P3 d5 issues

Philia_Bear

This one has me scratching my head

P3 08 S80 d5 ~280k km

Drives perfectly, pulls hard as it was when new

Did the swirlflaps and cleaned EGR etc about 6 months ago and it was perfect until now

At idle only, it seams like one injector drops out for one pulse occasionally

When it happens the lights dip briefly which has made me think it's the alt causing issues

I did the alt test and it passed the test but only just (voltage wise) and during half of the load tests the lights inside were doing odd things

Also did a regen and that went fine and result went from 18 back to 0

Injectors are changing slightly except for #4 which sits at +1.4mg all the time

Only code are that it thinks the rear high mount light is broken when it working fine

Cem-b111513

And it's complaining about the brake pedal switch A

Bcm-c004064

But again odd as everything working fine

My next thoughts are

1 remove the trailer control module I added that never worked right

2 sacrifice 3 chickens and read the entrails

3 try a different alt (I have a spare)

Philia_Bear

I'll take any thoughts even bad ones

DCW242

It's very common for them to get corrosion in the negative battery cable, it's worth checking the condition of that. Also they are very sensitive to batteries, my parents XC70 D5s constantly go through a high quality battery every 4 years.

My parents 2008 XC70 D5 did something similar a while ago, it was a dodgy injector connector, we crimped a new terminal on and it was fine. I can't remember exactly what the codes were though.

Ex850R

The fuseable link on the battery clamp is a problem on higher mileage cars.

Berry's remove it completely, I was hatting with Dave as he was doing this on an XC70 , I didn't ascertain what the resulting symptoms were but he said the link always causes problems.

Worth doing at least....

As he said, the car has more than enough circuit breakers etc anyway.

timbo

Probably worth tightening up the pins on injector connectors and trying the spare alternator.

Trailer module is probs causing the brake switch and centre light code if brake signal is spliced in.