1,9 tdi caddy cutting out 2009

[cbxman]

Hi everybody. just new on here but hoping someone has a cure for this problem. 2009 1,9 tdi caddy cutting out ,switch off. restarts immediately. codes on scanner are P1601 Voltage Supply Relay -terminal 30 implausible Signal.
01314 ECM No signal/ Communication 03 Brakes
09 Central Electrics
17 Dashboard
19 Gateway
I have changed the relay in the fusebox .checked power to the relay all ok. cleaned all earth points . but still cutting out .
Any info for a cure would be most helpful , thankyou

Hugh

[STP]

Sounds like a corrosion or water ingress issue. Weird unconnected fault codes. Check the BCM. It's under the steering column dash area, upper module from memory, above the cabin RHS fusebox.

If the canbus signal is interrupted between the internal BCM and the external engine ECU, can cause weird behaviour.

[cbxman]

Thank you for replying, I'll check that , another update , engine will run perfectly when stationery but once on the move stutters and cuts out, again moving wires and cables about when stationery engine runs perfectly no hesitation at all, could the ECU be on it's way out or faulty ABS module as this is only happening when on the move,

[STP]

Canbus comms wiring between modules is always a twisted pair, one a plain colour and one has a stripe. Look for those and check for damage or corrosion. Coiled together like an old school phone cable.

Also check your engine bay fuse box for water and corrosion on the relay terminals.

While in there, check the ECU plugs, under the wiper scuttle panel.

[cbxman]

Again , thankyou for replying , got ecu checked and reflashed all ok, refitted it , doing exactly the same thing again same dtc's . All connections in the fusebox and ecu are spotless and corrosion free, I'll look for the canbus wiring and check it , hopefully find something .