P0400 Fault code help needed PLease.

[Nick1]

Hi to all, nice forum you have here.

I have a fault light on my 05 vectra 1.9 CDTI 120 bhp.

Code P0400, I cleaned my EGR valve and cleared the codes but within 5 Min's the fault comes back.

Replaced EGR with brand new 1, but still getting the code returning after 5 min's.

Checked old EGR by just plugging in and when reeving the engine its opening and closing ok so I assume that is not the fault.

DPF Regen's now and again when needed.

Just don't know where to go from here any suggestions would be much appreciated

Thanks in advance.

[Damo77]

I am in the same boat as you Nick

I too had the same fault code P0400 (on my CDTI 120), so I went and replaced the EGR with a new one but still have the Spanner light on the dash lit up.

I cleared the code with my scanner "U-480" but the spanner light just comes back on but now not showing any fault code at all

I will be watching this thread with interest, hopefully some of these kind folk will be able to offer any suggestions as to what is at fault.

The next thing I am going to try is clean the boost sensor and have a good look around for any cracked/leaking hoses.

Best of luck getting yours sorted, oh and welcome to Vectra-C
Damo

[dh.dti]

check the vac system for leaks

[danman487]

I think (and i may be wrong) but only tech 2 and op com will read the car and spanner codes. My u480 wont read car n spanner light codes.

Again, may be wrong but i think p0400 will bring up the engine management light n not the car n spanner light. As far as i understand the car n spanner light is the electronics, so may be the boost sensor or something like that.

Hopefully someone will be along to correct me if im talkin rubbish

[Nick1]

Sorry forgot to mention the engine management light is on and staying on.

The car and spanner is only coming on for a short time when starting the car up.

The car passed the MOT last week with flying colours.

Just been out and checked as many hoses as i can find and cant find anything leaking.


Thanks for the replies

[danman487]

In that case i reckon glow plugs causing car n spanner light

[Ste]

Firstly, lets not get carried away with ourselves. I cannot see how glow plugs would trigger P0400, which is Exhaust Gas Recirculation Flow Malfunction.

The car and spanner light means there is a fault. If the MIL comes on, then the car and spanner light will usually go out. Not all car and spanner will put the MIL on, only certain ones that affect emissions.

Right, so you have changed the EGR valve and the same thing happens.
You have checked the vac tubes etc, and they are ALL OK?

Remind me, is the 8V 1.9 EGR electric or vacuum operated?

Are all the wires in good condition, and the multiplug clean and dry?

The next thing I would do is to disconnect the MAF, clear any codes and then start the engine and see what happens. What codes come up now?

[the-wizard]

Nick, have you cleaned the boost sensor ?, this code refers to insufficient egr flow, ie 2 sensors are not getting the same readings between them.

[Nick1]

Hi.

Not cleaned any sensors, where abouts is this situated.

Thx.

[danman487]

Sorry, wasnt getting carried away, just goin by my own experience with my vectra, it had egr issues and once that was semi sorted the car n spanner light kept coming on for the first few mins of driving. Wen i changed the glowplugs the car n spanner light disappeared and hasnt been seen since