Intermittent Check engine light

[Rapidrob]

'96 Passat TDI wagon.
For the last month or so I've been getting an intermittent Check Engine light when the engine is cold and the engine is at a lower than highway speed.

After ten minutes or so, the light gets very dim,flickers and then goes out and stays out.
I do not own a VAGCOM.
All of the vacuum lines are new. The engine NEVER goes into limp mode.
The vacuum pump is new.
I am not sure what all will turn on the CEL?
240,000 miles on wagon.

 

[Mozambiquer]

Well, you need to either get vag-com or take it to someone who does, since there are a gazillion things that could turn the check engine light on. Any error code in the computer could turn it on.

Sent from my S60 using Tapatalk

 

[Rapidrob]

I borrowed a VAG COM from a friend who owns an Audi. The error code said EGR valve, The sensor for the EGR valve is remote.
I removed the air box for the filter and the two air plenums and I found two "mouse chewed" wires in the bundle at the lower rear of the air box. A Yellow and Black wire and a White wire going to the quick disconnect plug to the remote EGR valve sensor.
I was able to solder the wires back together. I will do a test run later as I ordered a new air filter while doing the repair.

 

[Mozambiquer]

I borrowed a VAG COM from a friend who owns an Audi. The error code said EGR valve, The sensor for the EGR valve is remote.
I removed the air box for the filter and the two air plenums and I found two "mouse chewed" wires in the bundle at the lower rear of the air box. A Yellow and Black wire and a White wire going to the quick disconnect plug to the remote EGR valve sensor.
I was able to solder the wires back together. I will do a test run later as I ordered a new air filter while doing the repair.

There you go! Good job, welcome to the world of diagnostics!

Sent from my S60 using Tapatalk

 

[Steve Addy]

Awesome job, nothing better than finding the problem and doing it quickly!

Steve