Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK BRAKE FLUID LEVEL
NOTE:
This DTC must be active for the results of this test to be valid.
1. Check the brake fluid level.
  Was the brake fluid level low?
  
  Yes
  - Repair as needed.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 2
BRAKE FLUID LEVEL SWITCH SIGNAL VOLTAGE BELOW 0.68 OF A VOLT
1. Ignition on, engine not running.
2. With the scan tool, read Brake Fluid Level Switch Sense voltage in the BCM.
  Is the voltage below 0.68 of a volt?
  
  Yes
  - Go To 3
  No
  - Perform the ABS INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
BRAKE FLUID LEVEL SWITCH INTERNAL FAILURE
1. Turn the ignition off to the lock position.
2. Disconnect the Brake Fluid Level Switch harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read the Brake Fluid Level Switch voltage in the BCM.
  Is the voltage approximately 5 volts?
  
  Yes
  - Replace the Brake Fluid Level Switch. Refer to SWITCH, BRAKE FLUID LEVEL, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK THE (B20) BRAKE FLUID LEVEL SWITCH SENSE CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the Brake Fluid Level Switch harness connector.
3. Disconnect the BCM C4 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (B20) Brake Fluid Level Switch Sense circuit.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (B20) Brake Fluid Level Switch Sense circuit.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 5
CHECK THE (B20) BRAKE FLUID LEVEL SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off to the lock position.
2. Measure the resistance of the (B20) Brake Fluid Level Switch Sense circuit in the Brake Fluid Level Switch harness connector to ground.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the (B20) Brake Fluid Level Switch Sense circuit for a short to ground.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 6
CHECK THE (B20) BRAKE FLUID LEVEL SWITCH SENSE CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Measure the resistance of the (B20) Brake Fluid Level Switch Sense circuit between the Brake Fluid Level Switch harness connector and the BCM C4 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the open in the (B20) Brake Fluid Level Switch Sense circuit.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE BCM FOR CORRECT OPERATION
1. Connect a jumper wire between the (B20) Brake Fluid Level Switch Sense circuit and the (Z901) Ground circuit in the Brake Fluid Level Switch harness connector.
2. Turn the ignition on.
3. With the scan tool, read the Brake Fluid Level Voltage.
  Is the voltage below 1.0 volt?
  
  Yes
  - Replace the Brake Fluid Level Switch.
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .