Intermittent failures in electronic systems may be very difficult to detect and accurately diagnose. The TPM system tests for different malfunctions under different vehicle conditions. For this reason, a thorough test drive is often needed in order to repeat a fault condition. If the system malfunction is not repeated during the test drive, a good description of the complaint may be useful in locating an intermitting fault condition. Faulty wires or connections cause most intermitting problems. When an intermitting condition is suspected, inspect the suspected circuits for the following conditions:

History DTCs are those indicating that the TPM system has previously detected a malfunction. The reason could be either that the malfunction is intermittent or that the conditions for setting the DTC are not met, try clearing the DTCs and manually operating the system that the DTC applies to. Read the Diagnostic Aids and Conditions for Setting the DTC in each DTC table for more specific information.

History DTCs help in diagnosing intermittent fault conditions but do not necessarily indicate a faulty receiver. The receiver and transmitters are reliable components, and is not the likely cause of the malfunction. Most system complaints are linked to faulty wiring and connectors, and occasionally to a component. Perform a thorough inspection of all related wiring and connectors pertaining to the history DTC that is stored.

The following conditions may result in intermittent TPM operation with no DTC stored: