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Home >> Dodge and Ram >> 1988 >> Caravan Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> 3.0L CEC System >> Testing & Diagnosis >> Entering On-Board Diagnostics >> Diagnostic Test Mode

Diagnostic Test Mode

  1. The diagnostic test mode is used to determine if there are any fault codes stored in memory. Fault codes are 2-digit numbers that identify which circuit is bad.
  2. Start engine if possible. Cycle transaxle shift lever and A/C (if equipped). Turn engine off.
  3. To enter mode using DRB-II Tester (C-4805 ), set tester to "ENGINE OFF TEST". Turn ignition on, off, on, off, on within 5 seconds. Record all codes.
  4. If using "CHECK ENGINE" light to read codes, turn ignition on, off, on, off, on within 5 seconds. The "CHECK ENGINE" light will glow as a bulb test, then flash fault codes.
  5. For example code 23 is displayed as flash, flash, 4-second pause, flash, flash, flash. After a slightly longer pause, any other codes stored are displayed in numerical order. Once light begins to flash codes, it cannot be stopped. If you loose count, it is necessary to start over.
  6. The setting of a specific code is the result of a particular circuit failure. It does not identify the specific component in a circuit. The diagnostic system cannot determine the reason for a failure, only the fault is due to a particular circuit identified with that code.
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