Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC 28-120
DTC 28-120 : Longitudinal Acceleration Sensor (Inside of Modulator-Control Unit) Stuck
NOTE:
- Before you troubleshoot, review the general troubleshooting information .
- The yaw rate-acceleration sensor is built into the VSA modulator-control unit.
- Before troubleshooting, check the VSA modulator-control unit for proper mounting. Improper mounting of the VSA modulator-control unit may set this code.
| DTC Description | DTC | Freeze Frame |
|---|---|---|
| 28-120 Longitudinal Acceleration Sensor (Inside of Modulator-Control Unit) Stuck |
DTCs (VSA)
- Problem verification
-1. Turn the vehicle to the ON mode.
-2. Clear the DTC with the HDS.
-3. Turn the vehicle to the OFF (LOCK) mode.
-4. Test-drive the vehicle at 6 mph (10 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.
-5. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame 28-120 Longitudinal Acceleration Sensor (Inside of Modulator-Control Unit) Stuck Is DTC 28-120 indicated?
YES
The failure is duplicated. Go to step 2.
NO
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting .
- Longitudinal acceleration sensor performance check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Test-drive the vehicle.
NOTE: Drive the vehicle on the road, not on a lift.
-3. Check the parameter(s) below with the HDS.
Signal Current conditions Values Unit LONGITUDINAL ACCELERATION SENSOR Does the indicated value change while accelerating or braking?
YES
The system is OK at this time.
NO
Go to step 3.
- VSA modulator-control unit check (update)
-1. Update the VSA modulator-control unit if it does not have the latest software .
-2. Turn the vehicle to the OFF (LOCK) mode.
-3. Test-drive the vehicle at 6 mph (10 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.
-4. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame Is DTC 28-120 indicated?
YES
Check for loose terminals in the VSA modulator-control unit 21P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit .
NO
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.
NO RELATED
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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.