Cam sensor fault code p0343

[jetbox]

Hi,

I have the following fault code on my 996 c4 my2000

P0343
112 Camshaft Position Sensor 1 "" Above Limit

I removed the sensor and checked out using the diagnostic info and found that I read battery voltage on pin III/20 (pin 2 on sensor plug). The troubleshooting says short on the wire and points to wire damage but even disconnecting the wire from the dme and the dme pin reads battery voltage all the time.

Now I am stuck, looks like a DME internal fault or could other wiring external to the dme cause this reading?

Any help appreciated

Could the troubleshooting procedure be wrong as i thought dme's were very very reliable??

The car symptoms are, starts and drives ok but slow to rev over 3k ish. no CEL

 

[Richard_Hamilton]

On my diagnostic sheet there is only one test for P0343 Above limit, which says: "Check signal wire from DME control module, pin III/20, to CMP sensor for short circuit to B+."

If I am reading the diagnostic sheet correctly, and you are getting 12v+ to pin 2 on the CMP plug when the plug on the DME is disconnected, they you have a wiring fault. A short to B+ (ie 12v+).

 

[jetbox]

Hi,

Yes I have 12v on the pin two wire. I have disconnected just the pin 2 wire from the dme (just this wire all connectors plugged in ) and then I can still read 12v FROM the dme which means the voltage is coming out from the dme??? So I am reading 12v from the dme side not the engine loom side , hope this makes sense.

Any suggestions?


thanks

 

[Richard_Hamilton]

The connections on the DME are:

Plug 3, Pin 7 = 5V+, to CMP plug pin 3
Plug 3, Pin 20 = Signal, from CMP pin 2
Plug 3, Pin 17 = Ground, to CMP pin 1

If you disconnect DME Plug 3 pin 20, and are still getting 12v+ on CMP pin 2, then there is a short in the loom to a 12v supply.

If you are getting 12v+ from the DME Plug 3 pin 20, then it sounds like it might be a faulty DME.

 

[jetbox]

Hi,

The daignostic manual i have says its plug 3 pin 20? I have continuity checked from this pin to cms pin 2 and it checks out.

Dme pin 20 has the battery voltage.

Do you have any info on the internals of the dme?

Have you had experience of the ecu repair places in the uk? Is it worth sending to them for testing and repair?


Many thanks for your help... This ones got me really stumped!

 

[Richard_Hamilton]

Sorry - you are correct, it is pin 20. (More haste, less speed required!). I will correct my pervious post.

I haven't and experience of ecu repair places, I'm afraid, but it is woth a shot, as a new one is £1455.

If you try to get a second hand unit, it will only be any good if it comes with the DME Programming Code. The units can be programmed for another car, but you need this code, and the Immobiliser Code from your own car.