C0774

DTC C0774

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0774 00

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Low Tire Pressure System Performance

Circuit Description

The electronic brake control module (EBCM) receives a serial data message from the tire pressure monitor (TPM) system when low tire pressure is detected. The EBCM will adjust the responses of vehicle stability enhancement system (VSES) to have optimal vehicle control when active.

Conditions for Running the DTC

* Vehicle speed is 32 km/h (20 mph), or greater for 1 minute.

* VSES is active.

Conditions for Setting the DTC

The EBCM receives a serial data message of low tire pressure is detected.

Actions Taken When the DTC Sets

* The EBCM adjusts the VSES responses to compensate for a low tire pressure condition to maintain optimal control of the vehicle.

* No warning indicators and/or messages will be displayed.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present.

* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

Note:
During normal diagnostic and/or repair verification technicians may find that the ABS, Traction Control and/or Stabilitrak indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.

If the ABS, Traction Control and/or Stabilitrak telltales are ON with no DTCs set, perform the following steps:

1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.

2. Ignition ON, if the ABS, Traction Control and/or Stabilitrak telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.

3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.

4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

ABS Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

Verify tire pressure. Refer to Symptoms - Tire Pressure Monitoring Symptoms - Tire Pressure Monitoring.