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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 117 (Engine Controls - Self-Diagnostics - 3.0L) >> Diagnostic Tests >> DTC P0102: MAF Sensor Circuit - Low Signal/Frequency >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition on, with engine off. Using scan tool, monitor MAF sensor. If voltage reading is less than 0.20 volt, go to next step. If voltage reading is not less than 0.20 volt, problem is intermittent. See DIAGNOSTIC AIDS  .
  2. Turn ignition on, engine off. Check EMISS fuse (10-amp) located in underhood fuse block. Replace as necessary. If fuse continues to open, repair short to ground in White wire. Disconnect MAF sensor harness connector. MAF sensor is located on air cleaner assembly. Using a DVOM, measure voltage at MAF sensor harness connector terminal No. 4 (Black wire). If voltage reading is 4-6 volts, go to next step. If voltage reading is not 4-6 volts, go to step  5 .
  3. Using a jumper wire, jumper MAF sensor harness connector terminals No. 4 (Black wire) and No. 5 (Yellow wire). Using scan tool, monitor MAF sensor. If voltage reading is more than 4.8 volts, go to next step. If voltage reading is not more than 4.8 volts, go to step  6 .
  4. Connect a test light between ground and MAF sensor harness connector terminal No. 2 (White wire). If test light does not illuminate, check for open in circuit between MAF sensor and underhood fuse block. If test light illuminates, check connectors. Repair as necessary. If connectors are okay, replace MAF sensor.
  5. Using scan tool, monitor MAP sensor, APP sensor 1 and FTP sensor. If all 3 readings are below 0.2 volt, repair short to ground in 5-volt reference "A" circuit (Tan wire). If all 3 readings are not below 0.2 volt, repair open in Tan wire between MAF and ECM.
  6. Turn ignition off. Disconnect ECM harness connector J1. Check for continuity between ground and MAF sensor harness connector terminal No. 5 (Yellow wire). Check for continuity between MAF sensor harness connector terminals No. 3 (Black wire) and No. 5 (Yellow wire). If continuity exists on these circuits, go to next step. If continuity does not exist on these circuits, go to step  8 .
  7. Check for short to ground in Yellow wire between MAF sensor and ECM. Check for short between MAF sensor harness connector terminals No. 5 (Yellow wire) and No. 3 (Black wire) circuits. Repair as necessary.
  8. Check for open in Yellow wire between MAF sensor and ECM. Repair as necessary. If circuit is okay, check connectors. Repair as necessary. If connectors are okay, replace ECM.
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