Diagnostic Aids
- The following conditions may result in intermittent operation of IPC with no DTC stored:
- Any condition which results in interruption of power to IPC.
- Out of range battery or ignition voltage (normal IPC operating voltage is 9-16 volts).
- Loose or damaged ground(s).
- Open or shorted serial data line.
- IPC tests for different malfunctions during different vehicle conditions. A thorough test drive may be necessary to repeat malfunction. Most intermittent problems are caused by faulty electrical connections or wiring. Check for: poor connections, backed-out terminals, dirty or corroded terminals, chafed wires, or damaged connectors.
- If IPC loses battery power when ignition is on, IPC will display "AAAAAAA" in message display center. To prevent or clear this message, disconnect battery with ignition off.
- If IPC displays any history communication DTCs (letter "U" as a prefix), clear these DTCs first and recheck for codes before performing any further diagnosis of IPC. These DTCs may set under various conditions, and do not necessarily indicate a problem in IPC. If IPC cannot communicate properly on serial data line, IPC will display a combination of the following messages:
- SERVICE VEHICLE SOON
- SERVICE TIRE MONITOR
- ENGINE PROTECTED REDUCE ENGINE RPM
- LOW FUEL
- LOW TIRE PRESSURE