check engine light..
10-30-2007, 04:32 PM
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check engine light..
So I was cleaning my interior and took off the gauge cover and noticed someone put black electrical behind the check engine light, I've had this car for 2 years now and just found this out and sure enough when i took the tape off and put things back together and started her up the light was on. I went and bought a code scanner hooked it up and 2 codes came up..
32:
Barometric pressure (BARO) sensor failure.
OR
Exhaust gas recirculation (EGR) vave diagnostic switch - closed during engine start-up or open when EGR flow requested by ERG.
OR
ERG/EVRV.
36:
Mass air flow (MAF) sensor - burn-off circuit problem.
OR
Transmission shift problem (electrically controlled transmission only)
OR
Direct ignition system (DIS) fault - loss of 24X signal or extra or missing pulses in electrical spark timing (EST) signal.
OR
Ignition system fault - loss of High Resolution Pulse signal.
The cars a '87 Irocz28 350TPI(auto).. and like i said this light has been on for who knows how long since it was blocked out.. Its been running perfectly fine though, but I'm curious if anything listed above is well REALLY critical since I may have been running like that for a long while. Also I have a feeling one ofthose codes are probaly from my oil pressure gauge not working? (Barometric pressure (BARO) sensor failure. = Oil Pressure?) Also before I bought it from the guy he said he just replaced the MAP sensor so maybe a code needs to be cleared?
Just trying to get some insight before I go digging through my car to try and find what the problems are.
offtopic stupid question:
are 3rdgen camaros suposto have posi rear ends? ive noticed recently that only my passanger side has been leaving rubber. when i could have sworn that my driver side did too a year ago.
32:
Barometric pressure (BARO) sensor failure.
OR
Exhaust gas recirculation (EGR) vave diagnostic switch - closed during engine start-up or open when EGR flow requested by ERG.
OR
ERG/EVRV.
36:
Mass air flow (MAF) sensor - burn-off circuit problem.
OR
Transmission shift problem (electrically controlled transmission only)
OR
Direct ignition system (DIS) fault - loss of 24X signal or extra or missing pulses in electrical spark timing (EST) signal.
OR
Ignition system fault - loss of High Resolution Pulse signal.
The cars a '87 Irocz28 350TPI(auto).. and like i said this light has been on for who knows how long since it was blocked out.. Its been running perfectly fine though, but I'm curious if anything listed above is well REALLY critical since I may have been running like that for a long while. Also I have a feeling one ofthose codes are probaly from my oil pressure gauge not working? (Barometric pressure (BARO) sensor failure. = Oil Pressure?) Also before I bought it from the guy he said he just replaced the MAP sensor so maybe a code needs to be cleared?
Just trying to get some insight before I go digging through my car to try and find what the problems are.
offtopic stupid question:
are 3rdgen camaros suposto have posi rear ends? ive noticed recently that only my passanger side has been leaving rubber. when i could have sworn that my driver side did too a year ago.
10-30-2007, 06:11 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Barometric pressure is the pressure of the air you and the car are breathing. It'll be higher at sea level, lower in Denver. And, it varies with the weather. If the previous owner changed the MAP sensor, when it is the BPS that was bad, that could easily be the reason the tape was over the light.
What's wrong with your oil pressure gage? It doesn't feed the computer, but that's something i would want working.
I'm not really familiar with the MAF sensor burn-off circuit, but I've heard talk about it many times on this Board.
Codes clear after awhile (50 starts comes to mind), so, if the light is on, it's been setting the codes since you've had the car.
Posi rears are not as common in 3rd gens as open rears. Worn out posis aren't that uncommon, either.
What's wrong with your oil pressure gage? It doesn't feed the computer, but that's something i would want working.
I'm not really familiar with the MAF sensor burn-off circuit, but I've heard talk about it many times on this Board.
Codes clear after awhile (50 starts comes to mind), so, if the light is on, it's been setting the codes since you've had the car.
Posi rears are not as common in 3rd gens as open rears. Worn out posis aren't that uncommon, either.
10-30-2007, 06:29 PM
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Car: 1987 IROC (parts car) '86 IROC
Engine: 5.7, None
Transmission: 700R4, None
Re: check engine light..
There is no Baro sensor in an 87 TPI. Code 32 is for an EGR fault. Code 36 is for a MAF burn off problem.
Neither one of those problems should be cause for alarm but, I would repair them just so things are 'right'. However, a malfunctioning EGR valve will cause pinging on moderate accelleration if doesn't open.
Neither one of those problems should be cause for alarm but, I would repair them just so things are 'right'. However, a malfunctioning EGR valve will cause pinging on moderate accelleration if doesn't open.
What's wrong with your oil pressure gage? It doesn't feed the computer, but that's something i would want working.
Codes clear after awhile (50 starts comes to mind), so, if the light is on, it's been setting the codes since you've had the car.
Posi rears are not as common in 3rd gens as open rears. Worn out posis aren't that uncommon, either.
Codes clear after awhile (50 starts comes to mind), so, if the light is on, it's been setting the codes since you've had the car.
Posi rears are not as common in 3rd gens as open rears. Worn out posis aren't that uncommon, either.
10-30-2007, 06:34 PM
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10-30-2007, 09:34 PM
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Car: 75 Beast
Engine: 383 +EBL Flash
Transmission: 700R4
Axle/Gears: 4.11 with 33"
Re: check engine light..
loljello
Code 32 gets set when ECM does not detect lean mixture (since there is no MAP sensor) during EGR test operation. Typical causes for this are blocked EGR passage from carbon buildup, blown EGR valve, bad EGR control solenoid, disconnected wiring harness. Troubleshot you can use this chart
http://www.chevythunder.com/egr_code_32.htm
Code 36 - This is a bit more involved. Your car is equipped with a hot-wire MAF, a platinum wire is heated 212 degrees F above the incoming air temperature. As air flows past the sensing element, it has a cooling effect. This increases the current needed to keep the sensing element at a constant temperature. The cooling effect varies directly with the temperature, density and humidity of the incoming air, so the current change is proportional to the air “mass” entering the engine. The output signal produced by the MAF sensor varies according to the application.
The hot-wire Bosch MAF sensors were used in 1985-89 GM 5.0L and 5.7L Tuned Port Injection (TPI) engines, generate an analog voltage signal that varies from 0 to 5 volts. Output at idle is usually 0.4 to 0.8 volts increasing up to 4.5 to 5.0 volts at wide-open throttle.
Code 32 gets set when ECM does not detect lean mixture (since there is no MAP sensor) during EGR test operation. Typical causes for this are blocked EGR passage from carbon buildup, blown EGR valve, bad EGR control solenoid, disconnected wiring harness. Troubleshot you can use this chart
http://www.chevythunder.com/egr_code_32.htm
Code 36 - This is a bit more involved. Your car is equipped with a hot-wire MAF, a platinum wire is heated 212 degrees F above the incoming air temperature. As air flows past the sensing element, it has a cooling effect. This increases the current needed to keep the sensing element at a constant temperature. The cooling effect varies directly with the temperature, density and humidity of the incoming air, so the current change is proportional to the air “mass” entering the engine. The output signal produced by the MAF sensor varies according to the application.
The hot-wire Bosch MAF sensors were used in 1985-89 GM 5.0L and 5.7L Tuned Port Injection (TPI) engines, generate an analog voltage signal that varies from 0 to 5 volts. Output at idle is usually 0.4 to 0.8 volts increasing up to 4.5 to 5.0 volts at wide-open throttle.
Bosch hot-wire units have a self-cleaning cycle where the platinum wire is heated to 1,000 degrees C (1,832 F) for one second after the engine is shut down. The momentary surge in current is controlled by ECM through a relay to burn off contaminants that might otherwise foul the wire and interfere with the sensor’s ability to read incoming air mass accurately.
To troubleshoot you can use this flow chart:
http://www.chevythunder.com/maf_code_36.htm
Typical causes are related to poor electrical connections, open or short in MAF circuit, defective MAF sensor burn-off relay, defective MAF sensor, or even defective ECM.
http://www.chevythunder.com/maf_code_36.htm
Typical causes are related to poor electrical connections, open or short in MAF circuit, defective MAF sensor burn-off relay, defective MAF sensor, or even defective ECM.
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