Diagnostic Procedures
- Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
- If DTC P0300 is also present, diagnose this DTC first. If DTC P0300 is not present, go to next step.
- Connect scan tool. Turn ignition on, with engine off. Using scan tool, select ENGINE 1 function and note MAP display value. If MAP value is greater than 75 kPa (95 kPa at sea level), go to next step. If MAP value is less than specification, go to step 7).
- Disconnect vacuum hose at MAP sensor. Connect a hand-held vacuum pump to MAP sensor. Slowly apply 20 in. Hg to sensor and note MAP display. Each one in. Hg applied to MAP sensor should result in a 4 kPa drop in MAP sensor reading. Watch for erratic reading. If reading is erratic, go to step 7). If reading changes smoothly, go to next step.
- If MAP sensor reading is 34 kPa or less with 20 in. Hg applied to sensor, go to next step. If MAP sensor reading is greater than 34 kPa with 20 in. Hg applied, go to step 7).
- Remove vacuum from MAP sensor. If MAP sensor reading returns to original value, see DIAGNOSTIC AIDS. If MAP sensor reading does not return to original value, go to next step.
- Replace MAP sensor.