Diagnostic Test

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

CHECK FOR ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (B20) BRAKE FLUID LEVEL SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Brake Fluid Level Switch harness connector.
3. Disconnect the BCM C1 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (B20) Brake Fluid Level Signal circuit.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (B20) Brake Fluid Level Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (B20) BRAKE FLUID LEVEL SIGNAL CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Measure the resistance of the (B20) Brake Fluid Level Signal circuit between the Brake Fluid Level Switch harness connector and the BCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the open in the (B20) Brake Fluid Level Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Z910) GROUND CIRCUIT FOR AN OPEN
1. Using a 12-volt test light connected to 12-volts, check the (Z910) Ground circuit at the Brake Fluid Level Switch harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (Z910) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE BCM FOR CORRECT OPERATION
1. Turn the ignition off.
2. Reconnect the BCM C1 harness connector.
3. Connect a jumper wire between the (B20) Brake Fluid Level Signal circuit and the (Z910) Ground circuit at the Brake Fluid Level Switch harness connector.
4. Turn the ignition on.
5. With the scan tool, read the Brake Fluid Level.
  Does the Brake Fluid Level display Low Level?
  
  Yes
  - Replace the Brake Fluid Level Switch in accordance with the Service Information. Refer to SWITCH, BRAKE FLUID LEVEL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the BCM in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .