Circuit Description
The tire pressure monitor (TPM) system has 4 radio frequency (RF) transmitting pressure sensors in each wheel/tire assembly. As vehicle speed increases above 32 km/h (20 mph) the sensors internal roll switch closes which puts the sensor into drive mode. In this mode the sensors begin to transmit once every 60 seconds to the remote control door lock receiver (RCDLR). The data within this RF transmission is translated by the RCDLR into sensor presence, sensor mode, and tire pressure. The RCDLR waits for the first sensor to go into drive mode then checks if all sensors have gone into drive mode.
Conditions for Running the DTC
Vehicle speed is above 32 km/h (20 mph) for 35 minutes
Conditions for Setting the DTC
Any given sensor does not go into drive mode, or does not transmit at all for 15 minutes.
Action Taken When the DTC Sets
| • | A DTC is stored in memory |
| • | The DIC displays the SERVICE TPM SYSTEM 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. |
| • | Use a scan tool. |
Diagnostic Aids
| • | A newly replaced RCDLR will set DTC C2121 upon the first ignition ON cycle. If this DTC is set, refer to Tire Pressure Sensor Learn . |
| • | Loss of, or low system battery voltage will cause all of the sensor Id codes to be erased from the RCDLRs memory and set DTC C2120. If this DTC is set, or this condition is suspected, refer to Tire Pressure Sensor Learn . |
| • | If the vehicle is stationary for more than 15 minutes after being driven the sensors will go into stationary mode. Always test drive the vehicle above 32 km/h (20 mph) to ensure the sensors are in drive mode before viewing tire pressures on the DIC. |
| • | If there is an open in the serial data circuit to the receiver, the DIC will display dashes for all tire pressures and the SERVICE TPM SYSTEM message. |
| • | Occasionally sensor transmission will not be 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 malfunction is system, or vehicle condition related.
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Tests if the sensors internal roll switch is functioning properly.
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Tests if the malfunction was corrected by sensor replacement, or if the malfunction still exists in the RCDLR.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Tire Pressure Monitoring System Schematics | |||
1 | Did you perform the TPM Diagnostic System Check? | Go to Step 2 | |
Does the scan tool indicate that DTC C2100, C2105, C2110, C2115, or C2120 is current? | Go to Step 3 | Go to Diagnostic Aids | |
3 | Since some occurrences of this DTC are caused by certain vehicle conditions, review the TPM system with the customer to verify the conditions under which the DTC set. Did vehicle conditions cause the DTC to set? | Go to Diagnostic Aids | Go to Step 4 |
4 | learn the tire pressure sensors. Refer to Tire Pressure Sensor Learn . Did a horn chirp sound when learning the suspect sensor? | Go to Step 5 | Go to Step 6 |
Does the DTC reset? | Go to Step 6 | System OK | |
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 8 | Go to Step 7 | |
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 |
