Circuit Description
WARNING: This page is about a different variant/trim than selected.
Optical sensor provides a pump cam signal to PCM by counting pulses on sensor disk located in injection pump. Pump cam is an important input by PCM for fuel control and timing. Test monitors number of crankshaft position pulses that have occurred since last cam pulse. Physical one to one correspondence between pump cam and crankshaft implies more crank pulses are missed.
DTC will set when the following conditions are present:
- Eight consecutive cam pulses missing.
Or
- An average of 8 cam pulses missing.