Diagnostic connector

When inspecting a secondhand MINI Cooper convertible, I was advised it was a Cat D write-off with a replacement engine and the ABS and TPS lights were illuminated on the dashboard. I plugged in my Autel scanner, but got nothing. So I got a torch and could see that on top of the diagnostic socket there was an extra wire scotch-locked into the wiring entering the socket. Otherwise, the engine runs well, the convertible hood has no issues, the leather is all good and it’s got eight months of MOT. Any advice? Stephen Haywood

The first check to make is that the diagnostic socket is wired correctly and ascertain why the extra wire has been jumped into the loom. It may simply be there to take a live feed off the circuit to power another component. The diagnostic socket should have seven wires connected to terminals 1, 4, 5, 7, 8, 9 and 16. With the wide section of the socket at the top and the terminals facing you, the connections are numbered from left to right starting on the top row. Terminal 1 is fed from the ignition, terminals 4 and 5 are a constant live feed, terminals 7, 8 and 9 are the data links and terminal 16 is a switched feed.

As a starting point, I would disconnect the joined wire, ensure that the live feeds are present and then re-attempt to code-read the vehicle. MINI wiring can suffer from problems and it may be the case that the fault is with the main loom running through the bulkhead on the nearside of the vehicle. Check this loom for any marks – particularly a brown rust-type stain – that could indicate a broken wire internally.

According to the gov.uk website, the MINI had a note on the MOT to ‘Repair as soon as possible (minor defects)’ the ‘Offside front inner driveshaft joint constant velocity boot severely deteriorated’. I would check this has been rectified before any water gets into the joint.