× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for June 23, 2011
International Automotive Technicians' Network (iATN) - Members Only
Next
(Also Available: All, Asian, Chrysler, European, Ford, GM.)
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.

Open Help Requests for GM
Help Request Answers
1995 Chevrolet C3500 7.4L Upshift/Output Speed VIN: IGDGC34N9S
I first checked power to trans it is good, then saw intermittent output speed cutout, changed the output speed sensor no change. checked the output speed on a scope both at the trans and at the drac module saw good waveform, so i checked the digital output of ...
View
1996 Chevrolet K1500 5.7L No Start
Super busy day and then this drops on our lap. No codes, fuel pressure good, fuel volume and quality good.Spark weak but sufficient, I think.No RPMs on tach or scanner.Can work injectors by grounding circuit at injector connector.Nice square wave form from cra...
View
1999 Chevrolet c6500 7.2L rear housing VIN: 1GBJ6H1C3X
i need the torque specs for the bolts on the rear housing to block. can't seem to get cat to tell me! thanks in advance.
View
2002 Chevrolet Astro 4.3L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, MIL Lamp on VIN: 1GCDL19X52
Runs bad engine miss stalls no power Trouble codes: P0335 (Ckp a circuit problem), P0341 (Cmp sensor circuit out of range)
View
2003 Chevrolet Malibu 3.1L Surge, MIL Lamp on
I got a 2003 Chevrolet Malibu 3.1 and got a code p1635. The code is 5-volt reference 1 circuit voltage is out of tolerance. The flow chart say's The powertrain module provides 5-volts to the flowing sensors: map,egr,ftp,tps. The conditions for setting the DTC ... Trouble codes: P1635
View
2003 Chevrolet Impala 3.4L Red warning light VIN: 2G1WF52E83
This non-ABS Impala has the red brake warning light on until you depress the emergency brake pedal, then it goes off most times. Sometimes it will just stay on no matter what. Monitoring the BCM you can see the input for the E-brake, on & off. Monitoring IPC i...
View
2005 Chevrolet Tahoe LT 5.3L Cuts out, Stall VIN: 1GNEC13T65
vehicle will run until 120-125 degrees is reached then cuts reference signal to coils,crank reference is within spec,replaced crank sensor,and throtle actuator,cleaned and applied di-electric grease to all fuses and grounds to wiring harness no wiring proplems...
View
2006 Chevrolet Express 2500 4.8L backup lamp VIN: 1GCGG25V46
this vehicle has no back up lites when shifted in reverse. at one point i installed a 15amp fuse in caivity #18 (underhood) the backup lite worked for about 2 minutes then it shorted the fuse. afterwards that fuse will short immediately. i have checked the wir...
View
2007 Chevrolet Suburban 1500 LTZ 5.3L Remote VIN: 1GNFK16317
I have this 07 suburban that i replaced battery in key fob and reprogramed with tech 2. Went right through programming fine and remote works for about 2 minutes then is inop. If you insert key in door and unlock door, remote now works again for 2 minutes. If i...
View
2007 Chevrolet Silverado 1500 LT 5.3L Door Locks, Radio, Gauges VIN: 2GCEC13J77
Truck came in. Driver says driving at 60 mph. Will lose power to dash and radio.(radio will clear loses time and channels) door lock go crazy going up and down. Engine loses power. So don't know if trans is acting up. A very short time (seconds)truck take off ...
View
2008 Chevrolet Cobalt LS 2.2L Electronic steering VIN: 1G1AK58F08
Well there is a first for everything.I have this cobalt that my used car dealer brought to me for pulling hard to the right.When i test drove it,it was hard to turn to the left but smooth as can be going right.So i put it on the lift,popped off the tires and c...
View
2008 Chevrolet Silverado 2500 HD WT 6.6L Trailer Brak VIN: 1GCHK23658
Posting this for a tech at a fleet location. SERVICE TRAILER BRAKE message is displayed always. Scan returns no codes in BCM. Disconnecting plug at trailer brake module (inboard left rear frame rail) allows trailer gain to display for a few seconds before it d...
View
2009 Chevrolet Tahoe LT 5.3L No Start, Cuts out, Stall VIN: 1GNEC13T65
vehicle will run for 2-5 minutes with no problem then shuts down no spark,fuel pressure is within specs,codes were for loss of comunication to throttle actuator,which i replaced to no avail,the symtoms remain the same.I have tested and inspected the wiring har...
View
1997 GMC K1500 Suburban 5.7L Ecmb 20amp fuse VIN: 1GKEK13R6V
I have replaced the 4L60E and runs fine. Replaced the battery and cleaned the posts. Now vehicle repeatedly blows the 20amp ECMB fuse under the hood. Have done the following: put old battery back in, blows fuse. Unplugged PCM, blows fuse. Unplugged ignition sw...
View
1998 GMC Safari SLT 4.3L Steering/Brakes VIN: 1GKEL19WXW
Pump failed in April (no steering or brakes). In June the serpentine belt started to squeel. Replace belt and had no change. Replace PS pump on 6/18, problem gone. lost steering and brakes at low RPM on the 19th, replace pump on the 20th. Lost steering and bra...
View
2004 GMC c8500 7.8L No Start VIN: 1GDM8C1374
This one is for the deisel people...Thanks in advance for the ones that take the time to help. It is loosing its prime intermitenly some times it will crank right up sometimes it dosent, it dosent have a pattern ,It seems to use more fuel from the drivers side...
View
2007 GMC Canyon SL 2.9L Ignition, alarm VIN: 1GTCS14997
This is my personal vehicle. It will intermittently not start and the Passlock system will engage. Vehicle will restart after waiting the required 10 mins for the Passlock to reset. Thought that maybe it was a key issue, but even using the spare key does not ...
View
1996 Oldsmobile Cutlass Supreme 3.1L MIL Lamp on VIN: 1G3WH12M2T
Voltage testing at cam sensor connector showed ignition voltage, good ground, and no voltage at signal wire. Checked circuit 630 at PCM and found no 5 volt output. Continuity from PCM to sensor good and signal circuit not grounded. Replaced Pcm with reflashed ... Trouble codes: P0341
View
1997 Pontiac Grand Prix GTP 3.8L Hesitation VIN: 1G2WP5215V
Hey Y'all! This is more of a 'second opinion' post. The customer is complaining of stuttering/hesitation during accel and while crusing. Only code set is for the EGR pintle position. On test drive, it took a bit, but I did notice a 'stutter' on accel and whene... Trouble codes: P1406 (EGR Pintle valve position circuit)
View
2006 Saturn Relay-2 3.5L all wheel drive VIN: 5GZDX23L76
We keep getting a code for L/front sensor and the all wheel drive disabled would come on. We had a deffective wheel bearing which led us to thinking the abs mod was bad. We replaced that but it didn't help, we replaced the wheel bearing again and the code stop...
View

Fixes & Summaries for GM
Fix/Summary Answers
2004 Buick Rendezvous CXL 3.6L ebcm VIN: 3G5DB037X4
Hello there well this vehicle is fixed. What we found here was a bad ground at G117 which is a large black/white wire that bolts with a star washer on the left side of the transaxle housing removing and replacing the eyelet and cleaning up the case did the tri...
8
1985 Chevrolet Camaro Sport 2.8L fuel guage VIN: 1G1FP7S1FN
1985 Camaro came in with fuel guage that would drop to empty when the lights are turned on. I checked the grounds to the instrumnt cluster and the lights. I overlooked the chassis ground by the battery. Cleaned and relocated chassis ground and problem solved. ...
4
1993 Chevrolet Camaro 3.4L No Start, Misfire VIN: 2G1FP22SXP
This was my first help request and I couldn't believe how many people responded. Thanks. We haven't fixed the car yet. I have now load tested the wiring, changed ignition switch, tested key and security system, good fuel pressure and flow, checked relays, chec...
23
2000 Chevrolet Impala 3.8L Poor Idle Quality VIN: 2G1WH55R3Y
Replacing the MAF sensor repaired the hard start and no idle flare. Now, at startup, the idle flares to 1500 rpm and the car starts nice. Thanks for all the replies. I had several that suggested a MAF sensor problem. This gave me the confidence to replace the ...
25
2003 Chevrolet Avalanche 1500 5.3L valvetrain VIN: 3GNEK13T03
Sorry for the delay in posting a fix, we did find metal contamination in the engine oil, likley cam/lifter failure, sold customer on used engine due to low cost & high avaliability of 5.3L engines, swapped motor & all is good!! Thanks again for the replies, h...
7
2001 GMC Sierra 2500 HD SLE 6.0L TCC apply VIN: 1GTHK29U91
Hi to everyone and thanks to all those who replied with tips concerning the no TCC apply with this 4L80E trans. I removed the unit for a complete overhaul and although the clutches and hard parts were in good overall condition for 225,000 miles I did find worn...
15
2003 GMC Envoy SLE 4.2L Hesitation, Stall, MIL Lamp on, Runs lean VIN: IGKDT13S53
THANKS FOR ALL THE REPLIES, MANY HIT THE PROBLEM PERFECTLY. CODE P0171, FUEL TRIM LTFT +20. DIDN'T WANT TO RUN COLD, RAN POORLY AT BEST WHEN WARMED UP. WE HAD PULLED THE FRONT O2 SENSOR ABOUT AN HOUR AFTER IT WAS HERE, BUT DIDN'T REALIZE PCM HAS REV LIMITER FE... Trouble codes: P0171 (Lean all banks).
13
Prev (Also Available: All, Asian, Chrysler, European, Ford, GM.) Next