Hi all, going to attempt to give as much context as possible because this feels like a weird electrics problem and also we are not mechanics.. he has some car experience and I am electronics and computer related so between us we can probably follow instructions..

My partner’s estate had a strange problem where it would refuse to start after being run for a while, but did start again after being left. It recently had the same problem but had to be recovered, and hasn’t started since. It cranks but doesn’t turn over at all.

We’ve had trouble finding mechanics to look at the problem (we are Luton way) but one guy did come by and say it was a dodgy fuel pump. Hard to get hold of these but he (partner not mechanic who is on holiday or summat) swapped it out for a second hand part and it is making the same noise apparently - which to me sounds almost bubbly, like a blockage, air leak or just weird pwm action?

After poking around in the forums I’ve noticed quite a few problems turning out to be dodgy relays - and the odbc errors are below:

P0230 [0x0230]

Fuel pump relay - circuit malfunction

Fuel Pump Primary Circuit Malfunction

Status: Pending

----------------------------

P0030 [0x0030]

Heated oxygen sensor (HO2S) 1, bank 1, heater control - circuit malfunction

Status: Pending

----------------------------

P0036 [0x0036]

Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit malfunction

Status: Pending

----------------------------

P0104 [0x0104]

Mass air flow (MAF) sensor/volume air flow (VAF) sensor - circuit intermittent

MAF Circuit Intermittent

Status: Pending

I can’t seem to find docs showing what relay is definitively related to the fuel pump but I did take the attached pic with the ignition on.. tested swapping the 645 that isn’t hot and it also started heating, so the problem seems downstream?

Hoping something of this makes sense to someone because I am still traumatised from dealing with the glowplugs on my van and am developing an abiding hatred of nassty stinky dieselses, precious…

Further investigations:

I believe the battery was disconnected for c.30secs last night, and it’s now getting angry about everything - but nothing showing up after a dtc clear (except open circuit on the pump control module when I took it off to check voltages etc)

The module seems to get power ok, the wires are good to the pump - the pump doesn’t seem to get power all the time, and when I tried to do a live read of the power output the battery had had enough so is being recharged.. it seemed to spike to a c4v in the brief moment it turned over.

No idea what I’m look for or at but I feel like there should be some sensor combo that should be able to tell me where in the system the actual problem is?? The 170 and 1700 seemed to flip between that and 450/4500 which seemed weird and borked sensor-ish but maybe that is normal in car land. Car electronics are absolute chaos and I have enough unruly computers in my day job! Aaaa