GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 Accessories 🢒 Navigation Systems 🢒 DTC C0750, C0755, C0760, or C0765

Circuit Description

The tire pressure monitor (TPM) system has 4 radio frequency transmitting pressure sensors inside the wheel/tire assemblies. As vehicle speed increases to above 32 km/h (20 mph), the sensors internal roll switch closes which puts the sensors into drive mode. The sensors begin to transmit once every 60 seconds to the driver side antenna module. The data within this radio frequency transmission contains sensor identification, sensor mode, sensor status, and tire pressure. Once vehicle speed is greater than 32 km/h (20 mph), the antenna module waits for all sensors to go into drive mode. If one or more sensors do not go into drive mode, or do not transmit at all, the driver side antenna module 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 40 km/h (25 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 will clear when the malfunction is no longer present.
    • A history DTC will clear after 100 consecutive ignition cycles.

Diagnostic Aids
    • The tire pressure sensors transmit on the AM band and are received by the driver side antenna module thorough the AM/FM antenna grid in the vehicles rear window. Ensure the AM/FM antenna system is operating to specifications. Refer to Diagnostic Starting Point - Entertainment in Entertainment.
    • 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 .
    • Occasionally, sensor transmissions are not received by the driver side antenna module due to vehicle level radio frequency interference.
    • Some aftermarket wheel valve stem holes are located further form the wheel rim than the original equipment wheels. When using the J-46079 Tire Pressure Monitor Diagnostic Tool to activate a sensor, ensure the tool's antenna is no further than 6 inches from the sensor.
    • The sensor activation procedure may have to be repeated up to 3 times before determining a sensor is malfunctioning.

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 tool's display screen. Any more that 1/4 graph displayed can be considered good signal strength.

    2.

  2. This step tests if any sensors are mislocated.

    3.

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

    4.

  4. This step tests if the sensor's 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 in Vehicle DTC Information

2

Using the J-46079 Tire Pressure Monitor Diagnostic Tool, activate each tire pressure sensor and record each sensor's transmission data and physical location on the repair order.

Does the TPM diagnostic tool display each sensor's transmission data as an 8 digit ID number, accurate tire pressure +/- 2 psi, Learn Mode, good signal strength?

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 TPM diagnostic tool in simulate mode, learn 4 simulated sensor transmissions into the driver antenna module's memory.
  3. With the scan tool, observe all 4 sensor location, Ids and tire pressures.

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

Go to Step 5

Go to Step 8

5

Learn the tire pressure sensors. Refer to Tire Pressure Sensor Learn .

Did you complete the procedure?

Go to Step 6

--

6

  1. Test drive the vehicle above 32 km/h (20 mph) for 10 seconds.
  2. Observe the suspect Pressure Sensor Mode data parameter with the scan tool.

Does the suspect Pressure Sensor Mode data parameter change from Wake to Drive above 32 km/h (20 mph)?

System OK

Go to Step 7

7

Replace the suspect tire pressure sensor. Refer to Tire Pressure Indicator Sensor Replacement .

Did a horn chirp sound when learning the suspect sensor?

Go to Step 9

--

8

Replace the driver side antenna module. Refer to Radio Antenna Module Replacement in Entertainment.

Did you complete the replacement?

Go to Step 9

--

9
  1. Clear the DTCs with a scan tool.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

Go to Step 2

System OK