View Full Version : Would a bad CPS cause LIMP Mode?
nrowensby 05-13-2008, 11:42 AM My car appears to be in LIMP mode, but is only throwing a "Camshaft Position Sensor: Short or Open to Plus" code in VAG-Com... Would a bad CPS normally cause limp mode? I am awaiting the arrival of the "special order only" part from the VW/Audi Dealer, but I am worried it might be something more...
auditech79 05-13-2008, 11:45 AM No it won't cause limp mode, but it will probably run like ass which would make it seem like its in limp mode.
nrowensby 05-13-2008, 11:47 AM Definately running like ass, don't know if the car is truly in LIMP mode, because I am not getting a MIL... but it appears to not allow boost and accelleration is horrible.
auditech79 05-13-2008, 11:51 AM Well if the ECM doesn't know exactly when to fire the plugs its not gonna develop any boost.
Give the wiring a quick visual and make sure the connector to the sensor isn't messed up. If it looks ok replace the sensor. Un-less you did a timing belt recently?
nrowensby 05-13-2008, 11:52 AM No timing belt job done recently... I did a valve cover gasket, two days before the problem appeared.
auditech79 05-13-2008, 11:58 AM Well the cam sensor is right on the front of the cylinder head next to the valve cover gasket. You might have gotten a little oil on the sensor, im not sure if that would mess it up for certain, but i would take it off and clean it just to try it. Spray some brake cleaner on it.
nrowensby 05-13-2008, 12:04 PM Already took it off and cleaned it and no change... The new one should be here today and I will get it on this evening.
What are the chances that the car could've jumped time? Would that cause a MIL?
auditech79 05-13-2008, 12:08 PM Yep there is a possiblity, and thats actually a better chance than the sensor being bad. The last 3 people i helped with cam sensor fault codes happened to be a loose timing belt. So pop off the upper cover and see if there is any slack in the belt. The rule of thumb is you shouldn't be able to twist the belt 90*, pretty tight.
nrowensby 05-13-2008, 12:34 PM Well, if the sensor doesn't fix it, then I guess I will be doing a timing belt and suspension at the same time this weekend.
Wouldn't that cause a MIL though?
auditech79 05-13-2008, 12:39 PM If the timing belt is off yes it will trigger a cam allocation fault, or out of time.
nrowensby 05-13-2008, 10:04 PM New CPS is in... Still throwing code... :(
Camshaft Position Sensor (G40): Short or Open to Plus
-------- Intermittent
Checked it out in the eBahn(R) Repair and checked the wiring and the voltage with multimeter, everything checks out.
Checked tension on timing belt, there appears to be some slack, but wasn't able to quite twist it 90 degrees.
My only question is: Would it be throwing this code or the Camshaft correlation code?
auditech79 05-13-2008, 10:09 PM I would stop driving the car at this moment and take apart the front end, get the timing covers off and get a real good look at your hydraulic tensioner, if its leaking thats the cause of the extra slack in the belt and the cam fault code. What mileage are you at? How long has it been since you've done the timing belt?
nrowensby 05-13-2008, 10:12 PM The timing belt was said to be done by previous owner around 90k, I'm a little under 150... The car is not being driven at the time...
It's being prepped for surgery tomorrow when I get off... Going to pick up timing belt and tensioner tomorrow on lunch and ripping the front end off when I get off.
auditech79 05-13-2008, 10:14 PM Make sure to buy both the hydraulic tensioner and the eccentric roller tensioner, at that mileage both need to be changed.
nrowensby 05-13-2008, 10:19 PM Will do... you don't happen to have part numbers that I need to get from the VW store? Do ya? :D
nrowensby 05-16-2008, 12:33 PM Timing belt was changed... Car running 1000% better :D Also fixed a bad vaccuum line that I noticed while I was in there.
auditech79 05-16-2008, 01:06 PM Thats good, im gonna have to ADD a cam position sensor short to positive under timing belt failure as well, its wierd because that fault code doesn't make any sense. It means the sensor has a short going to the sensor. Oh well, as long as its fixed. [8D]
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