75ZT Community

Morning.
just a quick question. I have a customer with a ZS that has come in with no hazards. As it is an 04MY that was easy. Momentary switches weren't enabled via ZCS codes. However, when he sent me the current configuration, it was all wrong totally. according to the current ZCS the car is a diesel!It's not, it is a 1.8 petrol. Now, he has since told be there are at least two spare scu's laying in the customers car so someone may have been "playing".

Now for the strange bit. When I sent him the new ZCS codes they went in, hazards work, car runs as sweet as a nut. However, The SA string data is not being retained. GM and VN no problem. So without the SA string being retained T4 (Testbook version 4.Computer Diagnostic System) is showing 12 fault codes continually.

The question is.....which ecu holds the master data for the SA string.
Engine ecu, SCU or SRS (Supplementary Restraint System) ecu??

Any help or advise gratefully received.

Cheers

Stu

I'm not 100% sure, but I would say the SCU holds the backup. Although it should update when the codes are changed. Is there a VIN (Vehicle Identification Number) mismatch, or other erraneous matches, mileage etc...?

What has the customer been doing? Have they bought a scrap ECU (Engine Control Unit) and/or SCU and fitted them to the car? Sounds like they have, and the differing ZCS codes from the original has altered the car options. Is it a diesel ecu in the 1.8, or a 1.8 ecu thinking its a diesel?

One possible option is the customer had problems connecting the car to a T4 after data corruption on the ECU, or has used the wrong disc in the T4. The T4 user would have been prompted for ZCS codes and the user could have made them up from differing spec'd cars, plenty of people will generate checksums no questions asked. My first thoughts are the SCU and ECU have been swapped out causing the errors.

Yeah, I am of the same opinion. Somewhere we have an ecu mismatch me thinks.
trouble is, dealer who now has the car has no idea what has been done elsewhere previously.
I will get him to check the ecu I think as he has fitted a new scu I believe.

Will let you know how we get on.

Cheers

If a new SCU has been put in, it will have re-learnt the wrong data from the ECU, and now be married to the ECU via the security code. If an old ECU has beed used, then you could probably do with finding out why, and where the old SCU and ECU has gone.

Remember the days when it was either the plugs, lead, condensor, points or the fuel pump.

No I asm not a Luddite - I also remember the fuel consumption in those days

Paul

cracked it !
I put a 4 in column 3 of the SA data telling the scu it was diesel EOBD and recalculated the checksum and it solved it.

No idea why !
Still, car is now sweet and customer can have it back.

Jobs a good un !
Thanks

Stu

Mystery solved! So did it have the correct ECU, or is it continuing to function with a diesel?

it was the original and correct petrol ecu believe it or not.
I have put that one down as one of lifes little mysteries.

How curious! I wonder what they've been up to on the car! Certainly one to note for the next occurance