Pinpoint Test C: DTCs C0044:28, C0044:49 and C0044:64

Anti-Lock Control

Pinpoint Test C: DTCs C0044:28, C0044:49 and C0044:64

Normal Operation

The ABS module uses internal pressure sensors to determine correct operation by monitoring internal Hydraulic Control Unit (HCU) hydraulic pressures. These DTCs set if the brake pressure sensor signals do not match. This fault could set by either an internal ABS module failure or a pressure sensor failure. The pressure sensors are internal to the HCU (Hydraulic Control Unit) and cannot be serviced separately.

- DTC C0044:28 (Brake Pressure Sensor "A": Signal Bias Level Out of Range / Zero Adjustment Failure)- this DTC sets if the brake pressure sensor signals do not match. This fault could set by a misadjusted stoplamp switch or improperly installed brake pedal. An internal ABS module failure or a pressure sensor failure can also cause this DTC to set. When the ABS module sets DTC C0044:28, a message is also sent to the Transmission Control Module (TCM) along the High Speed Controller Area Network (HS-CAN) bus. After received this message from the ABS module, the TCM (Transmission Control Module) places the automatic transmission into NEUTRAL. There is no corresponding DTC set in the Transmission Control Module (TCM).

- DTC C0044:49 (Brake Pressure Sensor "A": Internal Electronic Failure)- this DTC sets if the brake pressure sensor signals do not match. This fault could set by either an internal ABS module failure or a pressure sensor failure.

- DTC C0044:64 (Brake Pressure Sensor "A": Signal Plausibility Failure)- this DTC sets if the brake pressure sensor signals do not match. This fault could set by either an internal ABS module failure or a pressure sensor failure.

This pinpoint test is intended to diagnose the following:

- ABS module

- HCU (Hydraulic Control Unit)

PINPOINT TEST C : DTCs C0044:28, C0044:49 AND C0044:64

C1 CHECK THE STOPLAMP SWITCH, CRUISE CONTROL DEACTIVATOR SWITCH AND BRAKE PEDAL AND BRACKET

- Inspect the stoplamp switch, cruise control deactivator switch and brake pedal assembly, verify there is no brake pedal pressure unintentionally applied due to incorrect stoplamp switch, cruise control deactivator switch or brake pedal installation.

Are the stoplamp switch, cruise control deactivator switch and brake pedal OK?

Yes
If DTC C0044:28 is set, GO to C3.

Otherwise, GO to C2.

No
REPAIR or INSTALL new components as necessary.

C2 CHECK FOR DTC C0044:49 AND/OR C0044:64 TO RETURN

- Ignition ON.

- Using a scan tool, clear all ABS module CMDTCs (Continuous Memory Diagnostic Trouble Codes).

- Test drive the vehicle at speeds greater than 32 km/h (20 mph).

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

Is DTC C0044:49 and/or C0044:64 present?

Yes
GO to C3.

No
The system is operating correctly at this time. The concern may have been caused by air trapped in the hydraulic brake system. REFER to Brakes and Traction Control on bleeding the base brake system. TEST the system for normal operation.

C3 CARRY OUT THE BRAKE PEDAL SWITCH ADJUSTMENT PROCEDURE

- Refer to Brake Pedal Switch Adjustment Adjustments.

Did the stoplamp switch and cruise control deactivator switch pass the brake pedal switch adjustment test?

Yes
GO to C4.

No
INSTALL a new stoplamp switch or cruise control deactivator switch as required.

C4 CHECK FOR CORRECT ABS MODULE TO HCU (Hydraulic Control Unit) TORQUE VALUES

- Verify all ABS module-to-HCU (Hydraulic Control Unit) fasteners are tightened to their correct torque specifications. Refer to Specifications.

Are the ABS module-to-HCU (Hydraulic Control Unit) fasteners tightened correctly?

Yes
INSTALL a new ABS module. REFER to Hydraulic Control Unit (HCU) Service and Repair. TEST the system for normal operation.

No
TIGHTEN all ABS module-to-HCU (Hydraulic Control Unit) fasteners. CLEAR the DTCs. GO to C5.

C5 CHECK FOR DTCs C0044:28, C0044:49 AND/OR C0044:64

- Test drive the vehicle at speeds greater than 32 km/h (20 mph).

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

- Record all ABS module DTCs.

Is DTC C0044:28, C0044:49 and/or C0044:64 present?

Yes
INSTALL a new HCU (Hydraulic Control Unit). REFER to Hydraulic Control Unit (HCU) Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern was likely cause by incorrectly tightened fasteners.