CSW_Scoobie

This is strange, but maybe someone might have heard of this problem before. I have a facelift classic MY99 wagon, basically towing the tin tent @60mph in fifth gear after a few miles the Check engine light comes on. Tow in fourth and it stays off, however this can get a little noisey after a while.

Any ideas why it may do this?
I will connect the green plugs next week when the tin tent comes out again.

Thanks in advance.

Splitpin

Green plugs are the wrong ones, they put the ECU into test mode. If you want to read its memory, you need to connect the black plugs.

And, don't wait til next week, do it now, as it'll have a record of any historic error codes.

And no, off top of head no immediate explanations, but if you can throw the trouble code(s) at us, it should get easier.

CSW_Scoobie

Thanks Splitpin, will get the codes posted tomorrow.

Scooby715

My money is on the simple and obvious choice... MAF.

My 00 Turbo used to do it whenever i put my foot down going up the slip road on to the m/way going from fourth to fifth, and it was throwing up code 23 (MAF sensor).

So i did the obvious thing and went a different way home from work!!!

...Only joking, i changed the sensor and the problem buggered off

CSW_Scoobie

Codes from the car are as follows, one of which I am sure has nothing at all to do with it(53);

41 - Air/Fuel adaptive control
62 - Exhaust Manifold valve negative pressure control solenoid
53 - Antenna
53 - Anti-Quick Operation Mode
53 - Communication Error (Time Over)
53 - EGI Control Module EEPROM
53 - IMM Circuit Failure (Except Antenna Circuit)
53 - IMM Control Module EEPROM
53 - Key Communication Failure
53 - Reference Code Incompatibility
53 - Use of Unregistered Key

Any more clues from that?

Scooby715

WTF???? Don't get that mate there's loads of codes there, how did you read them from the ecu? Did you use the method described on scoobypedia where you plug the black 'read' plugs in and convert the CEL flashes to numbers to get the codes, or have you used some sort of code reader??

I'm suspecting the latter which would explain the strange comms error codes etc??

Splitpin

Hmmmm, something strange is going on here. CSW - something I probably should have ascertained previously. You do have a turbocharged car don't you?

The reason I ask is that it's simply impossible to get errors 41 or 62 on a 99-00MY turbocharged Impreza, the ECU doesn't have the code to generate those errors in its firmware. You certainly can get error 53 on a UK/Europe market car, but as you say that should have nothing to do with an intermittent fault when the car's being driven.

So, are you reading those codes as the light flash sequence off the check engine light, or with some sort of plug-in reader? If the latter it's clearly not working right. If the former, are you sure you're interpreting the flashes correctly?

CSW_Scoobie

I have used the scoobypedia instructions to do this. I don't have an error code reader. I used this for the how to;

http://www.scoobypedia.co.uk/index.p...eadingECUCodes

And this for the codes:

http://www.scoobypedia.co.uk/index.p...odeDefinitions

I have discounted the 53 error codes, this looks like a common error code to cover a multitude of errors.

Is it that you have never had these codes, or you definatly can't get them? I have a theory that it is all to do with the turbo being just on the threshold of boosting, one sensor telling the ecu to do one thing and the other expecting something else. Does this make sense? if it does is there any way of remapping so that the turbo spools a little earlier or even later?

Thanks

Splitpin

So you're saying that for error code 41, it is giving you four long flashes and 1 short (etc)?

The reality is that there are eight different error states, all relating to the immobiliser, that will/can cause the 53 flash code. If you diagnose the ECU with a Select Monitor you can tell which of the explanations you quoted in post #5 actually caused yours.

The latter. I know how the ECU works - at program execution level, and there is no possible way you can get either 41 or 62, the code to generate those errors simply doesn't exist within the AE800/801/802 ECUs. 41 isn't even in the flash code generator table. 62 is but there's nothing anywhere else in the firmware to actually enable the error bit.

You must therefore be reading the light flash sequence wrong somehow. Aside from anything else, your car doesn't even have an exhaust manifold negative pressure control solenoid - so it's obviously not possible for it to malfunction!

Not really. You certainly can tune/map the car to bring boost in earlier but as things stand it's difficult to work out what's going on with yours given the incongruity with the light flash codes. Need to get some clarity there.

Jolly Green Monster

iTrader: (4)

you need to reset the ecu and wait for the light again and then check it straight away..

you then shouldn't have that many (hopefully lol) have seen the odd code triggered by another but unusual for that many to be logged, I suspect many are old and unrelated to issue

Simon