ECU woes and confusion!

Huddersfield yeah.

Yeah im thinking a trip down, dont want to take the "wee wee" though as you know you have been more than helpful with your "after sales" help!

Im sure it did work before but im pretty confident it has been friend by some mechanic at some point, would explain the general crazy figures we are getting from the ECU.

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Hi,

Just had a quick look. Right, well you are likely biasing the back-emf flyback protection diode for the injector feed, as there is a pn junction between 19 and 20 / 21, so not passive resistance as such. If you are seeing circuit resistance which ever way you connect your meter leads ie reverse them and get the same result, then the protection diode may be fobar. I've just quickly powered up a board, and I see 3.5V on 20/21 on my scope, so within range of what you are measuring, and thinking about it makes sense, as the electronics on the board is doing a check for open circuit injectors, and the 3.5V supply is used to drive a loop current to make that connectivity test / measurement.

So from the above, what you are seeing all looks fine, except possibly the protection diode if you are seeing a low value in both bias directions.

Hope that helps.

Martin

Hi Martin

Thanks for the info, just got back from Lee at RATS and it confirmed our suspicions there is a fault with the ECU, no fuel pump prime.

Is this something you could take a look at Martin? We have had the cover off and there are no obvious signs of anything shorted, or from the signs know which diodes etc to check?

cheers

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Excellent

I will drop you a message for details

The wiring we went off this from the start and everything seemed to make sense

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Hi,

Just had a quick look. Right, well you are likely biasing the back-emf flyback protection diode for the injector feed, as there is a pn junction between 19 and 20 / 21, so not passive resistance as such. If you are seeing circuit resistance which ever way you connect your meter leads ie reverse them and get the same result, then the protection diode may be fobar. I've just quickly powered up a board, and I see 3.5V on 20/21 on my scope, so within range of what you are measuring, and thinking about it makes sense, as the electronics on the board is doing a check for open circuit injectors, and the 3.5V supply is used to drive a loop current to make that connectivity test / measurement.

So from the above, what you are seeing all looks fine, except possibly the protection diode if you are seeing a low value in both bias directions.

Hope that helps.

Martin

Rather a high resistance in just one direction IIRC. Thanks.

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Hi both,

Right got the ecu fine thanks. I'll come back to you in more deail, but firstly the board you have forgetting the case that it has been placed is for a GTA not a R25, so it's a D501 ecu *2102 not a *2103. So you need to match your wiring to that of a GTA turbo, but essentially the major signals are all in the same places.

One of the main ground return pcb tracks is blown out (at least a 2ounce 4mm wide track) as well as a zero ohm link, so will need to look deeper as to the extent of the damage to the power switching semiconductor devices, hoping that it doesn't go further as that would have been a nice whack of current. The track in question disappears under the heat sink, so will need to remove it and see. Will let you know as I have more.

Cheers,
Martin

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Update time...

Dan, right here you go, new base board, electronics modified to change the air temp correction coefficients, and the 12 psi boost cut brick wall disabled. Hence, as a base ecu with no map changes this is going to give you more drivable torque as the ignition roll off is reduced, all the modified Renix 1 ecu's out there from me are thus revised. I have modified the board to allow fitment of a 27128A EPROM’s in a chip converter, thus giving you the capability to make MAP changes and blow them into UV erasable ROMs. The chip fitted has copy of the last factory calibration file 601B to get you up and running initially. I have also included an EPROM burnt with some revisions for you to run on an OE setup (turbo, injectors etc), so as soon as you have a feel for the car with the 601B and have shaken everything down, then swap over and give it a bash. You should also be able to adjust the waste gate up for 12-14psi.

Anyway, pictures below, and I'll get it sent back to you soonest...

Cheers,
Martin

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Just checking - you have the knock sensor connected 31 and 13 (ref), note that the outer shield of the cable goes back to chasis ground pin 2 or 1, not pin 13 as described on the diagram above - translation issue I think.

Regards,
Martin

FLick me that Martins a clever bloke!!!

Ha ha. Isn't that the HSBC dongle cover that I posted you the old chip back in Martin? Perfect snug fit for a EPROM.

.

Hi,

I'm looking for a resistor value (R120) . One resistor is burned, marking isn't reable.
Does someone could check the value please ?

Thx,,
have a good day,

[BIG_MVS]

https://www.youtube.com/watch?v=PdLIerfXuZ4