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jim sylvester

jim ... 3/30/2010

2002 Pontiac Montana Base 6 Cyl 3.4L

Preventive Maintenance

power lock on door panel won't lock but will unlock

both sides driver and passenger

1 Answer


HouseCallAuto 3/30/2010

The answer is definitely on this page of info I am posting for you. These confirmed fixes for your same problem on your same vehicle (Chevy Venture is the same) show that the cause (majority) is a corroded splice.

The power door locks unlock but do not lock. New Body Control Module (BCM) tried-same.
Tests/Procedures: 1. Check for about 12 volts at the Dark Blue wire to each door lock switch.

2. If no voltage dcheck for a corroded splice S311 under the passenger side carpet by the sill plate. Simply pull the carpet retainer from the right hand door opening and check for water in the wiring harness. Open the harness by unwrapping the tape and checking for a splice in the Light Blue wire. This is a metal crimp holding 3 Blue wires together. There is a splice in the White unlock circuit in the same area.

3. If still no voltage, cut the splice apart and check on the Body Control Module (BCM) side of the harness. If no voltage leaving the BCM, check for the vehicle to be equipped with option code UA6. If equipped, insert the door key into the key cylinders and rotate to check for a sticking key cylinder. Monitor the voltage on the Blue wire and check for any voltage to recover.

4. Repeat the same test using the lift gate key cylinder.

5. If voltage comes back on the blue wire when turning the key cylinders, replace the key cylinder. If voltage does not come back, cut the Red/Black wire at terminal C11 of the BCM. If the voltage now comes back, shorted Red/Black circuit. Disconnect each door key cylinder and recheck the Blue wire.
Potential Causes: Key Cylinder

Tech Tips: Turning the passenger tumbler fixed the problem (Stuck)
Diagnostic Codes: None
Author: Mark Owens
Average Reported Mileage: 82027

Confirmed Fix Summary

Confirmed Fix 7 - Splice S311
1 - Door Lock/Unlock Switch
1 - Passenger Key Cylinder Switch

Confirmed Fix Details

Tech Reported Fix Details Confirmed Fix
Chuck Dutterer
September 24, 2009 2002 Pontiac Montana, 3.4L
Repaired Splice S311 — Repaired the wiring under the carpet on the right hand side. Splice S311
Joe Langejans
July 06, 2009 2002 Pontiac Montana, 3.4L
Repaired Splice S311
- corroded splice S311 Splice S311
January 14, 2010 2004 Pontiac Montana, 3.4L *
Replaced Splice S311
- cheched for voltage at dark blue wire no voltage found corroded wire under carpet on passenger side repaired wire and it is working now Splice S311
Anton Kukharev
September 22, 2009 2004 Chevrolet Venture, 3.4L *
Repaired Splice S311
- corroded splice S311 under the passenger side carpet by the sill plate Splice S311
Gary Harvel
June 12, 2009 2002 Oldsmobile Silhouette, 3.4L *
Replaced Splice S311
- Repaired Splice S311 Also Repaired Yellow Splice For Rear Windows Splice S311
Ken Dornacher
February 11, 2010 2002 Chevrolet Venture, 3.4L *
Replaced Splice S311
- repaired the blue and white splices in right sill under carpet. Splice S311
John Bennett
March 25, 2009 2001 Chevrolet Venture, 3.4L *
Repaired Splice S311
- repair wire @ S311 Splice S311
November 26, 2008 2004 Pontiac Aztek, 3.4L *
Replaced Door Lock/Unlock Switch
- door lock switch Door Lock/Unlock Switch
Ted Seekins
May 30, 2008 2002 Chevrolet Venture, 3.4L *
Passenger Key Cylinder Switch
82,027 miles Passenger Key Cylinder Switch


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