Circuit/System Testing

12 Volt primary battery current sensor circuit checks

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B18 Battery Current Sensor. It may take up to 2 min for all vehicle systems to power down.
2. 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.
   • Go to next step: If less than 10 Ω 
3. Ignition ON.
4. 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.
      • Go to next step: 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.
   • Go to next step: If between 4.8 - 5.2 V 
5. Test for 11.8 - 13 V between the signal circuit terminal 3 and B+
   • If less than 11.8 V 
   1. 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.
      • Go to next step: If less than 1 V
   2. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
   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.
      • Go to next step: If 11.8 V or greater 
   4. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
6. Replace the B18 Battery Current Sensor.
7. Verify that DTC P118C, P118D does not set while operating the vehicle within the Conditions for Running the DTC.
   • If the DTC sets 

     Replace the K20 Engine Control Module.

   • Go to next step: If the DTC does not set 
8. All OK.