How To: DRL Disarm aka LSM Position 0 Disable

This How-To describes what I will call the “DRL Disarm” (because “DRL Disable” has been used extensively to mean the VIDA software part #30679690) – making it safe to retrofit HIDs in P1 Volvos using the SKBOWE error harness. The “Dimmed Low Beam” DRL issue with HID conversions in P1 only occurs with the LSM in Position 0, as shown below, so this mod prevents the CEM from sending low-duty-cycle PWM to the HID ballasts during the day, when the LSM is in Position 0 (“off”), essentially turning Pos 0 into Pos II.

OE USA SWDisable SWDRL Disarm
Pos 0 (Day)Dimmed 9VOffPWM 13V
Pos 0 (Night)PWM 13VOffPWM 13V
Pos I (1)Off (parking)Off (parking)Off (parking)
Pos II (2)PWM 13VPWM 13VPWM 13V

Many advantages to this solution:

  1. It’s super easy!
  2. It’s free! No cost to flash software, or need to explain to dealer, or record with Volvo.
  3. It’s 100% reversible (also free) if you need to remove the HIDs later
  4. Just as safe as DRL disable for SKBOWE operation
  5. Function compared to stock remains unchanged (low beam still on in Pos0), in regions where DRLs are required, this keeps the functionality intact.

Only disadvantage compared to DRL disable is that you can’t be cool and turn off your lights (not that you could before!)

Remember, you don’t *have* to do this – the same thing is accomplished by leaving the LSM in PosII all of the time. But it prevents any potential issues if you (or other driver, or shop) forgets to do so.

How does it work?

Inside of the LSM, there are two small switches, one for Position 0, and one for Position 1. There is no switch for Position 2 (which is detected when neither 0 or 1 is closed). The CEM thinks that the LSM is in Pos0 when Pin 6 of the LSM (black/green wire, and B:2 of the CEM) is connected to ground, so by disconnecting this wire as shown in the diagram below, the CEM will never think the LSM is in Position 0, and the daytime dimmed DRL condition can not occur!


The LSM in position 0
For reference, this is the LSM in position “0”, when DRLs are activated on cars with the CEM program installed.
LSM diagram with pin 6 hack
By removing LSM pin 6 (shown by red X above) the CEM will never think the LSM is in Position 0.

You could cut this wire and be done in 10 seconds, but this can be done reversibly in about 5 minutes. Either way, it’s simple, effective, and free!

How To: Reversible DRL Disarm

Step 1: Gather Tools / Materials. Easy!

Gather parts: Small flat screwdriver, spudger, large paperclip, and electrical tape
  • Large paperclip, or other similar size stiff wire. You could probably use a small/normal size paper clip, but the large ones are exactly the right size to release the pins.
  • (Optional) Small flat screwdriver to disengage connector lock
  • (Optional) Nylon spudger to remove LSM
  • (Optional) Electrical Tape will to secure the removed pin.


Step 2: Remove the LSM. This is easiest using a non-marring spudger, but if you don’t have one: Grab the door-facing panel inside the jamb by the air grate and pull out, then push the LSM out from the backside. Once it’s free, disconnect the electrical connector.

Removing the LSM
Remove LSM using spudger. Alternately, pull out the cover to the side of it and push it out from the back.
LSM removed
Once free, remove the LSM and disconnect the electrical connector.

Step 3: Identify Pin 6. It’s the black/green wire as shown below.

Back of LSM with Pin6 circled
Back of the LSM, showing location of Pin 6
LSM connector showing Pin6
Back of LSM connector showing Pin 6. It’s the black/green wire in MY2005

Step 4: Unlock Pin Retainer Clip. Careful as to not break it off, slowly pry up the pin retainer clip. It swings up and out. I find a small flat-head screwdriver works well for this.

Unlocking the retaining clip
To unlock the retainer clip, insert screwdriver as shown and carefully pry up.
Retainer clip disengaged
Retainer clip disengaged. The little plastic tabs are a backup mechanism hold the pins in place.

Step 5: Remove Pin 6 from the connector. This is super easy once you get the hang of it, but if it’s your first time, it can be a little tricky. Unfold the paperclip and insert it into the upper hole above pin 6. It will slide in easy at first, then there will be some resistance – keep pushing until it gets firm. Then, keep slight inward pressure with one hand, while pulling the wire out with the other. If lined up right, the wire+pin should come right out.

Bent paperclip
Bend the paperclip straight to make a pin remover. Large paperclips work best for the Green Volvo Connectors
Shows where to insert paperclip
Insert paperclip into the remover slot for Pin 6 (click for bigger).

If you can not easily pull the wire out, remove and re-insert the paperclip, maybe wiggle a little bit. The pin should come out with very little force at all. If you pull too hard, it will break the primary retainer plastic and you won’t be able to re-install the pin later.

Step 6: Remove and Secure Pin 6. Once the pin is out (left) replace the retainer clip by pressing it back down gently into the connector. Use some tape (right) to hold the loose pin out of the way.

Pin6 removed.
Pin 6 halfway out of the connector. After pulling it all the way out, press the retainer clip back down gently into the connector.
Pin 6 taped back
Tape the loose wire to the harness so it looks like nothing ever happened!

Step 7: Installation is reverse of removal… It’s now safe to run HIDs with SKBOWE in any LSM position! The low-beams will turn on in Position 0 and Position II.

LSM installed
Reinstall LSM, ensure that the lights come on in 0 and II.