2014 Transit 350 AWD terrain warning light - P2138 and U0401

[sythna]

You’re right, Mark. I did start going down that route and unplugged the MAF and accelerator pedal, but I gave up when I couldn’t confidently locate the throttle/air-doser sensor and didn’t want to start disconnecting random plugs.

The garage has now spent around 2–2.5 hours checking the loom and probing the sensor circuits, and they say everything they’ve tested is reading around 5V with no obvious wiring fault found.

They’re now pointing towards the injectors because it is smoking heavily and smells strongly of diesel. I’m still sceptical, though, because the self-revving started immediately after the accelerator pedal was unplugged and reconnected. I don’t want to start firing the parts cannon and spend hundreds testing injectors without properly explaining the P0653 or the timing of how the fault started.

[sythna]

A bit lost now. If I do go towards injector testing total with diagonistic, injector labour and testing is around £480.

[metalworker0]

How garages work ..well some of them .. cant find the fault .. clueless about it , find another fault, or create another fault from nowhere and get some money out of you!

You want a proper diagnostic tech , other than that, it's learn as you go! and experience the great sense of fulfillment when you alone, find out what it is and fix it yourself.

all the best......mark

[sythna]

Update on the Transit issue

Garage has now removed all 4 injectors and sent them for testing. The result has come back that all 4 injectors have failed. From what I’ve been told, 3 have failed both mechanically and electrically, and the 4th has also failed one of the tests.

The van was smoking heavily and smelling strongly of diesel, so this now makes more sense, but I’m still surprised that all 4 injectors have failed at the same time.

Before fitting replacements, I am asking the garage for:

- injector test report;
- checked for contamination, water or metal swarf

They’re quoting around £250 per injector, which feels a bit steep unless they’re quality recon/new units with warranty and coding included.

Question for anyone who knows these 2.2 Transits: if all 4 injectors fail, would you be checking the high-pressure pump/fuel system for contamination before fitting new ones? Also, does AWD make any difference to injector part numbers, or is it purely engine code/injector number based?