Buick Rendezvous/Pontiac Aztek BCM Repair

Buick Rendezvous 02-07, Pontiac Aztek 01-06 BCM Troubleshooting Guide

Disclaimer:
This guide applies only if your rebuilt BCM is still experiencing issues after our repair service. Please complete the checks below before assuming the BCM is faulty.

1. Confirm the symptom

Verify the reported concern applies to one or more of the following:

• Power door locks not working
• Power windows not working
• Power seats not working

Confirm whether the issue is:

• Constant or intermittent
• Affecting all doors/windows/seats or only specific ones

Attempt operation from:

• Driver controls
• Passenger controls (if applicable)
• Key fob (for door locks)

2. Check fuses and power feeds

Locate all BCM-, body-, and interior-related fuses (dash and under-hood).

With key ON, confirm:

• Battery (B+) voltage present at BCM constant power pins
• Ignition/ACC voltage present at BCM switched power pins (if applicable)
• Good ground at all BCM ground pins
  • Perform a voltage drop test if possible (preferred over continuity alone)

A blown fuse or missing power/ground must be resolved before suspecting the BCM.

3. Inspect BCM connectors and wiring

Disconnect the BCM and carefully inspect for:

• Bent, pushed-out, or corroded pins
• Loose terminals or partially seated connectors
• Signs of moisture intrusion or contamination

Inspect nearby harness routing for:

• Pinched, stretched, or chafed wiring
• Previous aftermarket work or splices

Reseat all connectors fully and ensure locking tabs are engaged.

4. Check related switches and actuators

If only one function is affected (example: windows only):

• Verify window switches, door lock switches, or seat switches are not physically damaged
• Test known-good switches when possible
• Confirm actuators or motors are not mechanically seized

If multiple interior functions are failing together, BCM involvement is more likely.

5. Network and communication checks

Scan the vehicle with a capable scan tool.

Confirm:

• BCM appears on the network
• DTC U1096 – Loss of communication with BCM (if present)
• No network-wide communication faults affecting multiple modules

If the BCM does not appear on the network:

• Reconfirm power, ground, and fuse integrity
• Inspect communication wiring for shorts or opens

6. After reinstalling a repaired BCM

• Clear all BCM-related DTCs
• Cycle the ignition fully (OFF → ON)
• Test all affected functions:
  • Door locks
  • Windows
  • Power seats

If applicable, perform any required relearn or initialization procedures using a factory-level scan tool.

7. If the issue remains

If:

• Power and ground are confirmed good
• Fuses and wiring check out
• Switches and actuators are functional
• Network communication issues persist

Please contact us with:

• Vehicle year/make/model
• Stored DTCs
• Results of the above checks

This information allows us to determine the next appropriate step.