Testing Notes

NOTE: You should enter this Pinpoint Test only when you have been directed here from Quick Test.


REMEMBER

To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault.

^ Vehicle Speed Control system

^ Rear Anti-Lock Brake system

^ Instrumentation system



This Pinpoint Test is intended to diagnose only the following:


^ PSOM output to the processor

^ Harness circuits: PSOM(+), PSOM(-)

^ Processor assembly


DESCRIPTION


The Programmable Speedometer/Odometer (PSOM) receives inputs from the Rear Anti-Lock Brake System (RABS) Speed Sensor, which is mounted on the rear axle differential. The PSOM takes the input signal information to the Speed Control module and the EEC-IV processor.