Engine Light & Fault Codes

Hi All

The engine management light has come up on my 2004 A4 1.9 TDI. I've scanned for codes and got the following:

1. P1256 - Engine coolant temp sensor (G62): Open or short to plus
2. P0571 - Brake switch (F): Implausible signal

Can anyone help me with the following:

1. I'm presuming that both of these components need replacement?
2. Where is the temp sensor located?
3. Where is the brake sensor located?
4. Brake lights and all other electrical features seem to function fine so why is it saying fault on brakes?

Thanks in advance

The break light switches on all VAG cars go wrong quite frequently. Sometimes it means the brake lights stop working ome times you get the MIL light up on the dash. The switch is located at the top of the brake pedal. It is small connector with a plunger, simply twists out. Check all the connections and wiring around the switch, also check the brake lights fuses and all the bulbs to make sure there are no problems there. If nothing found then change the switch. The brake light switch is really easy to replace and only costs about £7 from Euro Car parts.

With the coolant sensor again check the wiring cna connectors around it looking for breaks or loose connections.

What is your engine code?

Cheers for the advice, I'll check those things this weekend.

This morning I noticed that the engine ideled erratically and then settled. Only briefly and only once but it jumped from just under 1000RPM to just over 1000RPM and then wobbled before settling down. Engine runs at 90 degrees constant.

The engine code (if I've deciphered my chassis no right) is WAUZZ8E - please correct me. have I got this right?


Anyone tell me where the temp sensor would be located in this engine?

Cheers

The engine code is a three letter code, e.g. AML. It can be found on the white sticker in the spare wheel compartment.

get both parts from gsf euro or dealer they dont cost much
both are very easy to change and very common to fail
use the search theres a few how to's knockin around

If it's 130, it may be AWX, or AVF if quattro.

The coolant sensor is right at the back, underneath the EGR pipe - there it goes into the flat platic pipe. You'll need to remove it to get to it, it's in a really awkward place!

Just checked the spare wheel compartment...no sticker. My car is 6 speed TDI. Pretty sure its 130BHP. Not the FSI model. and an 04 plate not a 54 plate. Probably AWX. Is the engine code significant.

Ta for the tip I'll search about the forum for a how to guide and replace the parts and clear the fault codes. Sounds like a job I can tackle.

What's the EGR stand for and what does it do?

Cheers

EGR is ther exhaust gas recirculation valve. It does what it says, send the exhause gasses back into the engine for another burn to lower emmissions (or something like that. As you stand in fron of the car, it's the little mushroom-like shiny metal thing at the back left of the engine bay - under the engine cover.

Cheers for the excellent description. I'll tackle things tomorrow. Pain that it's in an awkward place.....always the way eh?!

I know, easy as pie on my MkIV Golf because the engine is mounted londitudionally! Expext several scratches on your wrist and to get poked by the little metal plunger thingy.. you'll see!