Circuit Description
The Tire Pressure Monitor (TPM) system has a radio frequency (RF) transmitting pressure sensor inside each wheel/tire assembly. As vehicle speed increases, centrifugal force closes the sensor's internal roll switch which puts the sensors into drive mode. The passenger door module (PDM) receives and translates the data contained in each sensor's RF transmission into sensor presence, sensor mode, and tire pressure. Once vehicle speed is 40 km/h (25 mph), or greater, the PDM waits for the first sensor to go into drive mode then checks if all sensors all sensors have gone into drive mode.
Conditions for Running the DTC
Vehicle speed is 40 km/h (25 mph), or greater for 2 minutes.
Conditions for Setting the DTC
Any given sensor does not go into drive mode, or does not transmit at all for 5 minutes.
Action Taken When the DTC Sets
| • | A DTC is stored in memory |
| • | The DIC displays the SERVICE TIRE MONITOR message. |
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 malfunction free ignition cycles. |
| • | Using a scan tool |
Diagnostic Aids
| • | Some aftermarket wheel valve stem holes are located further from the wheel rim than original equipment wheels. When using the J-46079 to activate a sensor, ensure the tool's antenna is no further than 15 cm (6 in) from the sensor. |
| • | The sensor activation procedure may have to be repeated up to 3 times before determining a sensor is malfunctioning. |
| • | 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 Sensor Learn . |
| • | Occasionally sensor transmissions are not received by the PDM due to vehicle level RF interference. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Tests if the sensors will 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 after the activate button has been pressed and released. Any more than 1/4 graph displayed can be considered good signal strength.
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Tests if any sensors are mislocated.
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Tests if the PDM can receive and translate data from simulated sensor transmissions
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Tests if the sensors internal roll switch is functioning properly.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Tire Pressure Monitoring System Schematics | ||||
1 | Did you perform the Tire Pressure Monitor Diagnostic System Check? | Go to Step 2 | ||
Using the J-46079 , activate each tire pressure sensor and record each sensor's transmission data and physical location on the repair order. Does the TPM tool display each sensor's transmission data as specified? | 8 digit ID number, accurate tire pressure +/- 2 psi, Learn Mode, Good Signal Strength | Go to Step 3 | Go to Step 7 | |
Do the Ids and locations displayed on the scan tool match the Ids and locations recorded on the repair order? | Go to Step 4 | Go to Step 5 | ||
Does the scan tool display all 4 sensor locations, Ids and tire pressures as specified? | LF Pressure Sensor ID-123401/LF Tire Pressure-10 psi, RF Pressure Sensor ID-123402/RF Tire Pressure-20 psi, RR Pressure Sensor ID-123403/RR Tire Pressure-30 psi, LR Pressure Sensor ID-123404/LR Tire Pressure-40 psi +/- 2 psi | 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 | -- | |
Does the scan tool display that the suspect Pressure Sensor Mode changes from Wake to Drive? | System OK | Go to Step 7 | ||
7 | Replace the suspect sensor. Refer to Tire Pressure Indicator Sensor Replacement . Did you complete the replacement? | Go to Step 9 | - | |
8 | Replace the PDM/window switch assembly. Refer to Door Lock and Side Window Switch Replacement - Passenger Side In Doors Did you complete the replacement? | Go to Step 9 | - | |
9 |
does the DTC reset? | Go to Step 2 | System OK | |
