Question 1

What does fault code U0140 mean?

Accepted Answer

U0140 is a CAN bus network fault meaning the main vehicle computer has lost communication with the Body Control Module (BCM). The BCM controls central locking, exterior lighting, wipers and cabin electronics. When communication drops, those systems misbehave or stop working entirely.

Question 2

Can I drive my car with a U0140 code?

Accepted Answer

Short trips in daylight may be possible, but you risk losing indicators, brake lights or wipers without warning. We strongly advise getting it diagnosed promptly rather than risking a dangerous situation or an MOT failure on lighting circuits.

Question 3

How much does U0140 diagnosis cost in Barnet?

Accepted Answer

MnF Motors charges from £65 for a full electrical fault diagnosis session. That covers oscilloscope-level CAN bus testing, connector inspection and a written report. The repair quote is agreed with you before any parts are touched.

Question 4

Does a U0140 code always mean I need a new BCM?

Accepted Answer

No — in our experience the majority of U0140 faults trace back to a damaged earth strap, corroded connector or chafed CAN-Hi/CAN-Lo wire rather than a failed BCM. Replacing the module without diagnosing the root cause simply repeats the fault on an expensive new part.

Question 5

How far does MnF Motors travel to serve Barnet customers?

Accepted Answer

Our workshop is in Edmonton N18 — roughly 8 miles from central Barnet and easily reachable via the A406 or A110. We serve all of Barnet borough and every postcode within 20 miles of Edmonton. For complex engine or mechatronic work we can arrange nationwide service.