P0343 Code

[uabchris]

Hi all,

I just got a P0343 Code (Canshaft position sensor 1) on my 2000 Boxster 2.7. Any ideas? Car seems to run fine. 155K, but had new engine at 95K.

Thanks in advance!

Chris

[Loren]

P0343 Camshaft Position Sensor 1 – Above Limit

Potential causes:

– Short circuit to B+

Check the connector/wiring.

Check signal wire from DME control module, pin III/20, to CMP sensor for short circuit to B+.

1. Connect special tool 9637 to wiring harness (DME control module connector).

2. Remove connector of CMP sensor.

3. Connect voltmeter to special tool 9637, pin III/20, and ground.

Switch on the ignition.

Display: 0 V

If battery voltage is displayed, check wiring harness for chafing and pinching damage.

[uabchris]

Thanks for the quick reply! One more question, where can I get the special tool 9637, and can this test be accomplished without it? also, I chrcked Pelican Parts for the sensors and did not see available. Can they be purchased online or is it a dealer item?

Thanks again :)

Chris

[Loren]

It is like a breakout box for the DME. I suggest you borrow one from a shop - Porsche tools tend to be very pricey.

[uabchris]

Thanks for the great info, Loren! I will start troubleshooting tomorrow. Just for a sanity check, I am looking for the Cam Position Sensor 1(P0343, meaning bank 1-3) on passenger side rear...right? Am I correct that it is the sensor in the valve cover(next to vario cam script) in plain view with RR tire removed, and the other(bank 4-6) on the opposite front LH side? 2 -10mm bolts should do the job...

Thanks again! :renntech:

[Bernd-993]

after repairing the VarioCam on bank 1 (engine M96-04) and replacing the camshaft position sensor I still receive P0343. I checked the wiring and voltages. When I draw the connector and ignition is on I receive 5V / 12V / 0V on the sensor connector. This is the situation on bank 1 and bank 2. It looks like the 12V=B+ comes from the DME at iii/20 and iii/19 vs ground. This voltage seems to feed a 20mA circuit inside the camshaft position sensors.

When I look at the scope picture provided in the Porsche diagnosis manual the signal level with running engine is jumping between ~13V and zero. Therefore, I don't understand the testing procedure for P0343,

Check signal wire from DME control module, pin III/20, to CMP sensor for short circuit to B+.

1. Connect special tool 9637 to wiring harness (DME control module connector).

2. Remove connector of CMP sensor.

3. Connect voltmeter to special tool 9637, pin III/20, and ground.

Switch on the ignition.

Display: 0 V

If battery voltage is displayed, check wiring harness for chafing and pinching damage.

The voltage should read 0V but the DME in my car provides 12V for both pins III/20 and III/19! I measure directly at the cable connected to the DME and don't have a breakout box. P0343 indicates that only bank 1 sensor circuit is above limit.

What is wrong here? I need to fix the error since I my 996C4(2001) will fail the German TUV.

[logray]

For ME7.2 on a 2001 car, to me it looks like pins 19 and 20 are the 12 volt signal to the hall sensors, pin 2 respectively. And pin 1 is ground.

If you are reading 12v+ with ignition on from pins 19 and 20 while grounded, I think your DME might be faulty, or at least perhaps you aren't testing the correct pins. My copy of the wiring diagram is poor, but it looks like 19 & 20 are on DME connector 3 (III).

To me it looks like the 5 volt signal comes from J185 on wire RE/VI and is wired in series to both hall sensors on pin 3 (although yours is ROW car, so might only have one hall sender).

"When I look at the scope picture provided in the Porsche diagnosis manual the signal level with running engine is jumping between ~13V and zero. Therefore, I don't understand the testing procedure for P0343,"

I am guessing this is because the hall sender measures when camshafts are rotating each time the reference mark on the cam passes over the sensor you see the voltage spikes, then goes back to 0 until the next revolution. But with the camshafts not moving, maybe it is supposed to read 0 volts? Not sure though, could be the other way around. Maybe while you are measuring your engine happened to stop at a point where one of the hall sensors is over the reference mark on the camshaft? That would be pretty lucky though.

Did you try replacing the cam sensor?

It might also be an error in the troulbeshooting documentation, I found another documentation error a few days ago (I think, still researching)

Did you test for continuity between the CMP connector and the DME? And did you also check the resistance of those wires? If there is excess resistance or no continuity, then maybe the problem is with the wiring (since in your testing procedures you measure the voltage on the wires, and also on the DME itself, but I don't see a test for the wire path, although the voltage test does fulfill that somewhat).

Do you have a Durametric or PST2 to read the camshaft deviation?

Just throwing out ideas.

Edited February 28, 2012 by logray

[Bernd-993]

Hello 'Contributor', thanks for the quick reply!

Yes, the car is a US model reimport from New Jersey to Bremerhaven in 2007 and was running good in the last couple of years. The only annoying thing was the CEL for different reasons, VarioCam, Camshaft sensor up to a bad sealing tank cap.

The camshaft sensor was replaced a couple of weeks ago bcause of P0341 error code. Now, a P0343 is still active. I tested the wiring of both sensors, 5V ok, ground ok, the resistance of the signal cable is ~0Ohm. When I pull the connector from the Hall sensor I measure B+ at pin 2 that is connected with pin III/20 of the DME while ignition is on. The same situation holds for bank 2 sensor that is connected to III/19, shows also 12V. It is very unlikely that there is a shortage to B+ but I plan further tests on the weekend.

It would be of interest whether the DME unit is faulty?

I used a notebook based Porsche tester from a workshop nearby that seems reliable. I cannot read the camshaft deviation since the sensor signal is not plausible. Wrong timing of bank 1 may be a possible issue to receive an implausible camshaft sensor signal. When the VarioCam actuator was repaired the cam stting was carefully set with a Porsche special tool.