Hi guys,

I have a B2515 DTC that is set on the car and I am trying to pinpoint the issue.

I have the column lock motor in front of me and with the Tech2 commanded the SCLM to lock and then unlock but it hasn't changed anything: the pin remains in an unlocked position.

I tested the resistance between terminal A and B of the lock and it is at 300 ohms, which is the open lock position resistance.

In my mind there are two possibilities, the lock itself is fried or the relay in the SCLM that commands the motor of the lock is fried.

My current thought to eliminate doubt is to see if I can manually lock the column lock. In order to do that I was thinking of applying Vs to pin D and ground to pin C. This should get the motor to lock.

Now before doing that I need to know if the motor is 12V or 5V or something else motor because if I apply 12 to the motor and it isn't a 12V motor, it will burn.

My alternative is to build a small circuit that will simulate the column lock system from the SCLM point of view as it appears to be a very simple piece of equipment. However before going about doing that I want to pinpoint the issue.

So does anyone know before I go about tearing things apart and getting frustrated?



a++ Cedric

ps: For those who wish, you will this info at 11-307, 15-33 for the schematics and 15-39 for the DTC in the helms manual.

 

Have you checked at terminals a&b with (lock unplugged from column) with a digital voltmeter and tch2 commanding unlock if you have any voltage there???


Ron

 

Hi Ron,

According to the schematics I have regarding the terminals:

A - Steering column lock signal
B - Ground
C - SC unlock
D - SC lock.

To answer your question, the voltage between A and B is 5V. My understanding is that A-B connectivity is a position sensor. Unlocked resistance is 294 ohms, locked position is 487 ohms.

I do not see any voltage between C and D, terminals used to command the motor. A-B being 5V doesn't necessarily mean that C-D is 5V also; as A-B is a sensor, therefore no power required whereas C-D is a command link as may require more voltage.

When I command the Tech2 there is no variation in C/D nor C against ground or D against ground. That being said, there may be a protection in the SCLM that ignores the Tech2 command is no resistance is encountered on the A-C link - which is the case when I put the voltmeter.

My current thought is to put a resistance on A-B link and flip it when I start the car up to see what happens.

Make sense?

a++ Cedric

 

Problem located: it's the SCLM.

The column lock device is functioning as it should when applying an autonomous voltage.

I took the lock device apart, it's actually a pretty simple mechanism, an electric motor with a switch button used as a position sensor.

a++ Cedric