Step 1: Check The Speedometer
CAUTION:
To prevent damage to scan tool MB991502 or MB991958, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502 or MB991958.
- Connect scan tool MB991502 or MB991958 to the data link connector.
- Use scan tool MB991502 or MB991958 to enter a simulated vehicle speed.
Does the speedometer correspond with the simulated vehicle speed?