Hello everyone.

This problem relates to a Fabia 1.4 16V - the BBZ engine.

I've had an EGR fault code almost since we brought the car but it's never stopped the car

17848 - EGR Valve (N18) 
            P1440 - 35-10 - Open Circuit - Intermittent

But now I'm getting

1 Fault Found:
17848 - EGR Valve (N18) 
            P1440 - 35-00 - Open Circuit
Readiness: 1010 0101

 

The car now turns over but will not start. I've been trying to find some wiring diagrams online so I could test the wiring harness and/or EGR valve but to no avail. Could this change in error code be the unit rather than the wires? Any other suggestions? I realise that EGR valves seem to be quite cheap and easy to fix but I don't want to replace the valve if that isn't the issue.

Pin 1 black/red wire at EGR, +12V to solenoid from fuse 7

Pin 2 red/green wire, +5V from engine ECU pin 98 (Goes to 'top' of position sensing potentiometer)

Pin 3 Not connected

Pin 4 brown/blue wire 'sender earth connection' from/to ECU pin 108 ('bottom' of position sensing pot)

Pin 5 purple/white wire, modulated solenoid ground from ECU pin 114

Pin 6 green/white wire, wiper of position pot to ECU pin 100.

 

I'm surprised this fault is causing the car not to start. Check especially the pin 1 and pin 4 connections, as those also go to other sensors, which may be the real problem with the starting.

 

Don't buy the cheapest replacement EGR if all the wiring seems OK, you may have to buy twice if you do. Pierburg branded replacement advised, I suggest.  Should have an adaptation done using VCDS after installation, to educate the ECU about the potentiometer resistances at each movement limit.

Just unplug the EGR valve to start it.

Wino

If you are sure about pin 6 goes to pin 100 on the ECU , then I've found my problem . I have a break somewhere along that wire. My multi-meter's probes are too big to fit in the ECU pin-block connector, but a sewing needle fits and I can measure from the needle to Pin 6 of the EGR connector - open circuit.

 

I'm thinking, put in a replacement wire between the EGR connector and the ECU connector,  not following the existing wiring harness but a short-cut across the engine. However, any other ideas gratefully received.

In the mean time, can I damage the car driving it with the EGR valve not functioning correctly?

In the mean time, can I damage the car driving it with the EGR valve not functioning correctly?

 

No.

 

 

16 minutes ago, jverdicchio said:

Wino

If you are sure about pin 6 goes to pin 100 on the ECU , then I've found my problem . I have a break somewhere along that wire. My multi-meter's probes are too big to fit in the ECU pin-block connector, but a sewing needle fits and I can measure from the needle to Pin 6 of the EGR connector - open circuit.

 

I'm thinking, put in a replacement wire between the EGR connector and the ECU connector,  not following the existing wiring harness but a short-cut across the engine. However, any other ideas gratefully received.

 

Will double check right now. Short-cut wire will be fine.

 

Edited 30 November, 20205 yr by Wino

Yep, green/white from pin 6 of EGR to engine ECU pin 100.

 

 

Wino, you're a star! Thank you very much.