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Open Help Requests for GM
Help Request Answers
1991 Buick Century 3.3L No Start, Cuts out, Stall
vehicle sometimes is a no start and sometimes it will start and run but crappy. If you drive it down the road it will sputter, cut out, and eventually stall. I have spark, good fuel pressure, injector pulse, and compression. Need help badly. Any input is great... Trouble codes: 42 (electronic spark timing).		 View
1992 Buick Roadmaster 5.7L runs rough all rpm
Hello all, have this roadmaster come in a month ago for a lack of power and rough running. Checked fuel pressure spark etc. at that time found injector on passenger side not spraying fuel. Had battery voltage at positive side and could make it spray if I groun...		 View
1996 Buick Century 3.1L MIL Lamp on
The "Service Engine Soon" light is on all the time. We are unable to communicate with the PCM; in fact the scan tool is unable to talk to any module on the car. We accessed the PCM. All PCM powers and grounds check out OK. The wires from the DLC to the PCM are...		 View
1997 Buick LeSabre 3.8L No Start
hello techs buick has no start no service engine soon light wont comunacate with scanner securety light goes off when trying to start fuel presure 50 psi has spark no injector pulse fuel pump runs all the time when key is on fuel pump relay clicking on and off...		 View
1999 Buick Century 3.1L No Start
Hey GM techs! shop key tells me pcm sends initial serial data with key on to bcm and aldl. Without this bcm sets a security light and locks me out from a start situation. I can manually start the car by creating a ground on pin 86 at the starter relay. Bcms ra... Trouble codes: u1255 (generic class II communication fault).		 View
2000 Buick Regal 3.8L Excessive Emissions
We replace the cat converter twice ,we flush the radiator and we replace the thermostat making no difference, we ran the vehicle on the dyno , with the gas analyzer connected , then we externally activate the EGR valve and we saw the NOX coming down . However ...		 View
2001 Buick LeSabre 3.8L Steering
cust state that she is have trouble getting the car out of park in the mounings. and then there is a electric snapping noise in the left front door speaker sub wolfer area when you open up one of the other 3 doors. for the getting out of park i have already ch...		 View
2004 Buick Rendezvous 3.6L MIL Lamp on
Vehicle Starts & runs. Trans. not shifting and error message in Odometer Display. was wanting to know if anyone has any common places the wiring may be rubbing. We checked all visible wiring for chaffing. Pins #2 of the DLC & Pin#58 PCM are testing 7.73K Ohms....		 View
2001 Cadillac DeVille 4.6L evap
i need help on this car intalled new purge valve oem from cadi. the light comes back with in 1 min of driving p0443 and inspection monitors all ready exp. evap and sec.air put no sec.air code. thank you Trouble codes: P0443 (evap canister purge valve).		 View
1998 Chevrolet Malibu 2.4L Poor Idle Quality, Hesitation, Cuts out, Misfire, MIL Lamp on
This vehicle came in running very poorly. I have found various problems with several systems as you can tell by the repair history.(the exhaust cam was even off a tooth due the the tensioner malfunction) Now I have isolated a misfire and bucking going up hill ... Trouble codes: p0300 (multiple cylinder misfire), P0420 (catalyst efficiency below threshold), P0171 (lean bank 1), P0174 (rich bank 1), P0125 (excessive time to achieve closed loop), P1171 (lean bank 1 on acceleration).		 View
2000 Chevrolet Malibu 3.1L MIL Lamp on
Car came in mil light on with P0442 purge valve had charcoal in it smoked system found vent valve open all the time replaced all three parts road tested car three times for 10 miles customer picked up car Friday Saturday light came on same code smoke test agai... Trouble codes: P0442 (evap small leak detected).		 View
2002 Chevrolet Cavalier 2.2L MIL Lamp on
vehicle was test driven several times for a total of 55 miles. returned to customer as fixed. cust returned 3 days later 100 more miles and stated all dash lights coming on again. codes u1016-1064 and 1088 returned. sdm burned again. could a loss of ground cau... Trouble codes: U1064 (loss of comm w bcm), U1301 (class 2 shorted to battery), U1000 (loss of seral communicaton 4 class 2), U1016 (no state of health from pcm), U1088 (loss of comm with sdm-sir).		 View
2004 Chevrolet Malibu 3.5L Harsh engagement 1-2nd shift harsh
Guys , Girls - Hello. First of all I dont do transmissions except to R&R and monor maintenance and repairs. What I have is this Malibu that had an awful noise in the front of it. After a closer look reveiled sludge and metal in the pan I just got a used one fr...		 View
2006 Chevrolet Suburban 1500 5.3L Cruise Control
I have a cruise control that is inop. Cruise light work when commanded by scanner and scanner shows all controls working correctly. There is a code that resets right a way in the BCM (B2961 Key in Ign. fault). We found the button was broken when the lock cylin...		 View
1999 GMC K3500 6.5L abs module
vehicle came in with a blown rear brake line, after replaceing the line unable to get any pressure to the rear wheel cylinders or the front brake calipers, good pressure to the abs module from the master cylinder, brake pedal is high & firm not spongy...abs mo...		 View
2000 GMC Yukon XL 1500 5.3L No Start
Got this 2000 GMC yukon 4wd customer stalled when driving. whats happening is i have no injector pulse and no signal to the fuel pump relay i do have correct power and ground at the relay but no power signal from ECM. I can control the fuel pump relay with Tec...		 View
2004 GMC Envoy 4.2L engine
any techs out there with input is greatly appericated. i've got a 2004 gmc envoy with an intermittent engine vibration ( not a missfire ), the engine shakes enough to be noticeable but not hard like a miss. customer hears a noise once in a while, none heard on...		 View
2005 GMC Yukon Denali XL 6.0L MIL Lamp on
weve got this 05 gmc yukon denali keeps throwing code P0455 if u clear the light two days later its back,weve smoke tested this vehicle with a tech II to seal the system countless times after replacing various parts that looked like they were leaking weve repl... Trouble codes: P0455 (large leak detected).		 View
2001 Oldsmobile Alero 3.4L Misfire
hi i got the cylender 2 misfire and i changed spark plugs wires fuel injecter ignition coil module Trouble codes: p0300 (random misfire).		 View
2002 Oldsmobile Intrigue 3.5L headlights, radio
Good Day All and thanks for your time. I'm working on a 2002 Olds Intrigue. The problem is when you remove the key and exit the vehicle, the headlights and radio stay on. The only way to power off the radio and lights is... hehe to scroll the dimmer switch fo...		 View

Fixes & Summaries for GM
Fix/Summary Answers
1998 Buick Riviera 3.8L outlet temperature
I THINK THIS ONE IS GONE. MY MISTAKE, SOMEWHERE IN A HVAC PICTURE I WAS LOOKING AT THE WRONG CONTROL ACTUATOR. I HAD REPLACED THE ONE ABOVE THE DRIVERS SIDE TEMP DOOR ACTUATOR, SWAPPED THE TWO OF THEM AROUND AND EVERYTHING IS WORKING FINE NOW. THANKS TO EVERYO...		 5
1999 Cadillac Seville 4.6L door locks & switches
Paul from Ontario and I were on the same wave-length as far as many more splices being corroded. Again with the help of some excellent wiring diagrams from techs on here, I recognized the splice right next to the original splice that used a scotchlock design b...		 5
2000 Cadillac Seville 4.6L Hesitation, Misfire, MIL Lamp on
Hi guys. Cleaned and replaced all the grounds mentioned. Took about an hour. During that time key was one click forward showing only the prndl display and likely allowing power to numerous modules etc. When i went to start the car thinking i had done all i cou... Trouble codes: P0352 (Ignition coil 2 control circuit), P0353 (Ignition coil 3 control circuit), P0355 (Ignition coil 5 control circuit), P0358 (Ignition coil 8 control circuit).		 9
1998 Chevrolet K1500 5.7L Cuts out
Fixed it. Got 20 excellent replies, most of which pointed towards the fuel pressure issue as the problem. MAF was mentioned as a possibility and we did seriously consider that but found our MAF readings would increase at the rate expected to match rpms at all ...		 20
2002 Chevrolet Impala 3.8L MIL Lamp on
WELL AFTER TWO WEEKS OF TESTING AND RETESTING THE SYSTEM I FINALLY FOUND THE PROBLEM.THROUGH THE SCAN TOOL YOU CAN ACTIVATE THE AIR PUMP AND THE VACCUM SOLENOID THAT SUUPLIES VACCUM TO THE VALVE FOR THE AIR INJECTION SYSTEM,AT ONE POINT THE SOLENOID MUST OF GO... Trouble codes: PO410 (air injection system).		 17
2004 Chevrolet Tahoe 5.3L t-case
Well, we were able to fix the problem quickly on this one. Due to the mileage we decided to replace the motor/sensor assy. Thanks for all of the advise, you guys were right on the money!		 11
1995 GMC K2500 6.5L No Start, MIL Lamp on
found pcm intermittently sending 6+volts onto ckp sensor signal wire causing internal ckp sensor open circuit between terminals "a" & "c" (spec. between "a" & "c" is 900-1200 ohm) Trouble codes: 19 (crankshaft position sensor).		 2
2001 GMC Yukon 5.3L dash gauges
thanks all for the replys. We did ck for ground connections on motor cyl head. this did have a remote starter that we took off I hate those things. all the fuses in fuse box were tight. Customer has a time set up to remove dash cluster. The vehical was b...		 11
2005 GMC Sierra 3500 6.6L Hesitation, Cuts out, Misfire
I got 4 replies on this, and am thankful for the advice. Brent and Justin were the closest on this. What I found is the wiring ti the IDM was shorting on the alternator bracket. It has a support arm for the wiring and I guess it supported it a little to much. ... Trouble codes: P0016 (cam and crank correlation), P0301 (missfire 1 cyl.), P0335 (crank sensor), P0341 (cam sensor), P1223 (inj. 1 output circuit).		 4
2001 Oldsmobile Intrigue 3.5L MIL Lamp on
It was an air valve on the right side of the engine, as many of you had suggested - thanks for your help!! Haven't gotten to the transmission code yet. Trouble codes: P0410 (Secondary Air Injection System), P1811 (Max Adapt and Long Shift).		 7
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