Circuit/System Testing
- Inspect for the following conditions:
- An engine vacuum leak
- An air leak in the intake air duct between the mass air flow (MAF) sensor and the throttle body
- A plugged or collapsed intake air duct
- Objects that block the MAF sensor air inlet
- An air filter element that is restricted
- The hydro-carbon absorber in the air cleaner assembly for ruptures or deterioration.
- A restricted throttle plate or for carbon build-up around the throttle plate
- An unseated engine oil dip stick
- A loose or missing engine oil fill cap
- An over filled crankcase
- If you find any of the above conditions, repair as necessary.
- Ignition OFF, disconnect the harness connector at the MAF sensor.CAUTION: Do NOT use the low reference circuit in the component harness connector for this test. Damage to the control module may occur due to excessive current draw.
- Ignition ON, load test the ignition circuit for B+ between terminal B and ground.
- If less than the specified value, repair the ignition circuit for an open/high resistance.
- Test for less than 5 ohms between the ground circuit terminal C and the battery ground.
- If greater than the specified value, repair the ground circuit for an open/high resistance.
- Test for less than 5.10 volts between the signal circuit terminal A and ground circuit terminal C.
- If greater than the specified value, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
- Test for greater than 3.98 mA between the signal circuit terminal A and the ground circuit terminal C.
- If less than the specified value, test the signal circuit for an open/high resistance or for a short to ground. If the circuit/connections test normal, replace the ECM.
- If all circuits/connections test normal, replace the MAF sensor.