Mercedes-Benz 9G-Tronic TCU Repair

SKU TRA2018

P073E00 – Reverse gear does not engage.
P07B700 – The pressure sensor signal is invalid.
Transmission will jerk once temperature is reached.
The selector position automatically shifts from D to N.
Other faults on request.

From £349.00

Fast Turnaround 2-5 working days

Warranty Protection Covering all our repairs

Choose your service

Repair Service (by post) Send us your unit — we repair and return it. Add to order and complete the quick vehicle form; free UK shipping label included. Send us your unit. We repair & return it. Free UK shipping label. £349.00 (Excl. 20% VAT)

Repair & Fitting (on-site) On-site removal & refit by our technician. Booked by phone only — call 01884 798090. Not available to order online. We remove, repair & refit the unit while you wait. Call 01884 798090 £899.00 (Excl. 20% VAT)

Replacement Units All replacements are sold on an exchange basis. If you need the unit shipped first, please contact our customer service. Brand-new replacement unit. £649.00 (Excl. 20% VAT)

Repl. & Fitting (on-site) Please call our customer service on 01884 798090 to schedule your appointment. No need to proceed to checkout. We remove, repair & refit the unit while you wait. Call 01884 798090 £1,199.00 (Excl. 20% VAT)

Service

Clear

★★★★★ “It’s good to have this gang on hand when it comes to gearbox electronics.” — Pawel P.

★★★★★ “Very professional , very prompt, well organised, thank you.” — Peter B.

★★★★★ “Good service on phone when ordering. Not able to say any more until part is fitted and see how it works!” — Eddie M.

★★★★★ “Had a part that was difficult to get hold of but they went the extra mile for a solution” — Johnathan M.

★★★★★ “Whole process of repairing my ABS module went smoothly without any issues. Staffs were friendly and professional. Will definitely use them again.” — zarif S.

★★★★★ “CU had great customer service and are very knowledgeable in what they do. Had a troublesome gear box mech which they sorted. Couldn't have been better to deal with. Highly recommend.” — Andy B.

Mercedes-Benz 9G-Tronic TCU repair

24-month warranty2–5 day turnaroundTracked return deliveryRepair or replacement

Two ways to fix the Mercedes-Benz 9G-Tronic TCU. Repair — send us your original unit, we replace the failed components on the board and return the same unit, so it keeps the coding and security data already matched to your car and needs no programming (24-month warranty). Replacement — a brand-new unit with data transfer included; your original still has to be sent in so we can copy its coding and adaptation data across (12-month warranty). Both usually turn round in 2–5 working days.

Not sure the TCU is the cause? The symptoms and the fault codes we see on this unit are listed under Common Faults. If your codes differ, send them over before ordering — if the unit turns out not to be faulty you only pay the test fee and return postage.

Which vehicles does this TCU fit?

This unit is used across Mercedes. Check your exact model and year under Matching Vehicles, or compare the number printed on your own unit with the part numbers listed on this page. The same hardware often appears under several part numbers — call 01884 798090 if yours is not shown.

Prefer not to remove the unit yourself?

Choose the on-site option and bring the vehicle to our workshop in Uffculme, Devon. We remove, refit and road-test it before you drive away, usually the same day.

Frequently asked questions

Should I choose repair or replacement?

Repair is the usual choice: you get your own unit back with its coding intact and a longer warranty. A replacement makes sense when the unit is beyond economical repair — it is brand new, and your original still has to be sent in so we can transfer the data across.

How long will I be without the unit?

We aim to complete all repairs within 2–5 working days. Should a repair take longer, we will contact you with an update. It goes back to you on a tracked service. Ask about on-site fitting if you need the car back the same day.

My part number isn’t in the list — can you still help?

Usually yes. The same hardware appears under many part numbers. Send us a photo of the label or call 01884 798090 and we’ll confirm before you send anything.

What warranty do I get?

Repairs carry a 24-month warranty and replacement units 12 months. See Returns & Warranty for the full terms.

Will the warning light go out after the work?

Yes, once the unit is refitted and the stored codes are cleared, provided the fault was in this unit. If a related wiring or sensor fault is also present it has to be fixed separately — we tell you what we found.

Common Faults

What are the symptoms of a failing Mercedes-Benz 9G-Tronic TCU TCU?

Harsh, jerky or delayed gear changes
Gearbox dropping into limp mode, or a complete loss of drive
Flashing gear indicator on the instrument cluster
A “gearbox malfunction” warning on the dash
No response when selecting D or R
The selector position automatically shifts from D to N.
There is a failure to select D.

Common fault codes

Fault code	Meaning
P073E00	Reverse gear does not engage
P07B700	The pressure sensor signal is invalid

Seeing different codes, or not sure the TCU is the cause? Call 01884 798090 — we’ll check your codes and symptoms before you send anything.

Matching Vehicles

Make	Model	Years
Mercedes	C-Class	W205 (2014-2021), W206 (2021-present)
Mercedes	CLS-Class	C257 (2018-present)
Mercedes	E-Class	W213 (2016-present), W214 (2023-present)
Mercedes	GLC-Class	X253 (2015-2022), X254 (2022-present)
Mercedes	GLE-Class	W166 (2015-2019), W167 (2019-present)
Mercedes	GLS-Class	X166 (2015-present), X167 (2019-present)
Mercedes	S-Class	W222 (2013-2020), W223 (2020-present)
Mercedes	SL-Class	R232 (2022-present)
Mercedes	SLC	R173 (2016-present)

How It Works

Place your order online — add the service you need to your basket. Before the item is added we ask for your vehicle details and fault codes, so we know exactly what we are working on.
Send us your unit — replacements are supplied on an exchange basis, so we need your original unit to transfer its coding data. Prefer to program the new unit yourself? Order first and send your original afterwards.
We do our part — we transfer your data to the new unit and test it, usually within 2–5 working days.
Tracked return delivery — by DHL Express or DPD, ready for installation.

On-site fitting — choose the on-site option and call us to book a slot. We remove, repair and refit the unit while you wait (usually 2–3 hours) and road-test the car before you drive away.

Need to know more? Call 01884 798090 or see How to order · Delivery pricing · Returns & warranty.

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Mercedes-Benz 9G-Tronic TCU Repair