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

Code 5-1-4: Engine Cooling Fan Half Speed

  1. Using Volvo Scan Tool (998-8686 ), read off status message. If PERMANENT FAULT, SIGNAL TOO HIGH is displayed, go to next step. If PERMANENT FAULT, SIGNAL TOO LOW is displayed, go to step 3). If INTERMITTENT FAULT, SIGNAL TOO HIGH is displayed, go to step 8). If INTERMITTENT FAULT, SIGNAL TOO LOW is displayed, go to step 9).
  2. If PERMANENT FAULT, SIGNAL TOO HIGH is displayed, turn ignition off. Disconnect connector "B" from Fuel Control (FC) relay. Turn ignition on. Connect voltmeter between FC relay connector "B", terminal No. 1, and ground. If voltmeter reads about zero volts, retest using new FC relay. If voltmeter does not read about zero volts, check wiring between FC relay connector "B", terminal No. 1, and ECM terminal A7 for a short circuit to voltage.
  3. IF PERMANENT FAULT, SIGNAL TOO LOW is displayed, turn ignition off. Disconnect connector "A" from Fuel Control (FC) relay. Connect voltmeter between FC relay connector "A" and ground. If voltmeter reads battery voltage, go to next step. If voltmeter does not read battery voltage, check fusible link in wiring between starter motor and FC relay. Check relay and fan motor before replacing fusible link.
  4. Turn ignition off. Disconnect connectors "A" and "B" from FC relay. Connect an ohmmeter between FC relay connector "B", terminal No. 1, and ground. If ohmmeter reads 28-38 k/ohms, go to step 6). If ohmmeter reads about zero ohms, check wiring between FC relay connector "B", terminal No. 1, and ECM terminal A7 for a short circuit to ground. If ohmmeter reads infinite resistance, go to next step.
  5. Turn ignition off. Disconnect FC relay connectors "A" and "B". Ensure all terminal connectors are clean and tight. Reconnect connectors. Connect an ohmmeter between FC relay connector "B", terminal No. 1, and ground. If ohmmeter reads 28-38 k/ohms, go to step 7). If ohmmeter does not read 28-38 k/ohms, check wiring between FC relay connector "B", terminal No. 1, and ECM terminal A7 for an open circuit.
  6. Turn ignition off. Disconnect connectors "A" and "B" from FC relay. Connect an ohmmeter between FC relay connector "B", terminal No. 2, and ground. If ohmmeter reads infinite resistance, go to next step. If ohmmeter does not read infinite resistance, check wiring between FC relay connector "B", terminal No. 2, and ECM terminal A22 for a short circuit to ground.
  7. Turn ignition off. Ensure connectors "A" and "B" are connected to FC relay. Start engine and run at idle. Using Volvo Scan Tool (998-8686 ), read off status message. If status message is PERMANENT, SIGNAL TOO LOW, retest using new FC relay. If status message is intermittent, source of code is poor contact in FC relay and/or ECM connector. Ensure connector terminals are clean and free of oxidation.
  8. If fault is intermittent and signal is too high, check wiring between FC relay connector "B", terminal No. 1 , and ECM terminal A7 for an intermittent short circuit to voltage.
  9. If fault is intermittent and signal is too low, check FC relay and ECM connectors for loose connection or poor terminal contact. Check wiring between FC relay connector "B", terminal No. 1, and ECM terminal A7 for signs of an intermittent open or short circuit to ground. Also check wiring between FC relay connector "A", terminal No. 1, and starter motor for an intermittent open circuit.
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