OBD-II trouble code
P0928: Gear Shift Lock Solenoid Control Circuit/Open
An open circuit on the shift lock solenoid — the small device in the console that keeps the lever in Park until your foot is on the brake. It has nothing to do with how the transmission shifts, and every car has a hidden manual override for exactly this situation.
Quick facts
- System
- Powertrain
- Category
- Transmission / Shift Control
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $60 – $600
- DIY difficulty
- Intermediate DIY
What does P0928 mean?
P0928 is stored when the module driving the gear shift lock solenoid finds that circuit open — no current path to the solenoid when it is commanded to release. This code sits in the transmission block by number, but the component it describes is not inside the gearbox at all, and understanding that saves a great deal of unnecessary worry.
The shift lock solenoid lives in the centre console, in or beside the gear selector assembly. Its entire job is a safety interlock: it physically blocks the selector lever in Park and withdraws that block when the ignition is on and the brake pedal is pressed. That is the whole function. It does not choose gears, it does not influence shift quality, it has no relationship with the clutch, the valve body or anything hydraulic. A vehicle with this code has a fully healthy transmission and a lever that will not come out of Park — an inconvenience of the highest order and a mechanical problem of almost none.
Because the solenoid depends on a brake pedal input, the most useful test on this code costs nothing and requires no tools. Walk behind the car and have someone press the brake. If the brake lights do not come on, the brake light switch is the first suspect, not the solenoid: the same switch commonly feeds both, and a failed switch produces a lever that will not release along with a car whose brake lights have quietly stopped working. That is a cheap, common and frequently missed cause, and checking it before removing a console is simply good sequence.
Every vehicle fitted with this interlock is also required to have a manual override, and knowing where it is turns a recovery call into a two-minute job. It is normally a small slot or removable cap next to the selector, sometimes under a trim panel or a rubber plug, into which a key or screwdriver is pressed to release the lock mechanically while the lever is moved out of Park. The owner's handbook shows the location. Using it is not a repair and it does not clear the code, but it does let a car be moved off a driveway or onto a ramp without drama.
One genuine safety point belongs alongside the inconvenience. This interlock is what prevents a vehicle being taken out of Park without the brake applied. If the fault has left the lever moving freely without the pedal — rather than locked — the protection is gone, and that deserves more urgency than a car stuck in Park does.
Common causes
- Failed brake light switch no longer signalling that the pedal is pressed
- Open winding in the shift lock solenoid
- Connector unseated or damaged at the selector assembly
- Broken conductor in the solenoid control circuit under the console
- Blown fuse shared with the brake light or interlock circuit
- Corrosion in the connector following a spill into the centre console
- Wiring damaged during aftermarket console, audio or shifter trim work
- Misadjusted brake light switch that no longer closes on pedal travel
- Open ground for the selector assembly
- Failed driver output in the module controlling the interlock
Symptoms
- Gear selector locked in Park with the brake pedal pressed
- Brake lights not working when the pedal is pressed
- Lever releasing only after repeated attempts or not at all
- Warning lamp with a transmission or shift interlock message
- Key unable to be removed from the ignition on vehicles with key interlock
- Selector moving out of Park without the brake pedal pressed
- Fault appearing after a drink or liquid was spilled into the console
- Fault appearing after aftermarket work around the centre console
- No audible click from the console when the brake pedal is pressed
- Transmission shifting perfectly once the lever has been released manually
Diagnostic steps
- 1.Check the brake lights first with someone pressing the pedal — no brake lights points at the brake light switch rather than the solenoid.
- 2.Check the fuses covering the brake light and interlock circuits before removing any trim.
- 3.Listen at the console for a click as the brake pedal is pressed with the ignition on, which tells you whether the solenoid is being energised at all.
- 4.Locate the manual shift lock override in the owner's handbook and use it to move the vehicle without forcing the lever.
- 5.Confirm the brake light switch closes properly through its adjustment range rather than only at full pedal travel.
- 6.Measure the solenoid winding resistance at its connector with the harness disconnected to identify an open coil.
- 7.Check supply and ground at the selector assembly connector with the ignition on and the brake pressed.
- 8.Inspect the console area for evidence of liquid spills, corrosion or sticky residue around the connector.
- 9.Review any aftermarket work in the console, since interlock wiring is easy to disturb during audio or trim installation.
- 10.Back-probe the control output at the module only after the switch, fuse, wiring and solenoid have all been cleared.
Repair cost
$60 – $600
This is one of the cheaper codes in the P09xx block because the component is in the cabin rather than in the transmission. Diagnosis is $60 to $180, and a fair proportion of cases are resolved during it — a blown fuse or a brake light switch is often found in the first ten minutes. A brake light switch is $70 to $220 fitted. A shift lock solenoid is $110 to $400 fitted where it is supplied separately; where the manufacturer only sells it as part of the selector assembly, $250 to $600. Wiring repair under the console is $90 to $350. Nothing here involves removing a transmission, and a competent home mechanic can often handle the fuse and switch checks.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with shift interlock (shift lock) solenoid replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.