System Description

The Electronic Control Unit (ECU) sets and stores "fault codes" if operating conditions of sensors or circuits are detected outside of programmed limits. Fault codes can be ``read'' from the memory, using a voltmeter. Fault codes are stored in computer memory with memory power supplied directly from the battery. Therefore fault codes remain in memory with the ignition key OFF. Fault codes can be erased by disconnecting the negative battery cable.
There are 16 fault codes including one for a normal state reading, that can be stored in memory.