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Home >> Jaguar >> 2000 >> XJ8 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Trouble Code Identification >> DTC P0101: Mass Airflow Sensor Performance >> Diagnostic Test Procedure
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Diagnostic Test Procedure

NOTE: MAF sensor is also a possible cause of DTCs P0171 and P0174. Before performing this procedure, check the air filter for blockage, the engine air intake and breather systems for leaks, and the Throttle Position Sensor (TPS) for additional DTCs.
  1. Disconnect negative battery cable. Disconnect the ECM connector EM83. Disconnect the MAF sensor connector. Measure resistance between EM83 harness connector terminal No. 28 and MAF sensor harness connector terminal No. 3. Is resistance greater than 5 ohms? If yes, repair wiring as necessary. If no, go to next step.
  2. Reconnect negative battery cable. Turn ignition on. Measure voltage between the MAF sensor harness connector terminal No. 3 and ground. Is voltage greater than 3 volts? If yes, repair short to voltage. If no, go to next step.
  3. Turn ignition off. Measure resistance between MAF sensor harness connector terminal No. 3 and ground. Is resistance less than 10,000 ohms? If yes, repair short to ground. If no, go to next step.
  4. Reconnect ECM connector EM83. Turn ignition on. Measure voltage between MAF sensor harness connector terminal No. 1 and ground. Is voltage greater than 10 volts? If yes, go to next step. If no, repair wiring between MAF sensor harness connector terminal No. 1 and battery, as necessary. This circuit includes the EMS control relay, the EMS fuse box (fuse No. 12), and splices in the harness.
  5. Disconnect negative battery cable. Disconnect the EMS fuse box connector EM20. Measure resistance between EMS fuse box harness connector EM20 terminal No. 10 and MAF sensor harness connector terminal No. 1. Is resistance greater than 5 ohms? If yes, repair wiring as necessary. If no, go to next step.
  6. Reconnect negative battery cable. Measure resistance between EMS fuse box harness connector EM20 terminal No. 10 and ground. Is resistance less than 10,000 ohms? If yes, repair short to ground. If no, install a new MAF sensor. See MASS AIRFLOW (MAF) SENSOR under ENGINE SENORS in REMOVAL, OVERHAUL & INSTALLATION article.
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