Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Ignition OFF, disconnect KR33 Auxiliary Heater Coolant Pump Relay, Ignition ON.
Verify a test lamp illuminates between the B+ circuit terminal 85 and ground
- If the test lamp does not Illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp
2. Test for less than 2 Ω in the B+ circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF, remove the test lamp
2. Test for infinite between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - if infinite resistance, test or replace the KR33 Auxiliary Heater Coolant Pump Relay.
- If the test lamp illuminates
Connect a test lamp between the ignition circuit terminal 86 and the control circuit terminal 85.
Verify the test lamp turns ON and OFF when commanding the KR33 Auxiliary Heater Coolant Pump Relay On and Off with a scan tool.
- If the test lamp is always off.
1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V
3. Ignition OFF.
4. Test for less than 2 Ω in the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K20 Engine Control Module.
- If the test lamp illuminates
Test or Replace the KR33 Auxiliary Heater Coolant Pump Relay.