P0700 means a fault has been detected in the transmission control system. UK repair costs and fixes for OBD2 fault code P0700.
This page explains the code in plain English and gives indicative UK repair and MOT context. It does not confirm the exact failed part. Vehicle age, engine, related codes, live data, and workshop inspection can all change the final diagnosis and quote.
P0700 means a fault has been detected in the transmission control system. UK repair costs and fixes for OBD2 fault code P0700. When this fault is detected, the ECU (Engine Control Unit) stores the code and usually illuminates the check engine light on the dashboard.
In practice, P0700 should be treated as a automatic transmission control problem first, not as proof that one named part has failed. The value of the code is in narrowing the system, checking related data, and avoiding the usual misdiagnosis before parts are ordered.
These are the most common symptoms UK drivers report when this code is active:
Note that some vehicles show no drivability symptoms at all — the check engine light may be the only sign. This is why scanning the fault code is essential rather than guessing at the cause.
These are typical causes to check first:
It is important to diagnose the root cause before replacing parts. Many unnecessary and expensive repairs happen because the most expensive component is replaced first without proper testing. Always work through the diagnostic steps systematically.
Work through these steps in order to avoid unnecessary parts replacement:
After any repair, clear the fault code with an OBD-II scanner and carry out a test drive. If the code returns, continue to the next diagnostic step. For a personalised repair guide specific to your vehicle's make, model, year and engine, use our AI Diagnostic Report below.
These models are frequently seen with this fault code in UK garages:
This code can appear on any OBD-II vehicle (all UK cars since 1996). The models listed above are examples where owners and garages often encounter this fault, but they are not an exhaustive or ranked list.
Difficulty: Hard — transmission diagnosis and repair requires specialist equipment. Not a DIY job.
UK repair cost estimate: £80–£600 including parts and labour at average UK workshop rates (inc. VAT). Independent garages are typically 30–50% cheaper than main dealers. Always get at least two quotes.
Prevention: Change transmission fluid every 40,000–60,000 miles, avoid aggressive driving habits.
P0700 is a gateway transmission code rather than a full diagnosis on its own. It usually means the gearbox control module has set one or more deeper faults that need a transmission-capable scan tool.
Treating P0700 as a standalone gearbox failure is the classic error. It is usually only a flag telling you to read the transmission module properly.
Fault code P0700 does not directly cause an automatic MOT failure, but an illuminated check engine light (MIL) is an automatic MOT failure under DVSA rules. If the warning light is on when you arrive for your test, the vehicle will fail. Get this fault diagnosed and the light cleared before your MOT appointment.
Even if the light is not currently on, if the fault is intermittent it could reappear during the test. Use our AI Diagnostic Report to understand the MOT risk specific to your vehicle and get advice on whether it is safe to proceed to your test.
Specific to your vehicle — year, make, model and engine.
Includes step-by-step repair guide, exact UK labour costs and MOT impact.
Can I drive with fault code P0700?
Drive with caution — transmission faults can cause unexpected gear changes. Get it diagnosed promptly.
Will P0700 clear itself?
Some fault codes will clear automatically after the underlying issue resolves itself, but P0700 typically stays stored until the fault is fixed and the code is manually cleared with an OBD-II scanner. Do not assume the problem has gone away if the light turns off temporarily.
Do I need a garage or can I fix P0700 myself?
Hard — transmission diagnosis and repair requires specialist equipment. Not a DIY job.
How much does it cost to fix P0700 in the UK?
UK repair costs for P0700 typically range from £80 to £600 depending on your vehicle, the root cause, and your local garage rates. Use our AI Diagnostic Report for a cost estimate specific to your car.
These fault codes are commonly found alongside P0700 or share similar causes:
Last updated: June 2026. AI-Diagnostics-Pro provides AI-generated information for educational purposes only. It is not a substitute for professional automotive advice. Always consult a qualified mechanic before carrying out vehicle repairs. Repair cost estimates are approximate and may vary by region and vehicle.
