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IGNITION TIMING CHECK
Required Special Tool:
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: V.C.I.
    • MB991827: M.U.T.-III USB Cable
    • MB991910: M.U.T.-III Main Harness A
1. Before inspection, set the vehicle in the following condition:
  • Engine coolant temperature: 80 - 95°C (176 - 203°F)
  • Lights and all accessories: OFF
  • Transaxle: P range
noteOn vehicles for Canada, the headlight, taillight, etc. remain lit even when the lighting switch is in "OFF" position but this is no problem for checks.
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
2. Connect scan tool MB991958 to the data link connector.
3. Set the timing light to the power supply line (terminal No. 3) of the ignition coil No. 1.
4. Start the engine and run it at idle.
5. Check that the idle speed is approximately 650 r/min.
6. Select scan tool MB991958 actuator test "item number 11".
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:
  • Diagnostic output
  • Timing chain cover and crankshaft position sensor installation conditions
  • Crankshaft sensing blade condition
cautionIf the actuator test is not canceled, the forced drive will continue for 27 minutes. Driving in this state could lead to engine failure.
9. Cancel the setting mode of the scan tool MB991958.
10. Check that the actual ignition timing is at the standard value.
Standard value: Approximately 10° BTDC
noteIgnition timing fluctuates about ± 7°, even under normal operating condition.
note It is automatically further advanced by about 5° from 10° Before Top Dead Center at higher altitudes.
noteWait till approximately 1 minute passes after the engine started, and check the ignition timing when the engine stabilized.
11. Remove the timing light.
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
12. Disconnect scan tool MB991958 from the data link connector.