C1288

Anti-Lock Control

Pinpoint Test R: DTC C1288

Normal Operation

The ABS module monitors the pressure of the hydraulic brake system through the use of a brake pressure transducer. The transducer sends a signal to the ABS module that varies in relation to the amount of pressure applied to the brake pedal. The more pressure that is applied, the greater the signal send to the ABS module. The brake pressure transducer is internal to the Hydraulic Control Unit (HCU) and cannot be serviced separately. If a new brake pressure transducer is needed, a new HCU (Hydraulic Control Unit) must be installed.

- DTC C1288 (Pressure Sensor Main/Primary Input Circuit Failure)- If there is an incorrect connection between the ABS module and HCU (Hydraulic Control Unit), if the brake pressure transducer is faulted or if the ABS module is faulted internally, this DTC sets.

This pinpoint test is intended to diagnose the following:

- ABS module

- HCU (Hydraulic Control Unit)

PINPOINT TEST R : DTC C1288

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

R1 CHECK FOR FAULT REPEATABILITY

- Connect the scan tool.

- Ignition ON.

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

- Drive the vehicle at least 20 km/h (12 mph).

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

Is DTC C1288 present?

Yes
GO to R2.

No
INSPECT the ABS module and HCU (Hydraulic Control Unit) for damage. REPAIR or INSTALL new as necessary. If any other DTCs are retrieved, REFER to the ABS Module DTC Chart. Antilock Brakes / Traction Control Systems

R2 VERIFY THE ABS MODULE FASTENERS ARE TIGHTENED CORRECTLY

- Ignition OFF.

- Loosen each ABS module fastener and tighten to the correct torque specification. Refer to Anti-Lock Brake System (ABS) Module for the correct torque specification.

- Ignition ON.

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

- Drive the vehicle at least 20 km/h (12 mph).

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

Is DTC C1288 present?

Yes
GO to R3.

No
The system is operating correctly at this time. The concern may have been caused by an incorrectly installed ABS module. RETURN the vehicle to the customer.

R3 MONITOR THE PRESSURE TRANSDUCER (XDUCERCAL) PID

- Ignition OFF.

- Disconnect: ABS Module C135.

- Separate the ABS module from the HCU (Hydraulic Control Unit). Refer to Anti-Lock Brake System (ABS) Module .

- Connect: ABS Module C135.

- Ignition ON.

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

- With the ABS module separated from the HCU (Hydraulic Control Unit), monitor the XDUCERCAL PID.

Does the PID read less than 19,000 kPa (2,756 psi)?

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

No
INSTALL a new HCU (Hydraulic Control Unit). REFER to Hydraulic Control Unit (HCU) . CLEAR the DTCs. REPEAT the self-test.