Code 31: Theft deterrent signal missing

[StockoVRWagz]

Did a search, got literally everyinthg besides code 31,
I let a well known Auto place put an alarm in my car about a year ago, 6 months after that the alarm died, its under warranty but I really dont want them touching the car again unless its absolutely nessersary. (which I bet ill have to as the alarm has completely f'ed up)

What would I look at first that made the car throw this error code? It never had the code come up last time I checked it and that was while the alarm was dead as well. Is there specific wires under the dash/engine bay I should look at that may have come loose or have been broken?

Cheers.

 

[Boonz]

you need a 1 piece key reader thats around your ignition barrell, it doesnt make contact with the keyhead when turning the ignition and sets the code........ can also stop your car from starting

usualy the keyhead and reader need to be replaced at the same time

 

[StockoVRWagz]

ahhh ok, thanks
Ive had no problems starting the car at all, the key is loose from the plastic head as one screw is missing, could this cause what you are saying?

 

[Chirpstr]

ahhh ok, thanks
Ive had no problems starting the car at all, the key is loose from the plastic head as one screw is missing, could this cause what you are saying?

Yes, one of the screws needs to be there for the battery in keyhead to obtain earth. It could be the problem.

 

[OzJD]

I've posted this a few times lately...

This sounds like a little more than a dead remote battery to me

THEFT DETERRENT SIGNAL

To Test - Code 31
When the ignition is switched On, the ECU sends a signal to the BCM (body control module) or the TDM (theft deterrent module) to confirm that the correct ignition key has been used. When the BCM or TDM receives this signal, it permits operation of the starter motor and returns a signal to the ECU allowing operation of the fuel injectors.
The ECU will set code 31 if the BCM or TDM does not return a signal to the ECU to permit operation of the injectors. If the BCM or TDM does not receive a signal from the ECU when the the ignition is switched On, there will be a one second delay in operation of the starter motor after the ignition key is moved to the start position.
(1) Clear the fault code as previously described
(2) Attempt to start the vehicle. If there is a one second delay before the starter motor operates, proceed to operation (3)
If the starter motor operates as soon as the ignition key is moved to the Start position, an intermittent fault is indicated. Check all wiring and connections between the ECU connector terminal A8 (M/T), or teminal C11 (A/T) and the TDM or BCM.
(3) Switch the ignition On and check that there is 4-6 volts at the diagnosis connector terminal 9
(4) If 4-6 volts is not available, check the wiring between the diagnosis connector, the ECU connector terminal A8 (M/T), or terminal C11 (A/T) and the TDM or BCM for a short to earth or an open circuit. If no fault can be found with the wiring, renew the ECU.
(5) If 4-6 volts is available, a fault in the theft deterrent system is indicated. Refer the vehicle to an authorised dealer.

 

[StockoVRWagz]

Thanks for that, I remember seeing it a while ago and I tried searching for it, the only code 31 info I found was on page 6 or 7.

It must be an intermittent problem, I bet when the place did my alarm they stuffed it lol