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W/UH3



DTC C0750, C0755, C0760, or C0765 (W/UH3)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptors
DTC C0750
- Left Front Low Tire Pressure Sensor

DTC C0755
- Right Front Low Tire Pressure Sensor

DTC C0760
- Left Rear Low Tire Pressure Sensor

DTC C0765
- Right Rear Low Tire Pressure Sensor




Diagnostic Fault Information






Circuit/System Description

The tire pressure monitor (TPM) system has a radio frequency (RF) transmitting pressure sensor in each wheel/tire assembly. As vehicle speed increases, centrifugal force closes the sensor internal roll switch, which puts the sensor into rolling mode. The sensor signals are received by the tire pressure receivers mounted near each wheel. Each receiver has a 5-volt reference circuit, a low reference circuit, and signal circuit connected to the tire pressure module. The tire pressure module transmits the individual sensor signals to the remote control door lock receiver (RCDLR) which translates the data contained in the tire pressure sensor RF transmissions into sensor presence, sensor mode, and tire pressure. Once vehicle speed is 40 km/h (25 mph) or greater, the RCDLR waits for the sensors to go into rolling mode. If one or more sensors do not go into rolling mode, or do not transmit at all, the RCDLR will set DTC C0750, C0755, C0760, or C0765 respectively.


Conditions for Running the DTC

Vehicle speed is 40 km/h (25 mph)or greater for 2 minutes.


Conditions for Setting the DTC

* A sensor does not transmit for 18 minutes.
* A malfunctioning tire pressure receiver.
* An open/high resistance, short to voltage, or short to ground in the tire pressure module power or ground circuit.
* An open, short to voltage, short to ground, or high resistance in a tire pressure receiver 5-volt reference, low reference, or signal circuit.



Action Taken When the DTC Sets

* The tire pressure monitor indicator icon on the instrument panel cluster (IPC) flashes for 1 minute and then remains illuminated after the ignition switch is cycled ON and the IPC bulb check is complete.
* The driver information center (DIC) displays the suspect tire pressure as dashes.
* The DIC 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 ignition cycle occurs.
* The RCDLR automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Diagnostic Aids

* Some aftermarket wheel valve stem holes are located further from the wheel rim than original equipment wheels. When using the TPM special 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 stem 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 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) .
* Occasionally sensor transmissions are not received by the RCDLR due to vehicle level RF interference from items such as but not limited to aftermarket ignition systems, DVD players, CB radios, or metallic type window tinting.
* 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 special 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 sensors can become mislocated due to previous tire rotations where the sensor learn procedure was not performed or stray sensor transmissions have been received from other vehicles . Always learn the sensors to ensure the DTC set is for that actual physical corner of the vehicle. Refer to Tire Pressure Sensor Learn (Programming and Relearning) .
* 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 DIC, if equipped. The sensor battery condition can be verified in the scan tool RCDLR 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
Schematic Reference

Tire Pressure Monitoring System Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Tire Pressure Monitor Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for Scan Tool Information
Special Tools

J-46079 Tire Pressure Monitor Diagnostic Tool


Circuit/System Testing

1. Ignition OFF, test for less than 2.0 ohms of resistance between the tire pressure module ground circuit terminal 10 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

2. Ignition ON, verify that a test lamp illuminates between the tire pressure module terminal 1 and ground.

• If the test lamp does not illuminate, test for an open/high resistance or short to ground in the B+ circuit. If the circuit tests normal, replace the tire pressure module.

3. Ignition OFF, disconnect the harness connector at the affected tire pressure receiver.
4. Ignition OFF, test for less than 2 ohms of resistance between the low reference circuit terminal 3 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If circuit tests normal, replace the tire pressure module.

5. Ignition ON, test for 4.75-5.25 volts between the 5-volt reference circuit terminal 1 and ground.

• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the tire pressure module.
• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the tire pressure module.

6. Ignition OFF, replace the affected tire pressure receiver with a known good part from one of the other locations.
7. Ignition ON, use the special tool to simulate the tire pressure sensor. Verify the scan tool displays an accurate tire pressure that matches 27.6 kPa (4 psi) of the special tool simulation display parameters.

• If the parameters do not match, test the signal circuit for a short to ground, open/high resistance, or short to voltage. If the circuit tests normal, replace the tire pressure module.

8. Using the J-46079 , activate each tire pressure sensor and record each sensors transmission data and physical location. Verify the J-46079 displays an 8-digit ID number, accurate tire pressure 27.6 kPa (4 psi), Learn Mode, and at least a 1/4 graph signal strength displayed.

• If any of the parameters listed above are not displayed, replace the suspect tire pressure sensor.

9. Verify that the tire pressure sensors ID and locations displayed on the scan tool match the ID and location recorded from the special tool.

• If the ID and location do not match, perform the Tire Pressure Sensor Learn (Programming and Relearning) procedure.

10. Test drive the vehicle above 40 km/h (25 mph) for greater than 2 minutes. With the scan tool, observe the suspect Pressure Sensor Mode data parameter. Verify the sensor mode changes to Rolling.

• If the suspect Pressure Sensor Mode does not change, replace the suspect tire pressure sensor.




Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Tire Pressure Indicator Sensor Replacement (Service and Repair)
* Tire Pressure Indicator Receiver Replacement (RPO UH3) (Service and Repair)
* Low Tire Pressure Indicator Module Replacement (RPO UH3) (Service and Repair)
* Tire Pressure Sensor Learn (Programming and Relearning)
* Control Module References (Programming and Relearning) for RCDLR replacement, setup, and programming


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