Thread: DSC towing problem

Do the van's brakes activate when you switch on parkers or headlights? If so the the car's wiring harness behind the left tail-light hasn't been modified for Australian trailer/van wiring.

Originally Posted by Pedro_The_Swift

Does a D3 cutout from overboost?

Certainly does. My 05 D3 shows overboost and goes into limp mode when towing if im not careful. Happens most often when changing down gears under load - i now manually swap cogs when towing and back off a bit when changing gears and it minimises the limp home mode popping up at an inconvinent time. Must be getting a tired turbo so will need to replace it one day (actuator moves nice and smoothly and is not jamming or sticking).

Shane,

Have you checked the o ring seal between the intake plenum and throttle body? This I've found is a very common cause of restricted performance issues.

Originally Posted by BobD

Yes, I realize that and have now changed my post. Sorry about the misleading post. See the later one today which is relevant to your problems, as is the one you have quoted, apart from the fact that D3's actually do need the module to stop the pulsing indicator lights and get the car to recognize the trailer, unlike a D4.

What is your answer to my later post today re the correct wiring of the brake controller? Are your trailer brakes working correctly when you put your foot on the brake in the D3? As I said, none of the problems you have listed are because the trailer has LED lights, apart from the lack of the trailer symbol flashing on the dash.

hi bob the brakes on the van work ok the only problem is with the lights turn on the headlights the blinkers pulsate hit the footbrake and the blinkers pulsate have checked the wiring twice fitted a module..question if i replace the two taillights with normal lights will this fix the problem taking into consideration the clearance lamps are all led but work ok no flashing pamx

Are you sure that you got a D3 version of the module, not a D4 version? Without knowing what's inside their D3 version of the module, a D3 module needs to have relays for the blinker circuits because relays won't be switched on by the short test pulses, only by the proper blinker switching. D4s don't continuously test the blinkers so a D4 module does not need relays. If your module is a D4 version then it is not suitable for your D3.

The relays don't have to be mechanical, they can be electronic providing the electronics in the module ensure that the pulse is not just a short test pulse before switching on the electronic relay.

Originally Posted by Eric SDV6SE

Shane,

Have you checked the o ring seal between the intake plenum and throttle body? This I've found is a very common cause of restricted performance issues.

No I havent, will definatly be worth a look. End of the day I havent gotten to worried about it yet as it doesnt fault when Im not towing

Originally Posted by shanegtr

No I havent, will definatly be worth a look. End of the day I havent gotten to worried about it yet as it doesnt fault when Im not towing

Smoke test is your friend. Sounds like a leak to me. My split throttle body only ever gave me grief when towing too, until it finally gave out

Trailer assist is mechanical and doesn't need the wiring of the trailer to connected, so you can rule that out if you have a D4, also to stop the issue of LEDs on the trailer in the D4, just turn your lights on and everything will work normally except the trailer symbol on the dash.

The issue will be the trailer not set up properly or the suspension on the car is shagged.

Probably not any help to the OP but just a heads up for those with TSA.

Trailer Stability Assist
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