VSA (Vehicle Stability Assist)

DTC 21: Difference in Wheel Speed

NOTE: A wheel bearing that is installed backwards can cause this DTC.

1. Check all four tires for size, inflation, and wear.

Are all four tires the correct size, properly inflated, and worn evenly?

YES-Go to step 2.

NO-Install the correct tires, a known-good set of tires, or set the tires to the correct pressure, and retest by test-driving.

2. Test-drive the vehicle.
3. Check the RF, LF, RR, LR WHEEL SPD in the VSA DATA LIST with the HDS.

Are all four the same indicated value?

YES-Go to step 4.

NO-Reinstall or replace the wheel sensor(s), and recheck by test-driving.

4. Check all magnetic encoders on the hub bearing units.
Are they installed correctly and in good condition?

YES-Check for loose terminals in the VSA modulator-control unit 46P connector. Check for a loose connection at G303. If necessary, substitute a known-good VSA modulator-control unit and retest.

NO-Replace the hub bearing unit(s), and recheck by test-driving:
^ Front: Replace the front hub bearing unit.
^ Rear: Replace the rear hub bearing unit.