vr bcm fault?

[markovr]

My body control module wont flash the indicators when you lock the car with the keyhead.It flashes twice when you unlock it ok so the indicator/bulb circuit is fine.
I wouldnt care but it uses that input to trigger the alarm upgrade I fitted a few years ago to arm so it doesnt work either.
Tried 2 other same level and part number bcms but they all wont flash the indicators...surely they all cant be faulty?...must be something else on the car...any ideas?

 

[jc58nc]

Try disconnecting the alarm upgrade and see if it flashes then.

 

[markovr]

Try disconnecting the alarm upgrade and see if it flashes then.

Yep did that ....no joy even disconnected the l/h feed wire(its the trigger wire to the alarm) from the bcm so only the r/h would flash.
The last time I tried a different bcm it was disconnected so its nothing that to do with the alarm that is blowing something up in the bcm as you connect it for the first time.
The flash circuit to the indicators is a simple power feed switched across a relay contact ...only the relay is controlled by the electronics in the bcm.Theres no influence on the bcm by whats on the end of the indicator circuit since its electically isolated.

 

[jc58nc]

Could be your key remote with a faulty lock button?
Do you have a spare to try?

No sorry you mentioned you tried other BCMs, you would have had to have their key remotes to use them.

 

[markovr]

The two different remotes had keys with them ..both were one button type and they all did the same thing.....the door locks go down and everything locks so it is getting the signal from the keyhead ok

 

[jc58nc]

I can only suggest try your BCM in another car or borrow a BCM from a car that you know it was working OK.
Also check the wattage of the indicator globes, higher wattage may upset the BCM when it gives out the "one" flash but OK on 2 flashes.

 

[markovr]

Yep thats a idea...but I dont know anyone who has one close but Ill keep looking...the bulbs shouldnt make a difference as the circuit is a power to a relay contact and the other side out to the pos side of the lamp...and theres only one side connected anyway...but thanks for your interest ..when I find out what is causing this Ill post it up

 

[NickVR]

on my vr the left side wouldn't flash on locking but everything would arm. went back to autobarn (thats where my aftermarket alarm came from) and told them that i think that the alarm has stuffed it up, but the guy said that they don't run power from the bcm to the alarm just use a signal feed. i thought he didn't know what he was talking about because to get a signal of some sort you need power. any way went to peter page holden and got them to check it. they looked at it and they were gunna give up but they took it to an auto electrician and found a one way diode ( only allows power to flow one way) fitted to the indicator flash wire had stuffed up and replaced it. so see if any diodes that run to the alarm or indicator flash wires need replacing. if not see an auto electrician. good luck.

 

[Doctor Bob]

nicks idea stands to reason, the output that is pulsed is the same circuit so it really has to be related to the aftermarket thing

Rob

 

[jc58nc]

One other point I just picked up on while reading about BCMs and key readers is if any of your doors aren't shut properly (earth signal from a door switch) the indicators will not flash to alarm the driver that the car doors are not secure. Could be an earth fault?