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Home >> Chevrolet >> 1997 >> C3500 HD 7.4 J, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 3 (Engine Controls - Tests W/Codes - 6.5L) >> Diagnostic Trouble Codes >> DTC P0102 - MAF Sensor Circuit Low Frequency >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 6.5L DIESEL article. Then go to next step.
  2. Start engine. With engine at idle, monitor MAF display on scan tool. If MAF reading is less than 1280 Hz, go to step 4). If MAF reading is greater than 1280 Hz, go to next step.
  3. Turn engine off. Turn ignition on, with engine off. Review and record Fail Records data on scan tool. Operate vehicle within the Fail Records conditions as noted. Using scan tool, monitor SPECIFIC DTC information for DTC P0102. If scan tool indicates that DTC P0102 failed in this ignition cycle, go to next step. If DTC P0102 did not fail in this ignition cycle, see DIAGNOSTIC AIDS.
  4. Check for blocked MAF sensor inlet, large intake manifold or EGR leaks, or large leaks downstream of MAF sensor. Repair as necessary. After repairs, go to step 14). If no problems are found, go to next step.
  5. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on, with engine off. Check voltage between MAF sensor harness connector terminal "A" (signal circuit) and ground. If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 9).
  6. Connect test light between MAF sensor harness connector terminal "C" (ignition feed) and ground. If test light illuminates, go to step 8). If test light does not illuminate, go to next step.
  7. Connect test light between MAF sensor harness connector terminal "C" and battery negative terminal. If test light illuminates, go to step 10). If test light does not illuminate, go to step 11).
  8. Check for poor connection at MAF sensor. Repair as necessary. After repairs, go to step 14). If connections are okay, go to step 12).
  9. Check circuit between MAF sensor PCM for an open, short to ground, short to MAF sensor ground circuit, or short to voltage. Repair as necessary. After repairs, go to step 14). If circuits are okay, go to step 13).
  10. Locate and repair open in ground circuit to MAF sensor. After repairs, go to step 14).
  11. Locate and repair open in ignition feed circuit to MAF sensor. After repairs, go to step 14).
  12. Replace MAF sensor. After replacing MAF sensor, go to step 14).
  13. Replace PCM. After replacing PCM, go to next step.
  14. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC number that was set. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2).
  15. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
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