Test Step 6 - Sensor Ground Circuit High Resistance
- Turn the ignition off.
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.
- Using a voltmeter, perform a voltage drop test by backprobing the sensor ground circuit at the MAP sensor harness connector and by probing the appropriate terminal of the special tool #8815. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
- Start the engine.
Is the voltage less than 0.5 volts?
Yes
- Go to Test Step TEST STEP 7 - MAP SENSOR .
No
- Repair the sensor ground circuit for excessive resistance.
- Perform the PCM Verification Test. Refer to PCM VERIFICATION TEST .