C0765
DTC C0750, C0755, C0760, or C0765
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 C0750 03
- Left Front Tire Pressure Sensor Low Voltage
DTC C0750 29
- Left Front Tire Pressure Sensor Too Few Pulses
DTC C0750 39
- Left Front Tire Pressure Sensor Internal Malfunction
DTC C0755 03
- Right Front Tire Pressure Sensor Low Voltage
DTC C0755 29
- Right Front Tire Pressure Sensor Too Few Pulses
DTC C0755 39
- Right Front Tire Pressure Sensor Internal Malfunction
DTC C0760 03
- Left Rear Tire Pressure Sensor Low Voltage
DTC C0760 29
- Left Rear Tire Pressure Sensor Too Few Pulses
DTC C0760 39
- Left Rear Tire Pressure Sensor Internal Malfunction
DTC C0765 03
- Right Rear Tire Pressure Sensor Low Voltage
DTC C0765 29
- Right Rear Tire Pressure Sensor Too Few Pulses
DTC C0765 39
- Right Rear Tire Pressure Sensor Internal Malfunction
Circuit/System Description
The tire pressure monitor system has a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly. As vehicle speed increases, centrifugal force closes the sensors internal roll switch, which puts the sensor into Drive mode. The body control module (BCM) receives and translates the data contained in the tire pressure sensor RF transmissions into sensor presence, sensor mode, and tire pressure. Once vehicle speed is greater than 40 km/h (25 MPH), the BCM waits for the first sensor to go into Drive mode, then checks if all sensors have gone into Drive mode. If one or more sensors do not go into these modes, or do not transmit at all, the BCM will set DTC C0750, C0755, C0760, or C0765 respectively.
Conditions for Running the DTC
Vehicle speed is greater than 40 km/h (25 MPH).
Conditions for Setting the DTC
* A sensor does not transmit or transmits invalid data to the BCM.
* A sensor low battery condition.
Action Taken When the DTC Sets
* The tire pressure monitor system indicator icon on the instrument cluster flashes for 1 min and then remains illuminated after the power switch is cycled ON and the instrument cluster bulb check is complete.
* If equipped, the driver information center displays a service tire monitor type message.
Conditions for Clearing the DTC
A current DTC will clear when the malfunction is no longer present and 1 power switch cycle occurs.
Diagnostic Aids
* Some aftermarket wheel valve stem holes are located further from the wheel rim than original equipment wheels. When using the tire pressure monitor diagnostic tool to activate a sensor, ensure the tool antenna is no further than 15 cm (6 in) from the sensor and is aiming upward.
* Aftermarket wheel valve system locations can cause a sensor to not function correctly.
* A sensor may have been damaged due to a previous wheel/tire service or flat tire event.
* The use of other than GM approved tire sealants can obstruct the sensor pressure sensing port and cause inaccurate tire pressure readings. If this condition is verified, remove the sealer from the tire and replace the sensor. Refer to Tire Pressure Indicator Sensor Replacement Service and Repair.
* The sensor activation procedure may have to be repeated up to 3 times before determining a sensor is malfunctioning. In the event a particular sensor's information is displayed on the tire pressure monitor diagnostic tool upon activation but the horn does not chirp, it may be necessary to rotate the wheel valve stem to a different position due to the RF signal is being blocked by another component.
* Occasionally sensor transmissions are not received by the BCM due to vehicle level radio frequency interference from items such as but not limited to aftermarket power systems, DVD players, CB radios, or metallic type window tinting.
* Occasionally sensors can become mislocated due to previous tire rotations where the sensor learn procedure was not performed. Always learn the sensors to ensure the DTC set is for that actual physical corner of the vehicle. Refer to Tire Pressure Indicator Sensor Learn Testing and Inspection.
* A sensor low battery condition will set a sensor DTC but will not illuminate the low tire pressure indicator or display a message on the driver information center, if equipped. The sensor battery condition can be verified in the scan tool BCM data list. If a sensor low battery condition is indicated on the scan tool, the sensor will need to be replaced. Refer to Tire Pressure Indicator Sensor Replacement Service and Repair.
Reference Information
Description and Operation
Tire Pressure Monitor Description and Operation Description and Operation
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Special Tools
EL-46079/J-46079 Tire Pressure Monitor Diagnostic Tool
Circuit/System Verification
1. Activate each tire pressure sensor and record each sensors transmission data and physical location with the tire pressure monitor diagnostic tool.
2. Verify the tire pressure monitor diagnostic tool displays the 8-digit ID number, accurate tire pressure +/- 27.6 kPa (4 psi), Relearn Mode, and at least a 1/4 graph signal strength for each sensor.
• If the tire pressure monitor diagnostic tool tool does not display all parameters
1. Replace the appropriate B2 tire pressure sensor.
2. Perform the Tire Pressure Indicator Sensor Learn Testing and Inspection.
• If the tire pressure monitor diagnostic tool tool displays all parameters
3. Verify tire pressure sensors ID and locations displayed on the scan tool match the ID's and locations recorded from the tire pressure monitor diagnostic tool.
• If the tire pressure sensors ID and locations displayed do not match
Perform the Tire Pressure Indicator Sensor Learn Testing and Inspection.
• If the tire pressure sensors ID and locations displayed match
4. Verify the sensor modes change to Drive with the scan tool while driving the vehicle above 40 km/h (25 mph) for greater than 2 minutes.
• If a sensor mode does not change to Drive
1. Replace the appropriate B2 tire pressure sensor.
2. Perform the Tire Pressure Indicator Sensor Learn Testing and Inspection.
• If the sensor modes change to Drive
5. Vehicle in Service Mode.
6. Enable the tire pressure monitor Learn mode. Learn 4 simulated sensor transmissions into the BCM with the tire pressure monitor diagnostic tool in simulate mode.
7. Verify that all 4 simulated sensor locations, ID's, and tire pressures displayed on the tire pressure monitor diagnostic tool match the corresponding scan tool parameters displayed.
• If the simulated sensor data does not match the scan tool sensor data
Replace the K9 body control module.
• If the simulated sensor data matches the scan tool sensor data
8. Perform the Tire Pressure Indicator Sensor Learn Testing and Inspection.
9. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Tire Pressure Indicator Sensor Replacement Service and Repair
* Tire Pressure Indicator Sensor Learn Testing and Inspection
* Control Module References Programming and Relearning
for BCM replacement, programming, and setup.