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Home >> Suzuki >> 1999 >> Grand Vitara JS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0101: Mass Airflow (MAF) Performance Problem >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Visually inspect for any obstructions or leaks in MAF sensor ducting. Repair as necessary. If visual inspection does not reveal any problems, turn ignition off. Connect scan tool to Data Link Connector (DLC). Start engine and allow it to reach normal operating temperature. Select MAF value parameter on scan tool. Increase engine speed to 2500 RPM. Display on scan tool should read 8.2-15.0 g/sec. Return engine to idle. Display on scan tool should read 2.5-4.6 g/sec. If reading is not as specified, go to step  5 . If reading is as specified, go to next step.
  2. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on. Using DVOM, measure voltage between ground and MAF sensor harness connector terminal No. 3 (Blue/Black wire). If 10-14 volts exists, go to next step. If 10-14 volts does not exist, repair open in Blue/Black wire. See WIRING DIAGRAMS article. Retest system.
  3. Reconnect MAF sensor harness connector. Remove PCM cover, located below right side of instrument panel. Connect DVOM (backprobe) between PCM 26-pin connector "B" terminals No. 20 (Gray/Yellow wire) and No. 23 (Violet/White wire). With ignition switch in RUN position, 0-.5 volt should exist. Start and idle engine. DVOM should display 1.0-1.5 volts. If readings are not as specified, go to next step. If readings are as specified, check for poor connection at PCM 26-pin connector "B" terminals No. 20 (Gray/Yellow wire) and No. 23 (Violet/White wire). Repair as necessary. If PCM connections are okay, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION article. Retest system.
  4. Check for open in Gray/Yellow wire or Violet/White wire between PCM and MAF sensor. See WIRING DIAGRAMS article. Repair as necessary. If wiring between PCM and MAF sensor is okay, replace MAF sensor. See REMOVAL, OVERHAUL & INSTALLATION article. Retest system.
  5. Connect DVOM (backprobe) between PCM 26-pin connector "B" terminals No. 13 (Red/White wire) and No. 20 (Gray/Yellow wire). With ignition switch in RUN position, 4.5-5.5 volts should exist. Start and idle engine. DVOM should display 1.5-2.5 volts. If readings are as specified, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION article. If readings are not as specified, a Manifold Differential Pressure (MDP) sensor problem exists. See DTC P1408: MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR CIRCUIT MALFUNCTION  .
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