3.6 check engine light - it's a good thing

[ischmitz]

I highly recommend the check engine light (or some sort of light) to be installed with a 3.6 conversion. (In most DME versions) it allows to flash out the DME fault codes stored in memory. When I checked mine out of curiosity it came up with a fault 1134 (hall sensor, permanent). The hall sensor is needed to run sequential fuel injection and retard individual cylinders once knocking is detected. Without it the DME enters a so-called "limp mode"

After some investigation the DME wiring harness turned out to be the culprit. While the outside appeared undamaged all three wires were ripped clean inside the connector to the dizzy. Real easy fix.

As a result my engine idles much nicer even with a stock chip. When I switch over to the RUF chip it is even better. No more engine stalls with a cold engine under decel. I am not sure about power (yet) but pickup with the engine not at operating temp and decel backfire also improved a lot. All in all the engine behaves a lot nicer.

If it wasn't for the check engine light I would have never noticed that there was anything wrong with the engine.

Ingo

[Moses]

Ingo,
How do you get the check engine light to flash the codes? I have a check engine light and I'm having idle problems.

[ischmitz]

Press the accelerator all the way to the floor. Then turn the ignition switch to ON while keeping the pedal depressed for another 5 seconds. Do not start the engine.

As soon as you release the pedal the light should begin to flash the codes. It starts with one long flash followed by sequences of shorter flashes. It works like this:

0 = long flash
1 = equals short flash

0 1 1 111 1111 would be 1 1 3 4 (hall sensor)
0 1 11111 would be 1 5 (all happy)

Ingo

[Moses]

Thanks!

[Jack Olsen]

Has anyone wired this in to a car not originally equipped with the light?

[Moses]

I'm pretty sure Thom installed a check engine light in order to get a smog certificate. Could be wrong though.

[ischmitz]

Jack,

it all depends on the part number of your DME. If it's the old version 911.xxx you might be out of luck, if it's the 964.xxx version it should work fine.

ROW cars simply did not have the wire running from the DME to the combo instrument installed.

Ingo

[k9handler]

ok Ingo....what's the status on mine? Did you wire up that bit while you were at Haralds? It sounds like a great thing to have working...I just don't know where to look.

[Kroggers]

Bringing back an old thread and hope that Ingo will be kind and reply

Can you give some guidance on how to wire in the check engine light on a 964 engine? I have a spare bulb location on my dash in the SC that I will use.

Is the signal from the DME a normal +12 when the light should come on? Do I just need to run a wire from one of the connectors to the bulb and then to ground?

And what connector and what pin?

Thank you all for the help

[burgundyben]

I'd be keen to know about this too. As I understand it the Patrick 3.6 conversion loom has a wire for this but the Timmins one doesnt.

[Scott R]

Not 100% sure on the 3.6 but most all check engine lights are +12 to the light and the DME grounds the bulb to flash it or light it.

[ischmitz]

Correct - the CEL signal is found on pin 8 of connector T16 which is the 14-pin connector under the drivers' seat. The other side of the bulb needs to be hooked up to +12V (Term. 15).

If your DME has the correct software you can flash out fault codes by keeping the accelerator depressed for more than 3 seconds while turning the ignition to RUN (don't start the engine)

Ingo

[Kroggers]

Cool, thank you Ingo. With the problems I am having at the moment it feels like a good extra thing to install. I will get it in asap.

I will assume that any good +12 will work and I do not have to take it from pin 15 on T16. That way I only need to run one wire from T16 and up to the dash.

I do not have the original chip in the DME, so do not know if the test will work, but will verify that as soon as I can...

[ischmitz]

I saw you got it working. And if it flashes out "bad control unit" that just means the checksum is wrong. (aftermarket chip) so it should also be able to flash out other codes.

[Kroggers]

So with the fact that it only flashes out the code 1141 "aftermarket chip" and nothing else, it means that I have no problems - or does it only flash out one code until it is fixed and then the next?

I also found that the check engine light was on all the time the engine was running today - is this an indication that I have another problem?

[midnight911]

I got 1143. What does it mean?

[ischmitz]

1143 is the error for the tank venting valve - nothing to be concerned about.

Unfortunately, the manual doesn't say anything about flashing out multilple codes. So I don't know if you would only get 1141 (checksum) or other codes as well. And the CEL stays on with code 1141, that I know for a fact.

ingo

[ToddM]

Works on my 3.6 SC conversion (which has the light since it's CA street/smog legal), where can we find a lit of the codes?

[Kroggers]

Originally Posted by ischmitz

Unfortunately, the manual doesn't say anything about flashing out multilple codes. So I don't know if you would only get 1141 (checksum) or other codes as well. And the CEL stays on with code 1141, that I know for a fact.

ingo

Thank you Ingo, so if I want to use the CEL I need to find a way to clear the 1141 error it is throwing up - any idea how I do that, or should I just disconnect the light?

I think I will try to wire in the OBD1 connector I have as well soon - that way I can read the DME codes properly...

[ischmitz]

The only way to get rid of that code is to change to the stock chip or modify the check sum on your chip (read out, erase, reprogram)