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This past Sunday I'm driving my 03' 350 track package(stock wheels, brembo brakes, suspension is just koni struts, no engine mods), I'm getting on the throttle a bit and it cuts back like traction control came on with slip. It happened again the next time I opened it up but it cut then went back to WOT. I thought it was funny so I shut the car off and tried WOT again, this time I had nothing past 50% throttle. Looked up stuff online and here and other guys say they've had problems with TPS saying it won't throw codes or a CEL when it goes bad. Also when it goes bad the cruise control won't set, I also have that.
So sounds like TPS... Well I drop it at the dealer monday morning cause I'm working 14hour days this week and stress that I need the car back for Friday. They didn't put it on a lift till last night and now call to say they are 4 hours into a diagnosis and still can't find the problem.
Do I go pull the car outta there and start swapping on new parts myself or let them keep racking up a bill? I'm supposed to be racing it Saturday, stock class track day and then doing first AutoX of the season Sunday.
More info. Yes, tire size is not stock. I read up on the traction control not liking certain staggered size tires and front to rear circumference needs to be 1-3% smaller and my current setup sits at 1.8%. And to double check I put on stock size tires/wheels and still experienced only half throttle.
You didn't mention whether the dealer found any trouble codes when the scanned your ECM? That should be the starting point. And I wouldn't say you're getting boned by anybody- after all, you brought the car into them with a problem and said 'fix it'. Also, not sure what you mean by TPS (tire pressure sensor)?
Well good guesses guys. I actually did check tail lights, no codes and no CEL
The dealer found that the vehicle dynamic control module has gone bad. They were listed as $1050 from nissan however they are no longer stocked and no dealer in the country has one.
Well i learned that the module i need only came on 03' and 04' models with the dynamic traction control. I ended up finding a wrecker who had the part for $150. It's a small aluminum box that bolts to the bottom of the steering column near your feet. One wire (pink w/blue stripe) was sending a random 5 volts to the ecu making the car think the brake lights are on reducing throttle.*
So I took the car home from the dealer, they pulled the pin outta the connector for that pink/blue wire causing the problem. It just means all the traction lights and abs is off till I fix everything myself.
Well here is the new VDC module the dealer says went bad. I replaced it, then started looking for the pin they pulled out of the connector and found this...
Well after flipping out because they cut the wiring harness open I took the car for a drive and I'm back to the original problem!!! I'm better off opening that wire back up and doing my track day tomorrow with no traction control or abs
Well I fixed the car myself and you guys won't believe what it was. The dealer diagnosed the problem as a brake input fault in the VDC module, it was sending 5 volts to the ecu on that pink wire they cut telling it to cut throttle. And they were correct... However the module was working 100% and that's where they were wrong cause there's a reason for the module to have the bad signal.
Last Saturday the new led taillights I ordered as a quick replacement for my leaky, water filled stock bulb ones came in and I put them on. Sunday afternoon I noticed the problem started. Well as it turns out the LED bulbs complete the circut even when not lit making the computer think that the brake lights were on and purposely cut throttle.
Cost of eBay LED tail lights $125, 4 hour diagnosis from dealer $436, the new VDC module from a JY $150. For a total of $711 all because of a cheap set of china lights that prob need an extra resistor so the circut matches the stock bulb resistance. And yes, I was amazed when I swapped taillights 4 times and got the bad results each time with LEDs and good with stock bulbs.
Well I fixed the car myself and you guys won't believe what it was. The dealer diagnosed the problem as a brake input fault in the VDC module, it was sending 5 volts to the ecu on that pink wire they cut telling it to cut throttle. And they were correct... However the module was working 100% and that's where they were wrong cause there's a reason for the module to have the bad signal.
Last Saturday the new led taillights I ordered as a quick replacement for my leaky, water filled stock bulb ones came in and I put them on. Sunday afternoon I noticed the problem started. Well as it turns out the LED bulbs complete the circut even when not lit making the computer think that the brake lights were on and purposely cut throttle.
Cost of eBay LED tail lights $125, 4 hour diagnosis from dealer $436, the new VDC module from a JY $150. For a total of $711 all because of a cheap set of china lights that prob need an extra resistor so the circut matches the stock bulb resistance. And yes, I was amazed when I swapped taillights 4 times and got the bad results each time with LEDs and good with stock bulbs.
Wow, glad you got it sorted after the time and $$$. Makes you wonder tho why engineers chose the tails for the signal rather than the brake pedal switch itself.
04-09-2015, 07:52 AM
Boned by dealer?
