GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Battery Voltage Signal: The scan tool displays 0-20 volts The scan tool displays the voltage as received by the BCM.

Shift Lock Solenoid Command: The scan tool displays Lock or Unlock. Lock indicates the control circuit is grounded. Unlock indicates the control circuit is not grounded.

Engine Control Module (ECM)

BPP Circuit Signal: The scan tool displays Applied or Released. The scan tool displays the status of the brake switch.

Transmission Control Module (TCM)

IMS: The scan tool displays Drive 3, Drive 4\Drive 3, Park\Reverse, Reverse, Drive 3\Drive 2, Drive 2, Park, Invalid, Neutral\Drive 4, Drive 4, Neutral, Reverse\Neutral, Drive 1, Drive 2\Drive 1 or Open for the LZ9. The scan tool displays the position of the transmission range switch.

TR Sw.: The scan tool displays Park, Reverse, Neutral, Drive 5, Drive 4, Drive 3, Drive 2 or Drive 1 for the L61 and LZ4. The scan tool displays the position of the transmission range switch.