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Variable Valve Timing Unit - Checking & Adjusting, Replacement (Convertible): Diagnosis Volvo C70 I

Mechanical ~403 words

The Volvo Scan Tool (ST) as a verification tool

Check the control module self diagnostic by using the Volvo Scan Tool (ST). Diagnostic Test Mode (DTM) contains a menu called Diagnostic test. This displays a status menu that shows whether certain engine control module (ECM) conditions have been fulfilled or not.

When verifying a repair check whether a TRIP has been completed or not.

TRIP = YES

  1. All diagnostic functions have been carried out at least once during the same journey.

TRIP = NO

  1. Not all diagnostic functions have been completed, a sub-menu displays those which have not been completed.

SUBSTITUTE TRIP

  1. The control module has not completed all diagnostic functions because diagnostic trouble codes (DTCs) have prevented other diagnoses.

Check all diagnostic functions as follows.

To complete a TRIP as fast as possible follow a special driving schedule.

  1. If the engine control module (ECM) has been without power the engine should be started a few times before the test is carried out.
  2. If the car has been without power and misfire-related diagnostic trouble codes (DTCs) are being verified a flywheel adaptation must be carried out before verification.
  3. The test should take place on a road with little traffic where it is possible to drive slowly and stop at the side of the road.
  4. The air conditioning (A/C) can be on when the engine is running at part load but must be switched off before the engine is idled.
  5. Engine coolant temperature (ECT) should not be above 25°C when the engine is started before the test.
  6. Ensure that there are no diagnostic trouble codes (DTCs) stored in the system before carrying out verification.
  7. Start the engine and drive according to the schedule, use the Diagnostic test menu in the Volvo Scan Tool (ST) to see when a TRIP has been completed.

Driving schedule

  1. Start engine.
  2. move gear selector to drive
  3. accelerate gently to 1.500 - 2.000 RPM
  4. drive for 5 minutes at 1.500 - 2.000 RPM
  5. idle engine for 70 seconds
  6. drive engaged, air conditioning (A/C) off
  7. drive for 6 minutes at 1.500 - 2.000 RPM
  8. idle engine for 40 seconds
  9. drive engaged
  10. air conditioning (A/C) off
  11. drive for 5 minutes at 1.500 - 2.000 RPM

Testing

Erase diagnostic trouble codes.

Test-drive car.

Check that no new diagnostic trouble codes are displayed.

If new codes are displayed, continue troubleshooting as per VIDA.

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