Connect MUT-II Scan Tool (MB991502) to OBD-II Data Link Connector (OBD-II DLC) located below instrument panel. Start and idle engine. Ensure engine is warmed up, lights, accessories and cooling fan are off, and transmission is in Park or Neutral.
Using scan tool or tachometer, check that curb idle speed is within specifications. See IGNITION TIMING SPECIFICATIONS .
Using scan tool, select actuator test No. 17 (base ignition timing). Compare timing with standard base value.

NOTE: If base ignition timing actuator test is not cancelled, force-activation will continue for 27 minutes. DO NOT drive vehicle in this condition. Engine damage may result.

Cancel actuator test mode. Check actual timing and compare with standard values. If timing is not within specifications, check Crankshaft Position (CKP) sensor, timing belt cover and CKP sensor installation conditions, and CKP sensing blade condition.

IGNITION TIMING SPECIFICATIONS (Degrees BTDC @ RPM)

Application

⁽¹⁾ Base

⁽²⁾⁽³⁾ Actual

1.5L

2-8 @ 600-800

10 @ 600-800

1.8L

2-8 @ 600-800

5 @ 600-800

2.0L

2-8 @ 600-800

8 @ 600-800

2.4L

2-8 @ 600-800

10 @ 600-800

3.0L

2-8 @ 600-800

15 @ 600-800

3.5L

2-8 @ 600-800

10 @ 600-800

⁽¹⁾	Ignition timing is not adjustable.

⁽²⁾	Timing will be advanced at higher altitudes, 5-15 degrees, depending on model and altitude.

⁽³⁾	Actual ignition timing is approximate and may fluctuate plus or minus 7 degrees.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Ignition Timing

Use the Manual With the Right Hardware

When to See a Mechanic

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