Intermittent failures in electronic systems may be very
difficult to detect and accurately diagnose. The Tire Pressure Monitor (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:
• | Poor mating of connector halves or backed out terminals |
• | Improperly formed or damaged terminals |
• | Poor wire to terminal connections |
• | Dirty or corroded terminals |
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 TPM sensors are
reliable components, and are not likely the 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:
• | Any condition which results in the interruption of power to the
receiver |
• | The battery or ignition voltage is out of range (below 9.0 volts
or above 16.0 volts). |
• | A loose or damaged ground |
• | Radio frequency interference |
• | An open or a short on the serial data line |