GM Automotive Technicians Technical Discussion and Fixes for Oct 18, 2005

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	Help Request	Answers
	1995 Buick Park Avenue 3.8L crank no start VIN: 1G4CW52K5S I have a code P1629 passkey theft deterent failure. I have read all data's test procedure for this but cannot find a wiring diagram to show position of wires in the decoder and where they go to. I am supposed to check voltage at wire A3 but I do not see any ma...	View
	1995 Buick Roadmaster 5.7L ride control VIN: 1G4BR82P13 occasionally elc compressor will run with key off and run the battery down. Driveway where vehicle is parked is sloped. Could that trigger the compressor as the vehicle attempts to level itself? The compressor has yet to run since its parked in my flat and lev...	View
	1995 Cadillac DeVille 4.9L ride control VIN: 1ASDEW4345 I have read all of the previous posts about this problem but am unable to find out if you can disable the suspension light without changing the struts. The struts test fine and are at the correct height the system functions fine but I have the annoying service...	View
	1996 Cadillac DeVille 4.6L ride control (vcrss) VIN: 1G6KD52Y6T This vehicle came in with RSS codes RC0038-Pump fault and RC0060-LF position sensor fault. Vehicle bottoms out in rear over small bumps. Found compressor pump faulty and replaced. Checked left front position sensor and found connector ok-no water or debris ins...	View
	1988 Chevrolet Camaro 2.8L pre-ignition VIN: 1G1FP2154J this camaro pings on any kind of acceleration outher than very light. it wont do it cold but will do it as soon as it starts to warm up.moderate to heavy accelleration will result in a serious rattle.when i block off egr vent solenoid vac line it gets much bet...	View
	1992 Chevrolet S10 2.5L Poor Idle Quality, Surge, Stall VIN: 1GBCS10AXP This is the local post office's delivery vehicle, an S10 chassis with as postal truck body. Vehicle came in for stalling at idle, driver had to keep his foot on the gas to keep it running. Only stall after idling for a little bit, starts right back up every ti... Trouble codes: 44 (lean exhaust)	View
	1996 Chevrolet Blazer 4.3L Speed Sensor loses communication to pcm VIN: 1GNDT13W4T This vehicle came in in no shift mode we drove and drove fine. Called customer and stated no problem we were told to drive vehicle further we did lost speedo and trans went to limp mode checked vss and was fine . After 12 hrs of tracing down wires we finally c...	View
	1997 Chevrolet S10 2.2L Starter VIN: 1GCCS1440V Hope someone can help me with this headache, Last year vehicle was towed in with a no start, had power to starter when cranking. Needed starter, put new starter in. Made alittle noise when starting, put a small shim in even though its a no shim starter. Sounde...	View
	1997 Chevrolet S10 2.2L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GCCS1440V This vehicle came in with a misfire at idle, runs fine when you get to 1500 rpm and up. We have replaced both coils due to cracks in them, wires because of arcing out, plugs also because of fouling. Missfire started on #4 cylinder did cylinder balance test w/ ...	View
	1998 Chevrolet Blazer 4.3L srs VIN: 1GNDT13W1W Hello all you GM gurus. I have A code b1036 (Discriminating Sensor Open or Shorted to Voltage) that comes and goes. When it turns the SRS light on it does not stay for very long (10-30 seconds). I have checked connections at both front sensors and at the SDM. ...	View
	1999 Chevrolet K2500 7.4L Brake Pedal VIN: 1GCGK23J5X Customer came to us with complaint of vehicle not stopping. He said he had to stop hard and then brakes didn't work rightand ABS light on. Went to a shop and they replaced all wheel speed sensors, front pads and rear shoes, turned drums & rotors. He said it st...	View
	2002 Chevrolet Prizm 1.8L MIL Lamp on VIN: 1Y1SK528X2 I have code p1349. I have pulled the solenoid out and can make it work off the car with 12v. Then I cked it on the car. I gave it 12v + and the the engine dies. So I would say it changes the timing. Test drive and light goes on again. I read MOD testing and it... Trouble codes: P1349, P0440, P0441, P0446	View
	2002 Chevrolet Impala 3.4L fuel guage VIN: 2G1WF55E12 Have 5 volt referance to fuel sender unit.When turning key on guage goes to full then drops to Empty. No voltage change occurs at this time. What do you think seen this before thanks in advance for your help. Mike Cox	View
	2002 Chevrolet Corvette 5.7L door locks VIN: 1GIYY22G72 We find door locks do not ever lock with ether door switch or the key remote and auto lock is inopertive. They will unlock by the remote and the door switches. We checked all fuses, ok. scaned codes and has (for left door module B2282 clean battery fault, B228...	View
	2005 Chevrolet Silverado 2500 HD 6.0L tires VIN: 1GCHK29U35 To chevy truck guys,thanx in advance.I recently purchased a 05 silverado 2500 HD.I want to up grade the original 245/75 16 tires.Can i go bigger without lift or reprograming.reprograming although is not out 100%.Any info is greatly appreciated.	View
	2000 GMC Savana 3500 5.7L 3 rd gear VIN: 1GDHG31R3Y When you step down real hard (Fleet Vehicle Hard) it won't shift up. If you let off just a bit it will shift fine. We replaced the throttle cable because it had a bad spot starting in it after that the customer complained off the transmission not upshifting or...	View
	2000 GMC Safari SL 4.3L Hesitation, Surge, no powert VIN: 1GKDM19W1Y We are having a problem with this vehicle. Upon acceleration, this vehicle will hesitate, backfire, and have no power. Almost like retarded timing. We checked the fuel pressure, ignition system. Also checked the PCM. The only odd thing we see is the Cam positi...	View
	2002 Pontiac Sunfire SE 2.2L No Start VIN: 1G2JB12452 Came in on hook no start. All IPC lamps operating normal, no security lamp flashing. Got out mastertech to check cranking RPM & vehicle started. Drove into shop & retrieved codes. Checked module status key off BCM & radio respond. Key on PCM, BCM & radio respo... Trouble codes: U1000 (Loss of serial comm class 2), P1626 (Theft deterant start fuel signal not recieved), B2707 (Gear shift unlock circuit low input), B2958 (Security system sensor data circuit hi), U1088 (u1096-), U1096	View
	2000 Saturn LS2 3.0L Misfire, MIL Lamp on VIN: 1G8JW52R0Y car initially came in with p0171. returned 2 weeks later with p0171 and p0174, system lean. alldata says to check for fuel pressure, vacuum leak, exhaust leak, restricted fuel injector(s), maf prob, water in fuel. says if o2 b1s1 is greater than 1.2 and o2 b1s... Trouble codes: P0171 (system lean bank 1), P0174 (system lean bank 2)	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1997 Buick LeSabre Custom 3.8L Poor Idle Quality, MIL Lamp on, idles to high VIN: 1G4HP52K8V Thanks again IATN Group as always the IATN crew comes thru again, It was the o-ring on the pcv valve. something so simple could have tied us up for hours. Thanks again Mike [...] Trouble codes: P0121.	17
	1999 Buick Century Limited 3.1L a.c. control motors VIN: 2G4WY52M5X This one took a multiple repair to fix the problem. IATN had part of the fix on the tech base. Robert from NC (a friend of mine) sent me an email and asked if I had tried the fix posted on the tech base. That fix involves physically removing the actuator motor...	3
	1998 Cadillac Catera 3.0L MIL Lamp on, Speedo & PS VIN: WO6VR52R8W First I would like to thank John, Brent & Chuck for responding. I might have led everyone off track when I said the EBTCM seemed to test ok but that was the result upon testing by a ecm rebuilder. Anyhow when we got the car back it was very symptomatic so afte... Trouble codes: 1844 (1740 -), 1740 (501 -), 501.	3
	2001 Cadillac DeVille 4.6L Poor Idle Quality, Surge, Stall, MIL Lamp on VIN: 1G6KD54YX1 I took a few of the injectors to a 'fuel laboratory', and had them tested, no problem there, so I took the good advice from Stephen in Florida, and went after the boot between the throttle body & the intake, sure enough it was ruptured. nice move caddy, we all... Trouble codes: P0171 (bank one too lean), P0174 (bank two too lean).	13
	1992 Chevrolet K1500 Cheyenne 5.7L cooling system VIN: 1GCEK14K0P Thank you, everyone, First I know which end of the thermo goes down, but thank you for makeing me review, the fan clutch was changed, the belt was properly routed. pulled the intake manifold and lo and behold metal pieces on the end saying put to rear was at t...	29
	1993 Chevrolet Corsica LT 3.1L long crank VIN: 1G1LT53T0P We replaced tsp sensor. Which fixed the hi idle problem. And replaced fuel pressure regulator, for the long cranking time.	14
	1994 Chevrolet Astro CL 4.3L Excessive Emissions, Poor Idle Quality, Poor Fuel Economy VIN: 1GNEL19W4R Thanks for all the replys, you were right on to pull the plenum and inspect the fuel injector assm. In this case the return line under the plenum had split at the steel fitting and was leaking fuel into the plenum causing the rich idle condition. This part was...	14
	1997 Chevrolet S10 2.2L Hesitation, Cuts out, Stall, interm ext crank VIN: 1GCCS1448V Sorry for the delay. This was a difficult fix. Our first diagnosis was correct when we replaced fuel injectors. However, what compounded the problem was that those four injectors were listed as the correct application but were actually the wrong design. We fin...	8
	1997 Chevrolet Lumina 3.1L intake VIN: 2G1WL52M8V Well I want to thank all that said to use A gasket on the oil pump drive hsg . I Use a new o–ring again and added a gasket The hold down bolt thread was wet with oil I ran a wire thur bolt hole it went all the way to The oil pan so I added sealer to the bolt a...	34
	2000 Chevrolet Suburban 1500 LT 5.3L Cuts out, Misfire, MIL Lamp on VIN: 3GNFK16T6Y We have retested the oxygen sensors and the catalytic converter - we did a back pressure test on the new converter and sure enough it was plugged - we replaced the converter with an OE part - reset all the codes and test drove for 20 miles - no problems since ... Trouble codes: P0420 (Catalyst efficiency bank 1), P0300 (multiple cylinder misfire).	14
	2002 Chevrolet S10 2.2L Excessive Emissions VIN: 1GCCS1944X I did not post this help requist a Tech used iATN with out asking. I have delt with the problem. I would have replaced the Catalytic Converter with a Factory Part, given the data he posted. Infact that was the fix. Most responces agreed with replacing the Co...	13
	2004 Chevrolet Silverado 3500 6.0L Blend doors VIN: 1GBJC34U94 Thanks for the three replies I received. They were helpful. The actual problem was caused by a build-up of dirt in the heater case area along with a VERY poor design on GM's part. This is a contractor's truck and had a bit of dried mud on the floor on both s...	3
	2005 Chevrolet Silverado 2500 HD 6.0L starter VIN: U55F872587 Well I finally got a free second to look over the vehicle. Well all those who said look at the battery cable you was right on the money. I reached down and the cable for the negative was loose. I tighten it and it fixed the issue right away. Thank you all for ...	23
	2002 Saturn L100 2.2L Hesitation VIN: 1G8JS54F22 hi .there well this car its hitting the road w/o fix customer wants the car like it is . and is running fine if slow open the throtle.she came last friday for another check and I record a movie which I review at home on pc . I found the long fuel trim stay at ...	9

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