P0108
P0108 - Manifold Absolute Pressure Sensor Circuit High
For wiring diagrams, refer to.
• When Monitored: With the engine running and battery voltage greater than 10 volts.
• Set Condition: The PCM detects that the sensor input voltage is more than the maximum acceptable value.
• Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - DTC is Active
• Start the engine and allow it to reach normal operating temperature.
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.
• Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
• With the scan tool, select view DTCs.
Is the status active for this DTC?
Yes
• Go to Test Step 2 => [ Test
Step 2 - 5 Volt Supply Circuit Shorted to Voltage ]
No
• Refer to the checking for an intermittent DTC diagnostic procedure. Refer => Non-DTC Based Diagnostics.
Test Step 2 - 5 Volt Supply Circuit Shorted to Voltage
• Turn the ignition OFF.
• Disconnect the MAP sensor connector.
• Disconnect the PCM connector.
• Turn the ignition ON.
• Measure the voltage of the 5 volt supply circuit in the MAP sensor harness connector.
Is there any voltage present?
Yes
• Repair the 5 volt supply circuit for a short to voltage.
• Perform the PCM Verification Test. => Non-DTC Based Diagnostics. PCM Verification Test
No
• Go to Test Step 3 => [ Test
Step 3 - MAP Signal Circuit Shorted to Voltage ]
Test Step 3 - MAP Signal Circuit Shorted to Voltage
• Measure the voltage of the MAP signal circuit in the MAP sensor harness connector.
Is there any voltage present?
Yes
• Repair the MAP signal circuit for a short to voltage.
• Perform the PCM Verification Test. => Non-DTC Based Diagnostics. PCM Verification Test
No
• Go to Test Step 4 => [ Test
Step 4 - MAP Signal Circuit Shorted to the 5 Volt Supply Circuit ]
Test Step 4 - MAP Signal Circuit Shorted to the 5 Volt Supply Circuit
• Turn the ignition OFF.
• Measure the resistance between the MAP signal circuit and the 5 volt supply in the MAP sensor harness connector.
Is the resistance less than 100 ohms?
Yes
• Repair the MAP signal circuit for a short to the 5 volt supply circuit.
• Perform the PCM Verification Test. => Non-DTC Based Diagnostics. PCM Verification Test
No
• Go to Test Step 5 => [ Test
Step 5 - MAP Signal Circuit Open or High Resistance ]
Test Step 5 - MAP Signal Circuit Open or High Resistance
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 to perform diagnosis.
• Measure the resistance of the MAP signal circuit between the MAP sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 6 => [ Test
Step 6 - Sensor Ground Circuit Open or High Resistance ]
No
• Repair the MAP signal for an open circuit or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 6 - Sensor Ground Circuit Open or High Resistance
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 to perform diagnosis.
• Measure the resistance of the sensor ground circuit between the MAP sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 7 => [ Test
Step 7 - MAP Sensor Voltage ]
No
• Repair the sensor ground circuit for an open or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 7 - MAP Sensor Voltage
• Turn the ignition OFF.
• Connect the PCM connector.
• Connect a jumper wire between the sensor ground circuit and the MAP signal circuit in the MAP sensor harness connector.
• Turn the ignition ON.
• With the scan tool, read the MAP sensor signal voltage.
• The voltage should be approximately 0.0 volts (plus or minus 0.1 volt) with the jumper wire in place.
Does the scan tool display the voltage as described?
Yes
• Go to Test Step 8 => [ Test
Step 8 - MAP Sensor ]
No
• Go to Test Step 9 => [ Test
Step 9 - PCM ]
Test Step 8 - MAP Sensor
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP sensor and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
• Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
• Look for the data to change or for the DTC to reset during the wiggle test.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. => Non-DTC Based Diagnostics. PCM Verification Test
Test Step 9 - PCM
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP sensor and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
• Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
• Look for the data to change or for the DTC to reset during the wiggle test.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test