Circuit/System Testing

Ignition OFF and all vehicle systems OFF. Disconnect the X2 harness connector at the B110 Battery Sensor Module. It may take up to 2 min for all vehicle systems to power down.
Test for less than 10 Ω between the ground circuit terminal 1 X2 and ground.
- If greater than 10 Ω
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.
- If less than 10 Ω
Reconnect the X2 harness connector at the B110 Battery Sensor Module.
Test for less than 2 Ω between terminal 1 X2 and battery negative terminal.
- If greater than 2 Ω
  Repair the open or high resistance in the ground connection.
- If less than 2 Ω
Disconnect the X1 harness connector at the B110 Battery Sensor Module.
Verify a test lamp illuminates between B+ terminal 2 X1 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 good 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 resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the B110 Battery Sensor Module.
- If the test lamp illuminates
Disconnect the harness connector at the B18 Battery Current Sensor.
Test for less than 10 Ω between the low reference circuit terminal 2 and ground.
- If 10 Ω or greater
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Test for less than 2 Ω in the low reference 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 less than 10 Ω
Ignition ON.
Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 1 and ground.
- If less than 4.8 V
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Test for less than 2 Ω in the 5V reference 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 greater than 5.2 V
1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the 5 V reference circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the K20 Engine Control Module.
- If between 4.8 - 5.2 V
Test for 11.8 - 13 V between the signal circuit terminal 3 and B+
- If not between 11.8 - 13 V
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - 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 K20 Engine Control Module.
- If between 11.8 - 13 V
Replace B18 Battery Current Sensor