first check the temp sensor connector and wiring and if that is good, I would replace the coolant temp sensor in the water pump (after checking coolant level as per Cuisinartvette),
Last edited by Silver96ce; Feb 4, 2013 at 11:25 PM.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Think its money well spent that thing can causeall types of wacky issues that are hard to track.
Tell your mech or whoever does it not to get the ign wet
Guys...how easy is this one to get to?
If it doesnt involve surgery perhaps I could knock it out quick
Tell your mech or whoever does it not to get the ign wet
Guys...how easy is this one to get to?
If it doesnt involve surgery perhaps I could knock it out quick