Circuit Description

The PCM opens fuel injectors by grounding an injector driver circuit. PCM monitors voltage on each driver to detect a fault. If the voltage is not what the PCM expects to monitor, due to an injector driver being shorted to voltage for example, a DTC will be set.

Conditions required to set code are:

• Battery voltage is above 9 volts
• When injector is commanded off, injector voltage is not equal to ignition voltage.
• When injector is commanded on, injector voltage does not equal zero volts.
• Listed conditions met for 5 seconds. Diagnostic Aids An open or short in injector driver circuit will cause a DTC P0202 to set and a misfire to occur due to inoperative injector. This type of DTC will indicate which cylinder is inoperative. Long and short term fuel trims being excessively high or low are a good indication that an injector is faulty.