Burnt PCB fuse trace in door lock module (1 Viewer)

[snoop]

I found the troubleshooting guide in the FSM but I was wondering if schematics exist for sub system components such as the door lock module. I popped open my module and found it to be very serviceable but I also found a burnt fuse on the board that I can re-solder but it would be nice to know what part of the circuit that stopped working.

 

[bigredmachine]

typically they are not serviceable as per Toyota so I don't think that youll find a schematic for that. best way to figure out whats not working with the burnt fuse is to try all the switches and see what dosnt work

 

[Haspin FJ]

I had this happen to two modules. wound up being the harness in the driver's kick panel was not totally clicked together and causing a short. Just an idea to check the harnesses in that area for corrosion as well which is typical from windshield leaks and could cause the same effect.

 

[Pin_Head]

It appears to be a low value (like .001 ohm of less) resistor. If the resistance didn’t matter, it would just connect directly to the ground plane like any other low impedance connection.

 

[ppc]

.001 ohm ? Check your multiplier

 

[george_tlc]

Yeah, at least 10x that resistance. It's basically copper trace that has been configured for a certain track width and length (hence the wiggle) to create a fusible link. Obviously intended as a desperate last measure - or toyota wants you to buy new modules all the time.'

https://www.eeweb.com/tools/trace-resistance

Lets you get an idea of the resistance value if you can measure the track width (calipers) and guesstimate the length of the trace. Likely 1oz copper for the PCB. Though it's the fusing current of the trace that is important in this case, not the resistance as such.

1st step, figure out what is causing the short that is blowing the trace. Then repair, I'd guess a strand or two of thin multi-strand wire would be 'good' enough (just insulate it).

cheers,
george.

 

[snoop]

@Haspin FJ there is a little corrosion, i pulled off the door panel and found this module just hanging in the pan of the door. there appears to be 2 bolts that makes me thinks it mounts to something. anyone have any idea where this module should be module should be mounted inside the door.

 

[Haspin FJ]

If were talking about the door control module it mounts between the door panel and plastic lining in a recessed area in the plastic if I remember correctly. If not was just down in the bottom of the door where it could get wet that could be the whole problem.

Also for the corroded connector you can cut the power and use a 50/50 vinegar and salt mix to get rid of the corrosion, followed by baking soda in water to neutralize it. Google search of not familiar but it will make those blue connectors look new again.