M35 Dtc Code 1805

[iamhe77]

Body Control Module

[chad bob]

Well I'm going to do a handstand and climb into the drivers footwell with a torch. Going to have a look see at what switches are connected to the brake and what they might do.

[andynogo]

Umm, I know I'm a bit Jonny-come-lately, but, which wire is it that people are cutting/switching? Sounds like something I need to do.

[Commsman]

Umm, I know I'm a bit Jonny-come-lately, but, which wire is it that people are cutting/switching? Sounds like something I need to do.

Yeah Andy, you do! Everyone with a M35 should do this. Then crossing a busy road won't require such a big gap.

It's pin 55 on the ECU, but run it via a switch so you can "cut" the wire at will (& reconnect it also). If the ECU doesn't see the brake switch every so often (days normally) it will eventually throw a code. Good news is the code disappears if you switch the wire back into circuit & put your foot on the brake.

For more info have a read of this thread from about here (or even a few pages before -it's very interesting): http://www.skylinesa...ost__p__5832870

Edited August 4, 2011 by Commsman

[andynogo]

Thanks Leon, helpful as always!

[scotty nm35]

I found out today, after months driving with the wire cut, it will eventually go into throttle limp. I was driving when I suddenly noticed the throttle wouldn't go past 24% on the informeter. A quick roadside ecu reset didn't clear it, unplugging the ecu did as I couldn't get to the wires.

I have a switch in the dash now...

[ironpaw]

Interesting....so even emanage users need one put on too...

[scotty nm35]

I assume so, unless the limp mode was caused by something else. I have been stuffing around with the home and end stop adjusters inside the throttle...

[jasevr4]

I'm getting DTC 1805. In theory once you flick the switch and press the brake does it go away? Or do you need to clear the code?

[Dunc]

I'm getting DTC 1805. In theory once you flick the switch and press the brake does it go away? Or do you need to clear the code?

If its like other error codes Ive experienced in the M35 (eg dead AFM) the code wont clear automatically when the problem is resolved (ie plug the new AFM in and its still showing you a CEL - but the car is operating fine). If its no longer in limp mode, I would suggest that it will self clear over the next couple of days; but if you're feeling pedantic you can clear the codes manually

[jasevr4]

Funny thing is that I haven't noticed a drop in power, although I wasn't giving it much this morning. Better take it for a drive at lunch and see what's up.

[Dunc]

Funny thing is that I haven't noticed a drop in power, although I wasn't giving it much this morning. Better take it for a drive at lunch and see what's up.

If the limp mode caused by the wire cut is the same as the one with a blown AFM you'd definitely notice, even when not giving it much. Basically theres a ~2100 RPM rev limiter in place and it bounces off that once when you try and move your foot much more than 1/4" on the pedal.

[jasevr4]

If the limp mode caused by the wire cut is the same as the one with a blown AFM you'd definitely notice, even when not giving it much. Basically theres a ~2100 RPM rev limiter in place and it bounces off that once when you try and move your foot much more than 1/4" on the pedal.

Pure weirdness then. I'm sure it's 1805 but I would have revved it higher than 2100 RPM this morning. I know I was tired this morning but surely not that much!

[scotty nm35]

If its the wire cut you just have to reconnect the wire and press the brake, you will be good for another few months. If you leave it the car will go into limp mode eventually and limit the throttle.

[Dunc]

If its the wire cut you just have to reconnect the wire and press the brake, you will be good for another few months. If you leave it the car will go into limp mode eventually and limit the throttle.

I just read Andys first post in this thread, he suggested that the limp mode imposed was that "Under hard acceleration = reduced response" which is a bit different to the rev limited limp mode. So, given how tired you were Jase you mightnt have noticed but as Scotty said - flick that switch you put in and see if it seems normal now?

[Commsman]

I just read Andys first post in this thread, he suggested that the limp mode imposed was that "Under hard acceleration = reduced response" which is a bit different to the rev limited limp mode. So, given how tired you were Jase you mightnt have noticed but as Scotty said - flick that switch you put in and see if it seems normal now?

The above could be true as in my experience when the light came on (from the brake wire cut) I didn't notice any drop in performance or rev limit being imposed, but I also wasn't doing anything considered 'hard acceleration'. As for resetting the code, for me it was as simple as flicking the switch back to normal & pressing the brake pedal. Maybe it is different if the MIL has been on for a long time.... Also, I don't know how Scotty got a months driving between resetting. I got about 500km before my light came on.

Edit: just thinking about this - it's probably because Scotty has a light on permanently due to the Emanage. He is probably talking about a proper limp mode, which is quite on the cards if left for an extended period.

Edited January 4, 2012 by Commsman

[zei20l]

i found that i needed to reconnect the wire and hold the brake pedal on for at least 5 seconds for the light to clear..........

[jasevr4]

I'm thinking my wiring is shithouse...

[Commsman]

^lol.

It's just 12V that needs to be applied to the ECU pin to clear the code. Can get it from anywhere. Of course if you don't use the original brake wire & switch in some permanent 12V, you'll have restricted throttle all the time.

I'm starting to think of a good idea for a "valet mode"....

[dasic1]

Yeah I get coming on around every 500km. Ive never noticed any difference, but its usually when im just cruising along so just press the brake slightly with my left foot while holding the button and the light goes out after a couple of seconds