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 sensor into drive mode. The remote control door lock receiver (RCDLR) receives and translates the data contained in each sensor's RF transmission into sensor presence, sensor mode, and tire pressure. Once vehicle speed is 32 km/h (20 mph), or greater, the RCDLR waits for the first sensor to go into drive mode then checks if all sensors have gone into drive mode.
Condition for Running the DTC
Vehicle speed is 32 km/h (20 mph), or greater.
Conditions for Setting the DTC
Any given sensor does not go into drive mode, or does not transmit at all for 35 minutes.
Action Taken When the DTC Sets
| • | A DTC is stored in memory. |
| • | The 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 malfunction free ignition cycles. |
| • | Using a scan tool. |
Diagnostic Aids
| • | The sensor activation/scan procedure using the J-46079 TPM diagnostic tool with the J 41760 sensor activating tool, 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 . |
| • | Loss of, or low vehicle battery voltage, or disconnecting the RCDLR will cause the sensors Id codes to be erased from the RCDLR's memory and set all 4 of the sensor DTCs. If this condition is suspected, refer to Tire Pressure Sensor Learn . |
| • | Occasionally sensor transmission are not received by the RCDLR 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 magnetic activation. During this step it is important to observe the signal strength graph on the TPM tool's display screen when the sensor transmits. Any more than 1/4 graph displayed can be considered good signal strength. The TPM diagnostic tool can only store transmission data from 1 sensor at a time, therefore the scan button must be pressed and released prior to each sensor activation.
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Tests if the RCDLR 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 | ||
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 6 | |
Does the scan tool display all 4 tire pressures as specified? | LF Tire Pressere-10 psi, RF Tire Pressure-20 psi, RR Tire Pressure-30 psi, LR Tire Pressure-40 psi, +/- 4 psi | Go to Step 4 | Go to Step 7 | |
4 | Learn the tire pressure sensors. Refer to Tire Pressure Sensor Learn . Did you complete the procedure? | Go to Step 5 | -- | |
Operate the vehicle within the conditions for running and setting the DTC. Does the DTC reset? | Go to Step 6 | System OK | ||
6 | Replace the suspect sensor. Refer to Tire Pressure Indicator Sensor Replacement . Did you complete the replacement? | Go to Step 8 | - | |
7 | Replace the RCDLR. Refer to Remote Control Door Lock Receiver Replacement In Keyless Entry. Did you complete the replacement? | Go to Step 8 | - | |
8 |
does the DTC reset? | Go to Step 2 | System OK | |
