HELP

[Ak303]

OK. Newbie here.

Just purchased and 03 A4 1.8T. Its a project and Im learning so any helpful advice is appreciated!

- Heavy rain flooded the ECU. Car wouldnt start.

- I purchased knowing it would be a project, cleaned the relays and it fired right up. Hyped. Been driving back and forth to work for several weeks. Seems like it had full power and everything seemed to be in order.

- Last week the CEL came on. Speedometer and Odometer stopped working. Ran VAG and 1 code came up - "Speed Sensor"(crankshaft)......Been driving perfect the entire time.

- Last night I went out and it wouldnt start. Turns over and seems like it wants to but wont.

- Looked into the speed sensor(crankshaft) online and found a thread with a similar situation. Purchased a new one and installed which was a bitch to get to. Didnt do anything.

- Next day I got some new relays to replaced the ones I had previously cleaned. 219 and 395. Installed, still nothing.....

Whats the next step? Fuel pump?

 

[QuattroCalum]

OK. Newbie here.

Just purchased and 03 A4 1.8T. Its a project and Im learning so any helpful advice is appreciated!

- Heavy rain flooded the ECU. Car wouldnt start.

- I purchased knowing it would be a project, cleaned the relays and it fired right up. Hyped. Been driving back and forth to work for several weeks. Seems like it had full power and everything seemed to be in order.

- Last week the CEL came on. Speedometer and Odometer stopped working. Ran VAG and 1 code came up - "Speed Sensor"(crankshaft)......Been driving perfect the entire time.

- Last night I went out and it wouldnt start. Turns over and seems like it wants to but wont.

- Looked into the speed sensor(crankshaft) online and found a thread with a similar situation. Purchased a new one and installed which was a bitch to get to. Didnt do anything.

- Next day I got some new relays to replaced the ones I had previously cleaned. 219 and 395. Installed, still nothing.....

Whats the next step? Fuel pump?

It's hard to say but, you never know what damage the flood has done to the integrity of the wiring loom and it's connections, you might be lucky (as you already have been) are any of those two relays for the fuel pump? Any other codes been thrown up?

 

[MrBonez]

corrosion is a silent killer.
my guess is everything is now starting to corrode and kill everything within the ECU and anything else the water got into.
i sorry to say i think you will need a new ECU buddy.

 

[Ak303]

Totally understand. Appreciate the feedback.

No doubt you may be correct........however......

Took a break and let the car sit for a few days as its not my main means of transportation. Wiggled the sensor around and it started right up. Cruised it around for the day, got home and parked. Came out to check it after 20 min or so and it wouldnt fire up. Next morning it would. Randomly, tried it several times this week and its started, just havent driven it anywhere because I dont want to get stuck if it decides not to start when Im out.

Day off tomorrow and Im gonna pull the sensor, clean everything up and put it back in case theres a poor contact? We'll see what happens.

Ive found several ECUs locally I can grab for a reasonable price. No idea what I would need to do from there. Hopefully I can figure it out? If that is the case. As mentioned its somewhat of a project and Im here to learn so any help or ideas is appreciated.

 

[QuattroCalum]

Next time it doesn't start keep an eye on the rev counter, if the needle doesn't lift off the stop while you're turning it over points to the crank angle sensor. The crank angle sensor never just fails, it will give a lot of different type fault,ie hard to start, dropping out while driving, lurching when pulling away from a junction etc, hopefully that's all it is.
If the worst comes to the worst and it's the ECU at fault you'll need someone with full VCDS or similar to read ECU and IMMO pins to swap from existing to replacement ECU. A little info in the link below regarding ECU swap.

http://wiki.ross-tech.com/wiki/index.php/Immobilizer_III_ECU_Swapping

 

[Ak303]

Pulled the crank sensor out and cleaned around it. Put it back in and it fired back up. Going on 4 days and its fired up every time. Great news. I have been a little nervous to drive it anywhere besides work and back, fearing it may not start up again, but Im starting to be more confident that the sensor just wasnt making a clean connection.

However, the speedometer and odometer still arent working?

 

[QuattroCalum]

Pulled the crank sensor out and cleaned around it. Put it back in and it fired back up. Going on 4 days and its fired up every time. Great news. I have been a little nervous to drive it anywhere besides work and back, fearing it may not start up again, but Im starting to be more confident that the sensor just wasnt making a clean connection.

However, the speedometer and odometer still arent working?

That sounds encouraging, as regards the speedo, it runs from a sensor on the gearbox
https://www.google.com/search?site=...0i30j0i8i30.Mip5ORB_sWM#imgrc=wSLX3BD3XzFYOM:

This image is from a Passat but it's the same gearbox, the speed sensor is the one closest to the drive flange, might just need a clean but could you be that lucky twice?

 

[Ak303]

Sorry Im not sure what Im looking at? The link pulled up google images but none of them are consistent?

Anyways. Car has started everytime since last post