Power Solutions International, Inc.

8904

UnclassifiedGeneral

What This Code Means

Malfunction Indicator Light (MIL) ON during active fault; Closed Loop Disabled

Possible Causes

  • •Engine related problem
  • •Fuel system related problem
  • •Power is noisy due to a failed alternator
  • •Supply voltage problem where the ECM is unable to monitor noise via the low-passed supply feedback
  • •UEGO internal supply voltage is low
  • •UEGO processing circuitry supply voltage is too low for normal operation while Vbat or Vrelay low-pass filtered voltage is > 9.0V

Suggested Actions

  1. 1Inspect alternator and repair/replace as needed
  2. 2Perform OBD system check
  3. 3Replace ECM and re-test
  4. 4Replace UEGO sensor and re-test
  5. 5Troubleshoot supply voltage source and repair/replace as needed
  6. 6Verify the operation of the MIL

Related Power Solutions International, Inc. Fault Codes

8910891489028916890189203032520240:33031DTC - 3592229DTC - 520
Browse all Power Solutions International, Inc. fault codes

ASK RUDY ABOUT THIS FAULT

Get a diagnosis walkthrough for 8904 on your specific Power Solutions International, Inc. unit — cited to the OEM manual, not a forum guess.

GET THE ANSWER

Free account required — we'll bring your question with you.