Low Tire Pressure Indicator

The Tire Pressure Monitor (TPM) indicator gives an indication to the vehicle operator of the status of the TPM system. The TPM indicator is controlled by the CCN circuit board based upon programming and electronic messages received from the Wireless Control Module (WCM) over the CAN data bus. The CCN will illuminate the TPM indicator for about three seconds each time the ignition is turned to the ON position, during the bulb test

The TPM indicator is completely controlled by the CCN logic circuit, that logic only allow's this indicator to operate when the CCN receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the indicator will always be OFF when the ignition switch is in any position except ON or START. The indicator only illuminates when it is energized by the instrument cluster logic circuit. The CCN will illuminate the TPM indicator for the following reasons:

• TPM Indicator Lamp-On Message  - Each time the cluster receives an electronic TPM indicator lamp-ON  message from the SKREEM, the TPM indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the SKREEM message. The indicator remains illuminated until the cluster receives a lamp-OFF message from the SKREEM, or until the ignition switch is turned to the OFF position, whichever occurs first.
• Premium Cluster TPM Pressure Indication  - On vehicles equipped with the optional premium cluster with a reconfigurable VFD, an icon representing an overhead view of the vehicle is displayed in the reconfigurable VFD with the actual monitored pressure of each tire.
• Communication Error  - If the cluster receives no TPM lamp-ON or lamp-OFF messages from the SKREEM for six consecutive seconds, the TPM indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid lamp-ON or lamp-OFF message is received from the SKREEM.

The SKREEM performs a self-test each time the ignition switch is turned to the ON position to decide whether the TPM system is in good operating condition and whether the tire inflation pressures are too high or too low. The SKREEM then sends the proper lamp-ON or lamp-OFF message to the CCN. If the instrument cluster turns ON the TPM indicator after the bulb test, it indicates that the inflation pressure of a tire is too low or that a malfunction has occurred and the TPM system is ineffective.