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No resistance in headlights fix

Posted: Fri Jan 12, 2018 10:24 pm
by Patzilic
Hi all,

I've recently upgraded to a custom built set of headlights with dual HID projectors and switchback angel eyes. Everything is on relays now (hi/low beam and parkers) so there is no resistance being detected and I don't want to damage the bcm

Is there a way to fix this with forscan or will I have to buy resistor and put them in? If I need resistors could someone point me in the right direction on what to buy.

Cheers for the help

Re: No resistance in headlights fix

Posted: Mon Jan 15, 2018 10:13 pm
by saeb
You will not harm the BCM, the FETS which even stop after a certain amount of counts are limited to overload protection eg. drawing too much current and or short circuits. Using relays will avoid this issue although you may experience fault codes in the BCM or dash lights indicating that the lights are not functioning.

I do not believe the front parkers are monitored. If high beam gives you errors after your chosen changes below then let me know and I will give you one extra change that was introduced sometime in the 2016 BCM firmware.

Front Indicators outage
726-27-01
enabled x1xx-xxxx-xxxx - default
Disabled x0xx-xxxx-xxxx

Low Beam Outage
726-27-02
enabled xxx1-xxxx-xxxx - default
Disabled xxx0-xxxx-xxxx

Rear Indicator outage
726-27-02
enabled xxxx-xxxx-x1xx - default
Disabled xxxx-xxxx-x0xx