Pinpoint Test L: DTC C1288 - Pressure Sensor Main/Primary Input Circuit Failure

Anti-Lock Control

Pinpoint Tests

Pinpoint Test L: DTC C1288 - Pressure Sensor Main/Primary Input Circuit Failure

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 must be installed.

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

This pinpoint test is intended to diagnose the following:
- ABS module
- HCU



PINPOINT TEST L: DTC C1288 - PRESSURE SENSOR MAIN/PRIMARY INPUT CIRCUIT FAILURE

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

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L1 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 L2.

No
INSPECT the ABS module and HCU for damage. REPAIR or INSTALL new as necessary. If any other DTCs are retrieved, GO to the ABS Module DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures

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L2 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 Service and Repair 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 L3.

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.

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L3 MONITOR THE PRESSURE TRANSDUCER (XDUCERCAL) PID


- Ignition OFF.
- Disconnect: ABS Module C135 .
- Separate the ABS module from the HCU. For additional information, refer to Anti-Lock Brake System (ABS) Module Service and Repair.
- 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, 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 Service and Repair. CLEAR the DTCs. REPEAT the self test.

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

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