Diagnostic Test

Turn the ignition on.

With the scan tool, read and record ABS DTCs.

With the scan tool, read and record Environmental Data (EV Data).

With the scan tool, erase ABS DTCs.

Cycle the ignition switch.

Apply brake and release while looking for brake switch status change on scan tool. If brake status changes skip next step. If no status change on brake switch continue.

Apply brake pedal for at least 1 minute then 1 minute with brake off.

With the scan tool, read ABS DTCs.

Does this DTC reset? 

Yes 

1. Go to  2).

No 

1. The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
2. Refer to ABS INTERMITTENT CONDITION .

Turn the ignition off.

Visually inspect the related wiring harness. Look for any pinched, chafed, pierced, and partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, and corroded terminals.

Were any problems found? 

Yes 

1. Repair as necessary.
2. Perform ABS VERIFICATION TEST .

No 

1. Go to  3).

Fig 1: Checking Brake Switch Signal Circuit Function Using Test Light

Courtesy of CHRYSLER LLC

Disconnect the Anti-Lock Brakes Module harness connector.

Turn the ignition on.

Using a 12-volt test light connected to 12 volts, probe the (B15) Secondary Brake Switch Signal circuit (Diesel) or the (B15) Brake Switch No. 1 Signal circuit (Gas) in the Anti-Lock Brakes Module harness connector.

Depress and release the brake pedal.

Does the test light illumination toggle from off to on within 4-5 mm of brake pedal travel? 

Yes 

1. Replace the Stop Lamp Switch in accordance with the SERVICE INFORMATION.
2. Perform ABS VERIFICATION TEST .

No 

1. Go to  4).

Fig 2: Checking Secondary Brake Switch Signal Circuit (Diesel) Or Brake Switch No. 1 Signal Circuit (Gas) For An Open

Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Stop Lamp Switch harness connector.

Measure the resistance of the (B15) Secondary Brake Switch Signal circuit (Diesel) or the (B15) Brake Switch No. 1 Signal circuit (Gas) between the Anti-Lock Brakes Module harness connector and the Stop Lamp Switch harness connector.

Is the resistance below 5.0 ohms? 

Yes 

1. Go to  5).

No 

1. Repair the (B15) Secondary Brake Switch Signal circuit (Diesel) or the (B15) Brake Switch No. 1 Signal circuit (Gas) for an open.
2. Perform ABS VERIFICATION TEST .

Fig 3: Checking Secondary Brake Switch Signal Circuit (Diesel) Or Brake Switch No. 1 Signal Circuit (Gas) For A Short To Ground

Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Stop Lamp Switch harness connector.

Measure the resistance of the (B15) Secondary Brake Switch Signal circuit (Diesel) or the (B15) Brake Switch No. 1 Signal circuit (Gas) between ground and the Anti-Lock Brakes Module harness connector.

Is the resistance below 10k ohms? 

Yes 

1. Repair the (B15) Secondary Brake Switch Signal circuit (Diesel) or the (B15) Brake Switch No. 1 Signal circuit (Gas) for a short to ground.
2. Perform ABS VERIFICATION TEST .

No 

1. Go to  6).

Measure the resistance on the (Z940) Ground circuit and ground in the Stop Lamp Switch harness connector.

Is the resistance below 5 ohms? 

Yes 

1. Replace the Stop Lamp Switch in accordance with the SERVICE INFORMATION.
2. Perform ABS VERIFICATION TEST .

No 

1. Repair the open in the (Z940) Ground circuit.