probably a daft ecu question !!!

[ericd]

I've been chasing a overboost problem for the last couple of weeks, eventually found a slit in the accordion hose at the turbo connection, changed this before I went to Audi Driver Int'l and everything seemed fine, recently though same old familar symptoms in 4th & 5th at around 3.5-4k revs; I decided to use the vag.com at the garage to look at the faults; any way to cut a long story short..., I cleared all the errors , gave it a good run and now seems back to full performance.

My question is , would errors logged in the ecu from a previous boost problem
cause it to "remember" the problem until the faults are cleared (is it that clever ??), or am I bluffing myself into thinking this is fixed when in reality it'll come back anytime

[S2central.net]

I've been chasing a overboost problem for the last couple of weeks, eventually found a slit in the accordion hose at the turbo connection, changed this before I went to Audi Driver Int'l and everything seemed fine, recently though same old familar symptoms in 4th & 5th at around 3.5-4k revs; I decided to use the vag.com at the garage to look at the faults; any way to cut a long story short..., I cleared all the errors , gave it a good run and now seems back to full performance.

My question is , would errors logged in the ecu from a previous boost problem
cause it to "remember" the problem until the faults are cleared (is it that clever ??), or am I bluffing myself into thinking this is fixed when in reality it'll come back anytime

You are right Eric - the ECU remembers faults until they are cleared by VAG-COM or you pull the fuses/battery for a minute or more. The stored fault codes would not miraculously go away just cos you cured a leak.

[Mihnea]

You are right Eric - the ECU remembers faults until they are cleared by VAG-COM or you pull the fuses/battery for a minute or more. The stored fault codes would not miraculously go away just cos you cured a leak.

ok for the fault codes, however engine behavior will be ok after restarting the engine, at least until the next hose pops. the ECU automatically resets itself on every startup and doesn't go into limp mode before the problem actually occurs again, even though there's a fault code stored. the fault code will be stored as "sporadic" or "intermittent" until the error occurs again.

HTH,

Mihnea

[Jay]

ok for the fault codes, however engine behavior will be ok after restarting the engine, at least until the next hose pops. the ECU automatically resets itself on every startup and doesn't go into limp mode before the problem actually occurs again, even though there's a fault code stored. the fault code will be stored as "sporadic" or "intermittent" until the error occurs again.

HTH,

Mihnea

disconnecting battery/pulling fuses will only clear some codes e.g intermitant non-important faults, persistant important faults ahave to be erraised by a fault reader/ diagnostic scanner, I can't remmember if the motronic system is advanced enough to store perminant codes.

[Mihnea]

disconnecting battery/pulling fuses will only clear some codes e.g intermitant non-important faults, persistant important faults ahave to be erraised by a fault reader/ diagnostic scanner, I can't remmember if the motronic system is advanced enough to store perminant codes.

ALL fault codes are erased by disconnecting fuses/ECU/battery, the ECU's fault code memory is RAM, so it's not permanent. 1.8Ts and newer TDIs have EEPROMS to store fault codes, and you can disconnect the battery for years if you want to erase them, without a scan tool you won't be able to.

HTH,

Mihnea