P2686 fault code what does it mean ?

[KennyW]

Long story re above but what does it mean ?

From Diagbox

Camshaft sensor p2686 - supply of sensors 5volts no 3 wire.

I have checked the continuity of wiring from sensor plug to ECU all okay.

Looking for info

Kenny

[Huskyxantia]

There a magnet aren't they ? Maybe the pulses are irregular dirty sensor ?

[GiveMeABreak]

Details Kenny:

Fault Code:	P2686
Description of Fault:	Supply of sensors 5V no. 3 (Camshaft, engine speed, and fuel high pressure common injection rail pressure): Excess voltage seen by the regulator. Monitoring of the common supply of the sensors, voltage higher than 5,5 V for 100 ms (Supply: Aircon pressure, EGR exchanger by-pass position sensor, particle filter differential pressure sensor; Clutch sensor). At least one of the following conditions must be fulfilled Ignition on With the engine running
Conditions for Fault to clear:	Driving with the engine hot for 5 minutes
Downgrade Modes whilst Fault is active:	Deactivation of the traction control (Traction control) Performance of ESP settings impossible Request for Delayed Engine Stop Deactivation of the pilot and post-injection injections Deactivation of the strategy for monitoring the current of the fuel flow regulation valve Deactivation of the after-sales test for detection of leaks on the diesel fuel high pressure circuit Fuel flow regulation valve fully opened Deactivation of the kick-down for automatic gearboxes Deactivation of the injector resetting strategy Limitation of performance
Symptoms:	Starting problem Engine hesitating, cutting out Lack of power
Suspect Areas:	Supply of sensors 5V no. 3: Voltage outside the tolerance Engine speed sensor Fuel high pressure common injection rail pressure sensor Camshaft sensor Electrical harnesses

Injection Diagram for reference:



A couple of things worth checking:

1313: engine speed sensor /
1115: cylinder / reference sensor /

These share a common 5v supply (wires: 13C1B on Pin 3: supply +5V CM VCC2 on 1313 and 13C1A on pin 1: supply +5V CM VCC2 on 1115) and common earths too.

Whether you have an earth issue or a dodgy wiring harness it's hard to say if either.

[KennyW]

Thanks for the replies,

After having a think about the problem, I decided to recheck my wiring I did and bingo found problem I managed to wire up the Crankshaft sensor wrong.

Tomorrow will check the continuity but did that the first time and it was okay ! No breaks in the wiring, since I am checking them in a slightly different order, hopefully everything is okay.

Marc, as you said above dodgy wiring!!!!!!!!!!!!!!!!!

Kenny

[GiveMeABreak]

Good one Kenny

[KennyW]

Well the good news almost all fault codes have gone except for the following

P0336 and P0017
which are as follows

Fault Code: P0336
Description of Fault: Engine speed sensor: Signal absent when starting. Engine speed sensor absent detected for 2 s when starting
Conditions for Fault to clear: 10 successive starts
Downgrade Modes whilst Fault is active:
Symptoms: Starting problem, Jerking/stalling
Suspect Areas: Engine speed sensor, Connectors, The electrical harness, Engine speed sensor target

Fault Code: P0017
Description of Fault: Starting monitoring: Synchronisation time too long. Synchronisation time of more than 2 s between the camshaft sensor and the engine speed sensor.
Conditions for Fault to clear: 10 successive starts.
Downgrade Modes whilst Fault is active:
Symptoms: Starting problem
Suspect Areas: Camshaft sensor, Camshaft pulley, Engine speed sensor target, Engine speed sensor, Timing Belt, Electrical harnesses, Connectors

which are related.

I was going to check the continuity of the wiring today but rain stopped play.

Likewise, I am going to recheck the work carried out as I fitted a new engine sensor target and replaced timing belt as water pump was leaking slightly.

All of these are mentioned as possible suspect areas.

How can I check the engine speed sensor target ? I will check timing belt is in alignment. Can you check the crankshaft sensor ?

Kenny

[Huskyxantia]

Ohms resistance test youtube has videos of how to and what the ratings should be.

[KennyW]

Thanks Husky

[wheeler]

How can I check the engine speed sensor target ? I will check timing belt is in alignment. Can you check the crankshaft sensor ?

Apart from checking for correct fitting and for physical damage the only way to properly check the crank sensor & its target is with a scope. You can check its power supply & earth but the output really needs a scope to check it correctly.
The engine speed sensor is hall effect on this engine so ohms check is no good. Even on an old inductive style engine speed sensor a resistance check is not that accurate unless it's just went completely open circuit.

[KennyW]

Thanks Wheeler for the reply,
I watched several You Tube videos and that was the conclusion I came to.

But good news, I checked Crankshaft sensor wiring for continuity and discovered the following

No 1 no continuity
No 2 no Continuity
No 3 Continuity

Checked Camshaft sensor wiring for continuity all 3 are fine.

So the problem is the wiring possibly at my splices.

Will check there and update thread.

Kenny

[Huskyxantia]

How did you spice the joints ?
Reason for asking is I've spiced wire joints and found the solder for some reason didn't conduct current properly or the quick shrink type connectors didn't work.

[KennyW]

Husky previously I have twisted the wires together and soldered thereafter covered with heat shrink.

This time I used crushed bullet connectors which I think haven't worked.

Won't be able to check until weekend at the earliest.

Kenny

[myglaren]

Have you tried WAGO connectors?
Very quick and easy, also easy to remove.

They come in many and varied types.

https://www.wago.com/global/installatio ... p/221-2401

Plenty of information on YouTube about them. There are similar ones from Ideal.
Screwfix and Toolstation carry them, I bought mine from eBay.

A lot less hassle than grovelling about in the footwell with soldering irons or crimps.

[Huskyxantia]

I've ditched the bullet type last year, i twist bear copper to coper then solder & heat shrink , i think your have better results this weekend doing it the old fashioned way , stick with what works .

[KennyW]

I agree plus the joins are smaller and fit neatly whereas the bullet connectors are large bulky items which make the wiring look untidy.

That's my opinion anyway.

Kenny

PS Thanks Myglaren re the joiners