Followup info on no start...

[bwh13]

The fault code is blinking a 1281, Bentley says it is a "check voltage supply from battery to DME control module" code. If the main relay is getting voltage when the key is in 'run' position, doesn't this mean the DME is 'alive' and getting voltage?

[PiercedE30]

The power for the main relay comes from the distribution block, aka the positive lug on the passenger side which is always hot. The relay should click on when the ECU gets power. Make sure the relay is good. Grab some alligator clips and ground the relay itself and make sure it click when you give it power. Same with the fuel pump relay. Check the basics. Also, make sure you are getting a good 12v on the green power wire at the X20/C101 and at the ECU.

[bwh13]

The main relay does click when key is turned to 'on' position. Fuel pump relay does not. I swapped the fuel pump relay with another relay and still no click.

Where can I check power at ECU?

[Fidhle007]

Doesn't the ECU need a separate power source outside of what the harness provides or does Treehouse take car of that with their adapter?

[btec116]

Power to the ECU is supplied through the (only) harness connector to it.

THats odd with the fuel pump relay though. If it were EWS, neither should work (so thats a good thing). Dodgy relay? Also check if theres power going to the relay. By memory they should be the same relays (they are on the M52), try swapping the main and fuel relays. Then you'll know for sure where the problem is (wiring, or relay)

Do I remember someone else having similar fuel-pump-dead problems ages ago? I seem to remember reading about this before my swap (~3-4 months ago??)

[btec116]

The main relay does click when key is turned to 'on' position. Fuel pump relay does not. I swapped the fuel pump relay with another relay and still no click.

If your ECU had no power, your ICV would be dead. But like PiercedE30 says, its still important to check you're getting a GOOD supply voltage. Any chance some of those connectors are dodgy? This can really f*ck with your DME; if problems persist consult your adapter!

Where can I check power at ECU?

Come on!!!

[btec116]

Oh, sorry, just realised you bought the adapter. That'd make sense then.
Your X20/C101 are the two connectors that dont fit together between motor and harness. Thats why you have your Adapter. One of those pins carries power through all them connectors to your ECU. Its a big fat green one (I beleive thats the engineering term;)
Cant remember what pin number/s but you can find that very easily through these pages. Should be pretty obvious once you get into there anyway.
Unless someone else cares to point it out?

[bwh13]

Checked the fat grreen wire and it appears to be in the correct place in both connectors, so the ECU is getting voltage. The coils get voltage with key 'on'...but still get the 1281 code.

[btec116]

Lets back up a bit.

1. What ECU? I'm not sure (not my setup) but AFAIK there are two 413's, one with EWS and one without (I think red and grey label respectively). If no EWS, then no probs. If it does have EWS, is it disabled??? Ie, is your AA chip actually an EWS-delete?

2. Going off the Bentley explanation of your fault code (which may be incorrect); "Check voltage supply to DME" -did you check this? So, besides the wires being in the right place, did you check if they are getting supply voltages? Again, depending on what this (1281) signal means, there might be no power getting TO the ECU, or it might just not be sending signals out (ie, EWS active).

3. Spark: Are you getting spark??? What do you mean the coils get voltage? How do you know this? If you are priming your fuel rail, and there is STILL no fire, there is either no spark, or your injectors may not be opening.

4. Fuel pump relay. There is obviously power getting to the relay (since you can short it). So, the relay is not being switched. Why? The signal to switch the relay should originally come from the ECU. First see if there is a voltage difference between the switching terminals at the relay plug for key-on. Since you already checked the relays, we'll assume they are working. If there is no signal, track these wires back to the harness connectors, check again for voltage through them. Now you should have an idea if you are getting a "fuel pump on" message from your ECU or not. If you ARE, then there may be a problem somewhere further up the line towards the fuel pump. If you are NOT, then it seems the signal is not leaving the ECU (go to 5).

5. If the ECU is not sending a signal; Why? Is it ON? Unplug the harness connector to the ECU, check if there is power getting to the ECU (by shorting the power supply pin in your harness connector to ground while key-on). If you are sure your ECU is getting a supply voltage, check if the ground pins ARE actually grounded (ie, check for continuity). If its getting a voltage, and has a good ground, it should be working, or else its dead (very unlikely). The fact that your ICV is buzzing is a pretty good sign that your ECU is active!

ANyway, from everything you've said, it seems like there is no signal going to your fuel pump, and I'm not sure you are actually getting spark. If you have EWS it is VERY likely this is the problem. If you dont.... well, do all these checks and you'll know more.

Some things you obviousy need to have to do this:
* A mutimeter
* ETM -would be VERY helpful, this is a reliable technical document, not second-hand info such as your Bentley. There is a breakdown of the pins in the Bentley as well, but I found some incinsistencies between that and the ETMs. So dont (ever) beleive everything you read!

I went through and identified all 88 pins of my harness connector, then wired up (made my own adapter) and started it first time. Although this took a while, that way you know exactly if you have a problem, and dont have to work backwards (blind) through your wiring.

The other thing is, there may be faults in your adapter. Check all the pins for continuity, move the wires around a bit, you might find something. Not sure about the ready-made adapters, maybe some wires are slipping out of the pins, maybe they weren't crimped properly, etc. If you don't know, assume it's faulty.

If anything here wasn't clear, or if you still dont know what the problem is, let us know.
Good luck!

[bwh13]

It is a 413 red label ECU, when I bought it from a forum for sale ad I asked about the EWS disable and was told the AA chip would take care of that, but maybe that's what it is.

I hate to say it, but now I'm wondering why the 413 Red label would have the EWS. Isn't the Red label the one without EWS?

If the ECU is sending a signal to the ICV, but not to the pump relay or the coils, that seems to indicate the EWS has not been disabled, as it should be.

I checked all the wires in the adapter harness and they appear to be in good shape, no loose wires etc.

I dropped the ECU off at a local BMW shop and they said they could plug it into one of their OBD1 cars to see if it will run. Should know in a day or so.

[btec116]

Sounds alot like EWS... Cant remember which 413 is which though. Well, time will tell!

[shopkeep]

Yeah I am hoping it is the EWS for mine as well...still dont have the money to order the chip...will very soon though.

The 413 with EWS was made in 1995

[bwh13]

OK the shop couldn't get their car started with the ECU either, so apparently that's it. Sending it back to whom I bought it from to get it swapped for a good one...

I checked voltage going into the ECU at the connector and it all seems to be good, checked all the grounds and they seem good as well...

[shopkeep]

aww, you have me worried now. The guy that I got my ECU from also put in the random chip that's in there...from the looks of it he scratched the mainboard trying to pry the ECU open...very worried now :( It could still be your chip though right? did they check that?

[e30pq]

I received the same code when I first installed my S50. I added a second engine ground and it cleared.

I originally had one engine ground on the drivers side of the motor, I added the second one on the passenger side of the motor.