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Home >> Volvo >> 1995 >> 850 Base, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Turbo >> Diagnostic Trouble Code Testing >> MOTRONIC 4.3 Control System >> Code 5-4-1: EVAP Signal

Code 5-4-1: EVAP Signal

  1. Check status message on Volvo Scan Tool (998-8686 ). If fault is permanent and signal is too high, go to step 2). If fault is PERMANENT, SIGNAL TOO LOW, go to step 3). If fault is INTERMITTENT, SIGNAL TOO HIGH, go to step 7). If fault is INTERMITTENT, SIGNAL TOO LOW, go to step 8).
  2. Turn ignition off. Disconnect EVAP valve. Connect ohmmeter between EVAP valve connector terminals No. 1 and 2. If ohmmeter reads about 26 ohms, check wiring between EVAP valve connector terminal No. 2 and ECM terminal A39 for a short circuit to voltage. If ohmmeter does not read 26 ohms, retest using new EVAP valve.
  3. Turn ignition off. Disconnect EVAP valve. Turn ignition on. Connect voltmeter between EVAP valve connector, terminal No. 1, and ground. If voltmeter reads battery voltage, go to next step. If voltmeter does not read battery voltage, check wiring between EVAP valve connector terminal No. 1 and main relay connector terminal No. 3 for an open circuit.
  4. Turn ignition off. Wait about 2 seconds. Disconnect EVAP valve. Connect ohmmeter between EVAP valve connector terminal No. 2 and ground. If ohmmeter reads 25-40 k/ohms, go to next step. If ohmmeter reads infinite resistance, go to step 6). If ohmmeter reads about zero ohms, check wiring between EVAP valve connector terminal No. 2 and ECM terminal A39 for a short circuit to ground.
  5. Turn ignition off. Disconnect EVAP valve connector. Connect ohmmeter between EVAP valve connector terminals No. 1 and 2. If ohmmeter reads about 26 ohms, code is caused by poor contact in EVAP and/or ECM connector. Repair as necessary. If ohmmeter does not read about 26 ohms, retest using new EVAP valve.
  6. Turn ignition off. Disconnect EVAP valve connector. Disconnect ECM. Ensure ECM connector terminals are clean and make good terminal contact. Repair as necessary. Connect ohmmeter between EVAP valve connector terminal No. 2 and ground. If ohmmeter reads 25-40 k/ohms, code is caused by poor contact at ECM connector. If ohmmeter does not read 25-40 k/ohms, check wiring between EVAP valve connector terminal No. 2 and ECM terminal A39 for an open circuit.
  7. If fault is intermittent and signal is too high, check wiring between EVAP valve connector terminal No. 2 and ECM terminal A39 for an intermittent short circuit to voltage. Repair as necessary.
  8. If fault is intermittent and signal is too low, check EVAP valve and ECM connector for loose connection or contact resistance. Check wiring between EVAP valve connector terminal No. 1 and main relay connector terminal No. 3 for an intermittent open circuit. Also check wiring between EVAP valve connector terminal No. 2 and ECM terminal A39 for an intermittent open circuit or short circuit to ground.
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