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Powertrain Control System Diagnostic System Check

NOTE: Malfunction Indicator Light (MIL) may also be referred to as SERVICE ENGINE SOON light.
  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). DLC is located below left side of instrument panel, to right of steering column. See Figure . Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST G: SCAN TOOL DOES NOT POWER UP  under SYSTEM TESTS.
  2. Try to establish scan tool communication with all modules. If communication with all modules is established, go to next step. If communication with all modules is not established, go to TEST F: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  3. Attempt to start and idle engine. If engine starts and idles, go to next step. If engine does not start and idle, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE.
  4. Select DISPLAY DTC function for each module. Record all displayed DTCs and status of displayed DTCs. If any DTCs are displayed, go to next step. If no DTCs are displayed, go to step  9 .
  5. Using scan tool, select CAPTURED INFO function to store PCM DTC information. After storing PCM DTC information, go to next step.
  6. If scan tool does not display any DTCs that begin with "U", go to next step. If scan tool displays any DTCs that begin with "U", go to TEST F: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  7. If scan tool does not display DTCs P0601 or P0602, go to next step. If scan tool displays DTCs P0601 or P0602, perform appropriate test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  8. If scan tool displays DTCs P0560 or P0620, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTCs P0560 or P0620, perform appropriate test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  9. If customer's concern is not transmission-related, go to next step. If customer's concern is transmission-related, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS or MANUAL TRANSMISSIONS.
  10. If customer's concern is not Inspection/Maintenance (I/M) testing-related, go to next step. If customer's concern is I/M testing-related, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE.
  11. If customer's concern is hard start surges, lack of power, sluggishness, sponginess, detonation/spark knock hesitation, sag, stumble, cuts out, misses poor fuel economy, poor fuel fill quality, rough idle, unstable idle, incorrect idle, stalling, dieseling, run-on, backfire, MIL always on or MIL inoperative, repair by symptom. See appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE. If no symptoms are present, system is okay.
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