Circuit/System Testing

Brake Fluid Level Sensor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B20 Brake Fluid Level Switch. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
   • If 10 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 10 Ω 
3. Ignition ON.
4. Verify the scan tool Brake Fluid Level Sensor parameter is Low.
   • If the parameter is not Low 
   1. Ignition OFF, disconnect the harness connector at the K17 Electronic Brake Control Module.
   2. Test for infinite resistance between the signal circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K17 Electronic Brake Control Module.
   • Go to next step: If the parameter is Low 
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
6. Verify the scan tool Brake Fluid Level Sensor parameter is OK.
   • If the parameter is Low 
   1. Ignition OFF, disconnect the harness connector at the K17 Electronic Brake 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.
      • 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 K17 Electronic Brake Control Module.
   • Go to next step: If the parameter is OK 
7. Test or replace the B20 Brake Fluid Level Switch.

Park Brake Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the B80 Park Brake Switch.
2. Verify that the B80 Park Brake Switch has no physical damage or incorrect installation.
   • If physical damage or incorrect installation is found 

     Test or replace the B80 Park Brake Switch.

   • Go to next step: If the inspection is OK 
3. Ignition ON.
4. Verify the scan tool Park Brake Switch parameter is Released.
   • If the parameter is Applied 
   1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
   2. Test for infinite resistance between the signal circuit terminal A 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 the parameter is Released 
5. Install a 3 A fused jumper wire between the signal circuit terminal A and ground.
6. Verify the scan tool Park Brake Switch parameter is Applied.
   • If the parameter is Released 
   1. Ignition OFF, disconnect the harness connector at the K9 Body 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.
      • 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 theK9 Body Control Module.
   • Go to next step: If the parameter is Applied 
7. Test or replace the B80 Park Brake Switch.