Circuit/System Testing

WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Refer to SIR Caution .

IMPORTANT: It is recommended that Component Testing be performed before Circuit Testing when diagnosing steering wheel controls.

Ignition OFF, disconnect the harness connector at the left and right steering wheel control switches.
Ignition ON, test for B+ between the ignition circuit terminal 1 and ground at the left harness connector.
- If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPM.
Test for less than 0.5 volt between the signal circuit terminal 4 and ground.
- If greater than 0.5 volt test the signal circuit for a short to voltage. If the circuit tests normal replace the IPM.
Install a 3-amp fused jumper wire at the ignition circuit terminal 1 at the left harness connector. Toggle the jumper wire between the signal circuit terminals 4 at the left and right harness connectors. Verify DTC B3622 sets.
- If the DTC does not set, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPM.
Reconnect the left switch.
Test for B+ between the ignition terminal 1 and ground at the right harness connector.
- If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal test or replace the left switch.
If all circuits test normal, test or replace the switch.