The warning light is coming on and flashing when I have been driving the car about 10 miles and the car then goes into limp mode. I had a diagnostic test done and it says there is a fault in cylinder 1 and 4 glow plug circuit. I have changed all the glow plugs but it is still doing the same. Please can anyone help ?

You might want to add what car and engine you have, how many miles it's done and if there are any other fault codes since changing the glow plugs

Sorry and thanks. Skoda Octavia 1.6 tdi, 2010. It's done 150,000 miles. It's still coming up with the same fault.

Did you check the old glow plugs had failed? Assuming you've checked the resistance of the new glow plugs too, next thing is to check the wiring harness for them.

 

It might be worth posting the exact error codes you have to give a better idea what the car is reporting.

Error codes are P067100, Cylinder 1 glow plug circuit

                            P067400, Cylinder 4 glow plug circuit

Yup, those tie in with what I've said so far:

- http://wiki.ross-tech.com/wiki/index.php/17055/P0671/001649

- http://wiki.ross-tech.com/wiki/index.php/17058/P0674/001652

 

Another engine but should give you an rough idea of how/what to check http://forums.tdiclub.com/showthread.php?t=79819

 

I wouldn't expect glow plug faults to cause a warning light or limp mode, at least it didn't on my '61 plate when a couple failed. I only found out during a routine scan.

Ok update on the skoda, it's an EGR fault P040100 and P040300 Is there a quick fix or do I need to replace it. I have not had the VW emissions upgrade done. 

I had this fault happen on my 09 vRS. I initially thought it was the EGR but It was the Turbo Actuator and thank god around £250 cheaper (and that was a at a VW specialist.)