For 1990-2009 cars

### Circuit 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 sensors internal roll switch, which puts the sensor into drive mode. The remote control door lock receiver (RCDLR) receives and translates the data from the tire pressure sensor into sensor, sensor mode and tire pressure. Once vehicle speed is greater than 20 mph then checks if all sensors are in drive mode. If one or more sensors do not go into drive mode, or do not transmit at all, the RCDLR will set DTC C0750, C0755, C0760, or C0765.

### DTC Descriptors

This diagnostic procedure supports the following DTCs:

• | 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

### Conditions for Running the DTC

Vehicle speed is at least 32 km/h (20 mph).

### Conditions for Setting the DTC

Any given sensor stops transmitting for 10 minutes.

### Action Taken When the DTC Sets

• | A DTC is stored in memory.

• | The driver information center (DIC) displays the SERVICE TIRE MONITOR warning message.

• | The DIC displays the suspect tire pressure as dashes.

### Conditions for Clearing the DTC

• | A current DTC clears when the malfunction is no longer present.

• | A history DTC will clear after 100 consecutive ignition cycles.

### Diagnostic Aids

• | 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 Sensor Learn .

• | Some aftermarket wheel valve stem holes are located further form the wheel rim than the original equipment wheels. When using the J-46079 to activate a sensor, ensure the tools antenna is no further than 6 inches from the sensor.

• | The tire pressure sensors transmit on the FM band and are received by the RCDLR through the antenna grid in the vehicles rear window. Visually inspect the antenna grid for any physical damage or poor connections at either end of the antenna.

• | Certain types of rear defroster grid malfunctions can create RF interference that may cause a TPM system malfunction. To determine if this condition is present, operate the vehicle within the condition for running and setting the DTC and verify the TPM malfunction only occurs when the rear defroster is turned On.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step tests if the sensors can transmit valid data with good signal strength in response to a low frequency activation. During this step it is important to observe the signal strength graph on the TPM tools display screen. Any more that 1/4 graph displayed can be considered good signal strength.

2. This step tests if any sensors are mislocated.

3. This step tests if the RCDLR can receive, learn and translate data contained in simulated sensor transmissions.

4. This step tests if the sensors internal roll switch is functioning properly.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Tire Pressure Monitoring System Schematics
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Using the J-46079 Tire Pressure Monitor Diagnostic Tool, activate each tire pressure sensor and record each sensors transmission data and physical location on the repair order. Does the J-46079 display all 4 sensor locations, IDs, and tire pressures? | Go to Step 3 | Go to Step 7
3 |

1. Turn ON the ignition, with the engine OFF.
2. Observe all 4 sensor IDs and their locations with a scan tool.

Do the IDs and their locations observed on the scan tool match the IDs and locations recorded on the repair order?

Go to Step 4

Go to Step 5

4 |

1. Enable the TPM learn mode. Refer to Tire Pressure Sensor Learn .
2. Using the J-46079 in simulate mode, learn 4 simulated sensor transmissions into the RCDLR memory.

Does the scan tool display all 4 sensor locations, IDs, and tire pressures?

Go to Step 5

Go to Step 8

5 | Learn the tire pressure sensors. Refer to Tire Pressure Sensor Learn . Did you complete the learn procedure? | Go to Step 6 | --
6 |

1. Test drive the vehicle 20 mph for 10 seconds.
2. Observe the suspect Pressure Sensor Mode data parameter with the scan tool.

Does the scan tool indicate that the suspect Pressure Sensor Mode changes from Wake to Drive?

System OK

Go to Step 7

7 | Replace the suspect tire pressure sensor. Refer to Tire Pressure Indicator Sensor Replacement . Did you complete the replacement? | Go to Step 9 | --
8 | Replace the remote control door lock receiver (RCDLR). Refer to Remote Control Door Lock Receiver Replacement . Did you complete the replacement? | Go to Step 9 | --
9 |

1. Clear the DTCs with the scan tool.
2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK