Gearbox Control Unit (TCM) Repair
Assessment fee deducted from an approved repair. Repair is not included in the assessment price.
Feedback from garages and vehicle owners
Professional repair, testing and return.
Price and payment
Every unit is different, so the final price depends on what we find on the bench. Not sure what is wrong? Choose the bench test (£45, deducted from the repair if you go ahead). Already know the fault? Order the repair at the standard price. If the fault needs more work, we send you a written quote for the difference and wait for your approval before doing it.
| Level 1 – Standard repair | £350 | The most common fault for this module, confirmed on the bench. |
|---|---|---|
| Level 2 – Extended repair | £550 | More extensive damage or several failed circuits. |
| Level 3 – Advanced repair | Quoted | Severe damage, previous repair attempts or data recovery. |
Every level includes diagnosis, final test, report and tracked UK return. If the unit cannot be repaired, you are refunded the price less the £45 diagnostic assessment and the unit comes back with the report. No VAT added – we are not VAT registered. Prices and terms · 12-month warranty.
UK postal repair for electronic transmission control units (TCM / TCU), including external units and, depending on design, units integrated with the gearbox. Faults show as limp mode, harsh or missing gear changes and communication errors.
Common symptoms
- Gearbox in limp mode or stuck in one gear
- Gearbox warning on the cluster
- Harsh, delayed or no gear changes
- No communication with the TCM
- Faults after water or oil reaching the unit
Not every gearbox fault is electronic
Fluid level and condition, wiring, sensors and mechanical wear cause similar symptoms. A bench test shows whether the control unit is at fault.
Common fault codes
| Code | Meaning (generic) |
|---|---|
U0101 |
Lost communication with TCM |
P0700 |
Transmission control system – TCM requested MIL |
What happens on the bench
- Intake – photos, job number, condition, signs of water or previous repair.
- Identification – part number, hardware and software versions.
- Data backup – memory read and saved before work where the unit allows it.
- Fault confirmation – supply, solenoid driver outputs, sensor inputs and communication are tested.
- Repair – the confirmed fault is repaired and checked.
- Final test and report – pass, partial or fail, with test limits stated.
How to send your unit
- Order the repair and enter the unit details – part number, registration and fault codes.
- Remove the module with the battery disconnected and note the part number from the label.
- Pack it in an anti-static bag with padding (packing instructions) and write the order number on the box.
- Post it with tracking or book a collection quotation.
- Request a progress update using your order or TTR reference by email or WhatsApp. Return transport arrangements are confirmed in your quotation.
FAQ
Will the module need coding after refitting?
Your original unit is returned, so in most cases its coding stays in place. Any in-vehicle steps needed (for example a basic setting or calibration) are stated in the report.
Does the gearbox need adaptation after refitting?
Some gearboxes need an adaptation or learning procedure after work. Where this applies, it is stated in the report.
Compatibility is confirmed by complete part number and hardware revision. A vehicle make or model alone does not confirm that a unit is supported. Send a label photo before ordering.
VEHICLE FITMENT
Compatibility guideVehicle lists are identification guidance, not a fitment guarantee. Send the complete part number and hardware revision for confirmation before ordering. A similar-looking unit is not proof of compatibility.
