P0921

Gear Shift Forward Actuator Circuit Range/Performance

Q: Is it safe to drive with P0921?

Often not — the car may not engage a forward gear. Have it repaired before you rely on the vehicle.

Q: Can I just clear P0921?

It clears, but returns as soon as the actuator fault reappears. Fix the actuator or circuit first.

Transmission / shift actuator Generic OBD-II Medium

What it means

P0921 means the gear-shift forward actuator circuit is performing outside its expected range on an automated-manual transmission. This actuator moves the mechanism into a forward gear; when the controller detects a fault it may be unable to engage drive, leaving the transmission stuck in neutral or another gear.

Medium

Can I keep driving? Engine starts, but the transmission may fail to engage a forward gear and could be stuck in neutral — you may not be able to drive, so repair before relying on the car.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Difficulty engaging a forward gear
Delayed or no response when selecting drive
Transmission stuck in neutral or another gear
Check-engine or transmission warning light on

Common causes

Most likely first

Faulty or damaged gear-shift forward actuatorLikely
Wiring problems or loose connections in the actuator circuitCommon
Hydraulic problem in the transmissionCommon
Faulty transmission control module (TCM)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and inspect the actuator connector and wiring for faults.
Check power, ground, and control signals at the actuator.
Test the actuator and inspect related transmission hydraulics.
Replace the forward actuator if faulty; evaluate the TCM only after wiring and actuator test good. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0921?+

Often not — the car may not engage a forward gear. Have it repaired before you rely on the vehicle.

Can I just clear P0921?+

It clears, but returns as soon as the actuator fault reappears. Fix the actuator or circuit first.

Read & clear P0921 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX