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DTC B1487: Generator "L" Terminal Low With Engine Running: Testing

  1. If BFC diagnostic system check was performed, go to next step. If BFC diagnostic system check was not performed, see procedures in BFC DIAGNOSTIC SYSTEM CHECK  .
  2. Run engine for more than one minute. Using DVOM, check voltage by backprobing between generator harness connector terminal "B" (Red wire) and ground. If battery voltage exists, go to step 9). If battery voltage does not exist, go to next step.
  3. Disconnect generator connector. On 2.4L, disconnect PCM Blue 80-pin connector C1. On 3.1L, disconnect PCM Clear 80-pin connector C2. On all models, use DVOM to check resistance between generator harness connector terminal "B" (Red wire) and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 7).
  4. Reconnect all connectors and components. Run engine for more than one minute. Using DVOM, check voltage by backprobing between generator harness connector terminal "B" (Red wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 6).
  5. Using scan tool, read PCM "L" terminal input. If "L" terminal input is high, go to step 9). If "L" terminal is not high, go to step 8).
  6. Replace generator. See GENERATOR & REGULATOR article in ELECTRICAL. Go to step 9).
  7. Repair short to ground in Red wire between generator and PCM connector C1 (2.4L) or connector C2 (3.1L). Go to step 9).
  8. Replace PCM. See REMOVE/INSTALL/OVERHAUL article in ENGINE PERFORMANCE section. Go to next step.
  9. Clear DTCs. Perform BFC DIAGNOSTIC SYSTEM CHECK  .


  1. If BFC diagnostic system check was performed, go to next step. If BFC diagnostic system check was not performed, see procedures in BFC DIAGNOSTIC SYSTEM CHECK  .
  2. Run engine for more than one minute. Using DVOM, check voltage by backprobing between generator harness connector terminal "B" (Red wire) and ground. If battery voltage exists, go to step 9). If battery voltage does not exist, go to next step.
  3. Disconnect generator connector. On 2.4L, disconnect PCM Blue 80-pin connector C1. On 3.1L, disconnect PCM Clear 80-pin connector C2. On all models, use DVOM to check resistance between generator harness connector terminal "B" (Red wire) and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 7).
  4. Reconnect all connectors and components. Run engine for more than one minute. Using DVOM, check voltage by backprobing between generator harness connector terminal "B" (Red wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 6).
  5. Using scan tool, read PCM "L" terminal input. If "L" terminal input is high, go to step 9). If "L" terminal is not high, go to step 8).
  6. Replace generator. See GENERATOR & REGULATOR article in ELECTRICAL. Go to step 9).
  7. Repair short to ground in Red wire between generator and PCM connector C1 (2.4L) or connector C2 (3.1L). Go to step 9).
  8. Replace PCM. See REMOVE/INSTALL/OVERHAUL article in ENGINE PERFORMANCE section. Go to next step.
  9. Clear DTCs. Perform BFC DIAGNOSTIC SYSTEM CHECK  .
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