Ignition Timing: Testing and Inspection
- IGNITION TIMING CHECKRequired Special Tool MB991502: Scan Tool (MUT-II)
1. Before inspection, set vehicles in the following condition:
- Engine coolant temperature: 80 - 95°C (176 - 203°F)
- Lights and all accessories: OFF
- Transmission: P range
2. Connect scan tool MB991502 to the data link connector.
3. Set up a timing light.
4. Start the engine and run at idle.
5. Check that the idle speed is approximately 700 r/min.
6. Select scan tool MB991502 actuator test item number 17.
7. Check that basic ignition timing is within the standard value.
Standard value: 5° BTDC ± 3°
8. If the basic ignition timing is not within the standard value, check the following items:
- Diagnosis output
- Timing belt cover and crankshaft position sensor installation conditions
- Crankshaft sensing blade condition
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.
9. Press the clear key on scan tool MB991502 (select forced drive stop mode), and cancel the actuator test.
10. Check that the actual ignition timing is at the standard value.
Standard value: Approximately 15° BTDC
NOTE: Ignition timing fluctuates within about ± 7° Before Top Dead Center even under normal operating condition.
NOTE: It is automatically further advanced about 5° to 15° Before Top Dead Center at higher altitudes.