DTC P0108: Map Sensor Volts Too High: Testing
- Turn ignition on. Using scan tool, read MAP sensor voltage. If voltage is more than 4.6 volts, go to next step. If voltage is 4.6 volts or less, go to step 8 .
- Turn ignition off. Disconnect MAP sensor harness connector. See Figure . Disconnect PCM harness connectors. PCM is located in engine compartment, between air cleaner and radiator. Measure resistance between 5-volt supply circuit (Violet/White wire) and signal circuit (Dark Green/Red wire) at MAP sensor harness connector. If resistance is 100 ohms or more, go to next step. If resistance is less than 100 ohms, repair short between 5-volt supply circuit and signal circuit.
- Reconnect PCM harness connectors. Turn ignition on. Measure voltage between ground and signal circuit (Dark Green/Red wire) at MAP sensor harness connector. If voltage 5.2 volts or less, go to next step. If voltage is more than 5.2 volts, repair short to battery voltage in signal circuit.
- Turn ignition off. Connect a jumper wire between signal circuit (Dark Green/Red wire) and sensor ground circuit (Black/Light Blue wire) at MAP sensor harness connector. Turn ignition on. Using scan tool, read MAP sensor voltage. If voltage is one volt or more, go to next step. If voltage is less than one volt, replace MAP sensor.
- Turn ignition off. Remove jumper wire. Disconnect PCM harness connectors. Measure resistance of signal circuit (Dark Green/Red wire) between MAP sensor harness connector and terminal No. 36 at PCM C1 harness connector. See Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in signal circuit.
- Measure resistance of sensor ground circuit (Black/Light Blue wire) between MAP sensor harness connector and terminal No. 43 at PCM C2 harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in sensor ground circuit.
- If no other possible causes are remaining, replace PCM.
- Conditions that set DTC are not present at this time. Perform the following to help identify intermittent condition:
- With engine running at normal operating temperature, wiggle related wiring harness while monitoring related parameters on scan tool. If voltage changes or DTC sets while wiggling wiring harness, repair connectors or wiring harness where wiggling caused voltage to change or DTC to set.
- Review freeze frame information on scan tool. Duplicate conditions present when DTC was set.
- Refer to any Technical Service Bulletins (TSBs) that may apply.
- Visually inspect related wiring harness. Check for chafed, pierced, pinched or partially broken wires.
- Visually inspect related wiring harness connectors. Check for broken, bent, pushed out or corroded terminals.
If a problem is found, repair as necessary. If no problems are found, test is complete.