Before servicing the vehicle, refer to the precautions in the beginning
of this section.
Before attempting to adjust the ignition timing, be sure of the following:
- The engine should be at normal operating temperature.
- The lights and all accessories should be OFF.
- If equipped with an automatic transmission, the transmission should
be in P or N.
- Connect scan tool MB991502 to the data link connector
- Set up the timing light.
- Start the engine and run at idle.
- Verify that the idle speed is 600–800 rpm.
- Select scan tool MB991502 actuator test "item number 17."
- Check that basic timing is with in standard, it should be 3–7°BTDC.
- Press the clear key on the scan tool, select forced drive stop mode
and cancel the actuator test.
CAUTION
If the actuator test is not canceled, the forced drive will continue for
27 minutes. Driving in this state could lead to engine failure.