Posted by Pete Mutlow on January 27, 2010, 7:00 pm
Year of Manufacture *: 2001 Engine Code or CC *: 2.0 Ltr (AZM) ( Optional ) Scanner Used: ACR4 G2 + Solus + ACT2
Evening All,
I would welcome your thoughts on this: Called to a garage to look at this car primarily to scope Camshaft Position Sensor. They had diagnosed a faulty Sensor following DTC PO342 (Camshaft Position Sensor - voltage low). This was replaced by a main dealer item and the code will not close down.
I verified the code and although will cancel with KOEO will appear immediately the engine is started. From cold, the engine does not sound "right" with what sounds like a minor mis-fire but sounds OK when hot. Emissions were perfect.
Pico-scoped the sensor and got a flat line from the signal wire. No voltage was present on multimeter but had good earth (to battery) and supply voltage was ok at 5.03v. I do not have specific information on this sensor and therefore could not verify resistances. Continuity at the 3 pin connector was good.
My theory is that either, they have another faulty sensor, possible cam-shaft end-float? or a dodgy reluctor at the back of the pulley. They think the cam-belt was changed about a year ago.
Your thoughts and/or resistance values would be welcome.
if it has a power and an earth does that not make it an active sensor and therefore a resistance check may well kill it? Regards markModern cars, Its all wizardry and witchcraft
Re: VW Passat - Fault Code PO342
Posted by Alan Kane on January 28, 2010, 8:33 am, in reply to "VW Passat - Fault Code PO342" Alan Kane - Administrator
I think that’s a hall sensor with 5v supply and 5v ref for signal. If so, you are missing the 5v signal ref. Check with it unplugged. Supply and ground are usually the outside pins and the middle one the signal.
I think a can of worms may be opened when you mention that a resistance check could kill the sensor. I have heard of this before and I prefer to measure the voltage of sensors because if that is correct, then the resistance is of no consequence. If the voltage is wrong - then I would want to check continuity etc. Also, why are all my Auto-data books showing resistance values and frustratingly little of voltages?
I understand what the voltages should be but by disconnecting the sensor does not prove the integrity of the system ie. camshaft end-float etc.
Anyway, spoke to the garage this morning and they will be checking the ideas I had in my first post. Customer does not want to spend too much money, so there may not be an out-come on this.
on January 27, 2010, 10:39 pm, in reply to "