Anti-Lock Brake System (ABS) and Stability Control

Anti-Lock Control

Pinpoint Test K: DTC C1105

Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number

Normal Operation

The ABS module communicates with the Cruise-Control Module (C-CM) over the High Speed Controller Area Network (HS-CAN) bus during adaptive cruise control operation. In some instances, the C-CM (Cruise-Control Module) will command the ABS module to automatically apply the brakes and slow the vehicle when necessary in order to maintain a safe distance to the vehicle in front. When this happens, the stop lamp control circuit CCA28 (GY/BN) is grounded by the ABS module, which closes the stoplamp relay, activating the stoplamps as the brakes are applied by the ABS module.

- DTC C1105 (Brake Lamp Short to Ground or Short to Power)- If the ABS module detects an open, short to ground, or short to voltage on the stoplamp relay control circuit, DTC C1105 is set.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- C-CM (Cruise-Control Module)

- ABS module

PINPOINT TEST K : DTC C1105

K1 CHECK STOPLAMP OPERATION

- Press the brake pedal and verify the correct operation of the stoplamps.

Are the stoplamps illuminated only when the brake pedal is pressed?

Yes
GO to K2.

No
REFER to Lighting and Horns.

K2 TEST THE STOPLAMP RELAY

- Disconnect: Stoplamp Relay.

- Measure the resistance between stoplamp relay pin-1 and pin-2, component side.

Is the resistance between 63 and 120 ohms?

Yes
GO to K3.

No
INSTALL a new stoplamp relay. CLEAR the DTCs. REPEAT the self-test.

K3 CHECK FOR VOLTAGE AT THE STOPLAMP RELAY CONTROL COIL

- Ignition ON.

- Measure the voltage between stoplamp relay cavity 2, circuit CBB36 (BU/BN) and ground.





Is the voltage greater than 10 volts?

Yes
GO to K4.

No
VERIFY Battery Junction Box (BJB) fuse 36 (20A) is OK. If OK, REPAIR circuit CBB36 (BU/BN). If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. Diagrams By Number

K4 CHECK THE STOPLAMP RELAY CONTROL GROUND CIRCUIT FOR AN OPEN

- Disconnect: ABS Module C135.

- Measure the resistance between stoplamp relay cavity 1, circuit CCA28 (GY/BN) and ABS module C135-36, circuit CCA28 (GY/BN), harness side.





Is the resistance less than 5 ohms?

Yes
GO to K5.

No
REPAIR circuit CCA28 (GY/BN). CLEAR the DTCs. REPEAT the self-test.

K5 CHECK THE STOPLAMP RELAY CONTROL GROUND CIRCUIT FOR A SHORT TO GROUND

- Measure the resistance between stoplamp relay cavity 1, circuit CCA28 (GY/BN) and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to K6.

No
REPAIR circuit CCA28 (GY/BN). CLEAR the DTCs. REPEAT the self-test.

K6 CHECK THE STOPLAMP RELAY CONTROL GROUND CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition ON.

- Measure the voltage between stoplamp relay cavity 1, circuit CCA28 (GY/BN) and ground.





Is any voltage present?

Yes
REPAIR circuit CCA28 (GY/BN). CLEAR the DTCs. REPEAT the self-test.

No
GO to K7.

K7 CHECK FOR CORRECT ABS MODULE OPERATION

- Disconnect: ABS Module C135.

- Check for:
- corrosion.
- pushed-out pins.
- spread terminals.


- Connect: ABS Module C135.

- Make sure that the connector is correctly seated.

- Connect the scan tool.

- Using the scan tool, clear all ABS module DTCs.

- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.

- Retrieve and record all ABS module DTCs.

Is the DTC C1105 still present?

Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.