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Ok, here we go again, I've just purchased another P38 to join my fleet of P38s. She is a very late 2001 Vogue. The seller advised the only fault is a mysterious battery drain, 'easy I thought' I know all the answers to this. Ok so she won't go to sleep after locking her and waiting for 2 minutes. It's not the RF receiver as the aerial has been disconnected. It's also not the BECM as I've had this refurbished by a well known P38 specialist. I actually have another identical P38 so have swopped the BECMs, RF receivers and ultrasonic sensor over to rule them all out. I've also replaced both front door locking mechanisms. As you can see I've done the obvious things but she just will not sleep...... What next? The only fault with car is the sunroof is stuck in the closed position due to a seized cable so will not set and shows 'open' on dash. My other P38s sleep fine with sunroof open so again have ruled this out. Where do I go next?

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Do you have a copy of the BeCM SID? pages 10-15 give a list of all the inputs that will keep a BeCM awake and a checking flowchart.

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No I don't, could you send?

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Try here https://drive.google.com/file/d/1bYljTTLbcRvp6wLJ-3qxhWPEhr4agC-G/view?usp=sharing

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If you go into the BeCM settings with a Nano, you can disable the sunroof so the message will disappear.

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I've only got a Hawkeye Total, would this work?

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H&H Lucky You about the Hawkeye, of course it could be done with it.

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Should do. On the Nanocom you look under the BeCM settings and it shows what is fitted and what isn't (things like front fogs, cruise control, sunroof, etc) and you set sunroof to Disabled so it no longer beeps and tells you it is unset.

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Ok, good news, using the BECM SID, I removed plugs individually from the BECM in order as indicated on the 'active imputs' did the usual trick of then locking the door and waiting 2 minutes to see if the BECM went to sleep. After a unplugging and plugging them in order eventually with plug C362 unplugged the car finally went to sleep. (SID shows this is the rear left door however it operated the front left door in my car?). Question now is where does the fault lie as I've already replaced this lock once from another car, two dodgy locks....... Should I be looking at wiring / plugs or something else?

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Just deleted a couple of my posts where I'd completely confused myself. C362 connects to both front and rear left side windows (not door latches), so via the outstation in the front door and direct to the rear door. Does the left rear electric window switch work?

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From my understanding it's plug C362 (front, bottom row, 2nd from left (black)). Tried test with sunroof motor unplugged and test failed so fault must be another input through that plug?

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That's C362, and the only things the SID says on that connector that can keep the BeCM awake are the left rear door being open or a signal from the ultrasonic sensor.

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I've swopped the ultrasonic alarm sensor over with a known good one and there is no dash error saying any doors are open when I lock it? Still seems strange that the plug isolates the locking function to the front passenger door? Certainly narrowing down the fault.

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It carries the data line to the LH front door outstation so it will affect the locking function. Although that doesn't seem to be relevant as far as the BeCM sleeping or not is concerned.

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In case you have missed something, here is the BeCM sleep test wording from my diagnostics help pages:-

  1. Sit in the vehicle in the driver seat with all the doors closed.
  2. Wait until the interior light switches off.
  3. Switch on the ignition.
  4. Switch off the ignition.
  5. Open the driver door and leave the door open for the reminder of the test.
  6. Switch off the interior lights by pressing the button for 4 seconds. On the message centre you can observer the message "Lights off".
  7. The message centre displays "Ignition key in" for approximately 2 minutes.
  8. If the display goes blank after the two minutes, then the BECM is gone to sleep, if the display is still on, then the BECM did not go to sleep.
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David, Many thanks, I'm aware of this way of testing as well. The problem is she just refuses to sleep unless you pull plug C362.

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C362 (up to 99MY) C1286 (from 99MY) 16 pin black

1 LH front door serial data bus (data)
2 LH rear window anti-trap 2
3 LH front window anti-trap 2
4 LH rear door open
5 LH rear window anti-trap 1
6 Movement detected (by volumetric sensor)
7 LH rear window down
8 LH door mirror position
9 LH front door serial data bus (direction)
10 LH front door serial data bus (clock)
11 LH front window anti-trap 1
12 and 13 Not used
14 LH rear window up
15 Volumetric sensor power supply
16 LH rear window anti-trap power supply

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and it's time for bed..... Went over this afternoon to give Phil a hand and see if we could work out the problem. He'd tried his Haweye and it wouldn't wake up so I tried my Nanocom and that wouldn't either. OBD socket was a bit green but not too bad. Checked Fuse 33 that supplies power to the OBD socket and found it was blown. Replaced that and the Nano fired up. Started checking things and noticed something odd. With the left front door shut, the input to the BeCM from the door ajar switch showed it to be open. Open the door and it still showed as open. However, what was really weird was that the interior lights were working as they should from that door. When Phil had got the car the left front door was superlocked so he'd replaced the door latch so that was known to be good. So the only thing between the latch and the BeCM was the door outstation. Stole one from Phil's other P38, put that in and the Nano reported a change of state when the door was opened or closed. Closed all the doors, locked the car, waited 2 minutes and it went to sleep.

So, although everything appeared to be fine and was working, for some reason the LH front door outstation was telling the BeCM that the door was open although it wasn't......

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My god that's good service. We should all have you on speed dial ...... "dial-a-mod" or put in a bat phone?

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It was slinging it down with rain and I had two jobs I wanted to do but both were outside so it was a choice of sitting in the house getting bored, get soaked working outside or take a 35 minute drive over to Phil's and see if we could find his problem. So I chose the latter......

He's still got one problem, even after getting the OBD socket working, his Hawkeye appeared to connect but the BeCM settings were French, LHD, GEMS (it's a Thor), manual (it's an auto), etc, all the usual signs of not connecting properly, even though my Nanocom showed everything correctly. First time I've even seen a Hawkeye though so couldn't really help with that.