ambetone
09-09-2009, 03:19 PM
Hi all, I'm a new member and I thought I'd like to contribute to this forum. I own a 99 KH 3.5, my second Mitsubishi after a 96 KS Verada. I have been a car audio and alarm installer for 25 years and many of those on Mitsubishi Magna and Verada.
A common issue I've come across over the years is do you fit an upgrade alarm or a new (stand alone) alarm on a KH (or similar) series Magna with a factory fitted Australian Arrow (Yazaki) body control unit? Keep in mind the BCM in my KH is a: TH8-K46.
Normally I would always say to keep your factory remotes and fit an upgrade alarm but in this case I differ. Although the BCM is an excellent unit the factory remotes are close the worst rubbish I've seen. Apart from aweful button design a common failure cause is the battery cage breaking away from the circuit board due to poor quality design and / or manufacture.
The body control unit (BCM) controls a few functions in this vehicle including the factory fitted alarm. The alarm is designed to sound the horn if a door, tail gate or bonnet is opened without either using the factory remote or key to open the vehicle.
This is where upgrading becomes a trade off as many vehicles have little idiosyncracies that can cause problems. As an example the Mazda 929 BCM unit needs one arm input, two disarm inputs and if you lock / unlock a second time WITHOUT opening a door the second lock input will disable the factory alarm. (leaving the vehicle unprotected) This is the sort of issue faced by alarm fitters when deciding which way to go.
Enter the KH series body control module, as yet I am unable to find any reason not to replace the factory remotes with aftermarket remotes and keep the factory alarm functionality. The software set in the KH is perfect for remote replacement. Here's how to do it.
A warning here, if you do not have the skills to do this seek the help of a qualified fitter.
All the inputs you need are at the BCM located to the right of the steering column after the lower dash removal. There are three plugs (connectors) to the BCM which I will refer to as Small, Medium and Large.
The first thing that is important is that many of the inputs are logic level (5V) and not the usual 12v or ground type. While in my experience this will not be an issue with a keyless entry unit it can be a problem with SOME alarms. Some alarms cannot tell the difference between 5v and earth at input level (they see anything below six volts as ground) For this reason a keyless entry unit is a better choice over an alarm unit.
The factory alarm works by arming with either a key lock input or a remote lock input. Disarm is the same. It triggers if a thief (for example) breaks the glass then opens the paddle lock therefore not using a key / remote to correctly disarm the factory alarm.
Here are the wiring input/ outputs we will use:
Constant 12v ... Red ... Large plug
Earth ... Black ... Large plug
Ignition ... Black / White ... Large plug
Left indicator ... Green / Black ... Large plug
Right indicator ... Green / Yellow ... Large plug
Lock input ... Blue ... Medium plug
Unlock input ... Red / Green ... Medium plug
Door trigger ... Green / Red ... Medium plug
Bonnet trigger ... Brown ... Medium plug
Most of these connections will be common sense but if you are unsure you need to seek the services of a professional alarm installer.
The lock / unlock trigger points are critical, there are actually about six points that will mimic these wires I have provided but these are the only two which will allow the factory alarm to function as intended.
The Green / Red door trigger at the BCM is the common input, from there the BCM will control the light via the secondary control unit in the fuse box. A common alarm connection for the door trigger is the two pin plug at the top of the fuse box (red wire / red & white wire). You CAN use this input but keep in mind that if the alarm / keyless unit you are using has “door open” warning function then using this wire will trigger it every time as the BCM provides a courtesy light extension function. There is also a second yellow wire which only works with the drivers door, this is the input which provides the “key in ignition / headlights on” warning upon exit. Don't use it.
The Brown bonnet trigger wire can also be use as a trigger for shock sensors etc. Remember that if you use more than one sensor on this negative trigger they MUST be diode isolated so the sensors cannot “see” each other, if you do not know how to do this please use an alarm installer.
This is THE car to upgrade the factory remotes, I've never seen better. Have fun.
Rod
A common issue I've come across over the years is do you fit an upgrade alarm or a new (stand alone) alarm on a KH (or similar) series Magna with a factory fitted Australian Arrow (Yazaki) body control unit? Keep in mind the BCM in my KH is a: TH8-K46.
Normally I would always say to keep your factory remotes and fit an upgrade alarm but in this case I differ. Although the BCM is an excellent unit the factory remotes are close the worst rubbish I've seen. Apart from aweful button design a common failure cause is the battery cage breaking away from the circuit board due to poor quality design and / or manufacture.
The body control unit (BCM) controls a few functions in this vehicle including the factory fitted alarm. The alarm is designed to sound the horn if a door, tail gate or bonnet is opened without either using the factory remote or key to open the vehicle.
This is where upgrading becomes a trade off as many vehicles have little idiosyncracies that can cause problems. As an example the Mazda 929 BCM unit needs one arm input, two disarm inputs and if you lock / unlock a second time WITHOUT opening a door the second lock input will disable the factory alarm. (leaving the vehicle unprotected) This is the sort of issue faced by alarm fitters when deciding which way to go.
Enter the KH series body control module, as yet I am unable to find any reason not to replace the factory remotes with aftermarket remotes and keep the factory alarm functionality. The software set in the KH is perfect for remote replacement. Here's how to do it.
A warning here, if you do not have the skills to do this seek the help of a qualified fitter.
All the inputs you need are at the BCM located to the right of the steering column after the lower dash removal. There are three plugs (connectors) to the BCM which I will refer to as Small, Medium and Large.
The first thing that is important is that many of the inputs are logic level (5V) and not the usual 12v or ground type. While in my experience this will not be an issue with a keyless entry unit it can be a problem with SOME alarms. Some alarms cannot tell the difference between 5v and earth at input level (they see anything below six volts as ground) For this reason a keyless entry unit is a better choice over an alarm unit.
The factory alarm works by arming with either a key lock input or a remote lock input. Disarm is the same. It triggers if a thief (for example) breaks the glass then opens the paddle lock therefore not using a key / remote to correctly disarm the factory alarm.
Here are the wiring input/ outputs we will use:
Constant 12v ... Red ... Large plug
Earth ... Black ... Large plug
Ignition ... Black / White ... Large plug
Left indicator ... Green / Black ... Large plug
Right indicator ... Green / Yellow ... Large plug
Lock input ... Blue ... Medium plug
Unlock input ... Red / Green ... Medium plug
Door trigger ... Green / Red ... Medium plug
Bonnet trigger ... Brown ... Medium plug
Most of these connections will be common sense but if you are unsure you need to seek the services of a professional alarm installer.
The lock / unlock trigger points are critical, there are actually about six points that will mimic these wires I have provided but these are the only two which will allow the factory alarm to function as intended.
The Green / Red door trigger at the BCM is the common input, from there the BCM will control the light via the secondary control unit in the fuse box. A common alarm connection for the door trigger is the two pin plug at the top of the fuse box (red wire / red & white wire). You CAN use this input but keep in mind that if the alarm / keyless unit you are using has “door open” warning function then using this wire will trigger it every time as the BCM provides a courtesy light extension function. There is also a second yellow wire which only works with the drivers door, this is the input which provides the “key in ignition / headlights on” warning upon exit. Don't use it.
The Brown bonnet trigger wire can also be use as a trigger for shock sensors etc. Remember that if you use more than one sensor on this negative trigger they MUST be diode isolated so the sensors cannot “see” each other, if you do not know how to do this please use an alarm installer.
This is THE car to upgrade the factory remotes, I've never seen better. Have fun.
Rod