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C70, S70 & V70

  1. Determine if fault is fuel or ignition. Check fuel pressure. See FUEL PRESSURE  under FUEL SYSTEM. If fuel pressure is not as specified, repair fuel system as necessary. If fuel pressure is as specified, fuel system is okay. Go to next step.
  2. Using a high output spark tester, check for spark at end of one spark plug wire. If spark is not present, go to next step. If spark is present, remove and inspect all spark plugs. Replace spark plugs as necessary. Try to start engine. If engine starts, fault was due to spark plugs. If engine does not start, check for defective mass airflow sensor or engine coolant temperature sensor. See K - SENSOR OPERATING RANGE CHARTS article.
  3. Turn ignition on. Select scrolling values on scan tool. Operate starter motor. Read off RPM. If RPM is 100-300 RPM during cranking, go to next step. If RPM is not 100-300 RPM, see ENGINE SPEED (RPM) SENSOR RESISTANCE table in K - SENSOR OPERATING RANGE CHARTS article.
  4. Turn ignition off. Disconnect Ignition Discharge Module (IDM) connector. Turn ignition on. Connect voltmeter between IDM connector terminal No. 3 and ground. See Fig 1. If battery voltage is present, go to next step. If battery voltage is not present, check fuse No. 4. Replace if necessary. If fuse is okay, check voltage supply to fuse.
  5. Ensure ignition is off. Wait about 2 minutes. Disconnect IDM module connector. Connect ohmmeter between IDM connector terminal No. 1 and ground. See Fig 1. If about zero ohms are present, go to next step. If about zero ohms are not present, check IDM connector ground terminal for poor terminal contact. Repair as necessary. Repeat test. If zero ohms are still not present, check for open circuit in wiring between IDM terminal No. 1 and ground.
  6. Turn ignition on. Disconnect IDM module connector. Connect multimeter between IDM module connector terminal No. 4 and ground. See Fig 1. Set multimeter to measure frequency. Operate starter motor. If frequency is 8-10 Hz when engine is cranked, go to step 9). If frequency is not 8-10 Hz when engine is cranked, go to next step.
  7. Connect voltmeter between IDM connector terminal No. 4 and ground. See Fig 1. If voltmeter reads 0-1 volt, go to next step. If voltmeter does not read 0-1 volt, check for short circuit to voltage in wiring between IDM terminal No. 4 and ECM terminal B11.
  8. Turn ignition off. Wait about 2 minutes. Disconnect IDM module and ECM connectors. Connect ohmmeter between ground and IDM connector terminal No. 4. See Fig 1. If infinite resistance is present, check for open circuit in wiring between IDM terminal No. 4 and ECM terminal B11. If infinite resistance is not present, check for short circuit to ground in wire between IDM terminal No. 4 and ECM terminal B11.
  9. Turn ignition off. Reconnect IDM module connector. Turn ignition on. Disconnect ignition coil wire from distributor cap. Hold end of wire about 1/4 inch from ground. Operate starter motor. If a spark occurs, check rotor, distributor cap, and spark plugs. Replace as necessary. If a spark does not occur, replace IDM.
Fig 1: Identifying IDM/Ignition Coil Connector Terminals (C70, S70 & V70)
G94C46054Courtesy of VOLVO CARS OF NORTH AMERICA.
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