Circuit/System Testing

WARNING: This page is about a different car, the 2018 GMC Canyon and 2018 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the X1 harness connector at the S48A Multifunction Switch - Instrument Panel. It may take up to 2 min for all vehicle systems to power down.
Test for less than 15 Ω between the ground circuit terminal 14 and ground.
- If 15 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 15 Ω
Ignition ON.
Verify the scan tool Pickup Bed Cargo Lamp Command parameter is 0 %.
- If not 0 %
1. Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit terminal 18 and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If 0 %
Install a 3 A fused jumper wire between the signal circuit terminal 18 and ground.
Verify the scan tool Pickup Bed Cargo Lamp Command parameter is 100 %.
- If not 100 %
1. Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 18 and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - Go to next step: If less than 1 V
3. Test for less than 2 Ω in the signal circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K9 Body Control Module.
- Go to next step: If 100 %
Test or replace the S48A Multifunction Switch - Instrument Panel.