mk6 transit bus 2.0 tdci. cam and knock sensor issues

[JRAMSDEN84]

hi, im new to transits, i recently bought a mk6 bus because i need the extra seats, it seems to have a few issues so here they are....

2004 mk6 transit bus 2.0 tdci (gauge cluster with the rev counter)

fault codes

cam sensor, knock sensor and air con error (i think it said compressor)

other issues

sometimes it will start and immediate die

when under full power, the power feels like it comes and goes

doesnt seem to have any power after 3k

i have replaced the cam sensor but still randomly comes up with the fault

i have limited knowledge with diesels any help would be great.

thanks

[wojciech]

fault codes:

cam sensor, knock sensor and air con error

other issues

i have replaced the cam sensor but still randomly comes up with the fault

sometimes it will start and immediate die

Cam sensor (CMP sensor) is necessary for IDM/PCM module for injectors control in right order and for identify of first cylinder. If IDM/PCM doesn't see correct impuls from CMP sensor, engine cant't start (injection dose dose =0).
So - if you replaced CMP sensor, but still is his error - maybe his electric wire is broken. It can be electrical short to ground - one time it works, one time not...
CMP sensor error is atypical in Duratorq tdci - it isn't recorded in PCM memory, it is visible only during this time, when CMP sensor is broken. But CMP sensor it is Hall sensor (semiconductor structure), it needs for work power (+5V) and many times his condition is unstable. In your case check wire and voltage in plug.

Knock sensor and AC sensor have nothing to do with engine start. But you should replace knock sensor.

For no power after 3k rpm - check all vacu pipes for turbo actuator, check EGR is it blinded, if not - do it (look for my posts about it - two minutes of work), check vacu pipe between main vacu pipe and vacu container (under windscreen in engine compartment).
Check how works turbo actuator on idle- during idle disconnect and connect vacu pipe into actuator. Tie shuold answer immediately between end positions.
Check all rubber inlet pipes between turbo and IC, IC and EGR and between EGR and engine. Do it by hand on highest speed - are needed two people.

[wojciech]

And you can do... hundreed another things...

[JRAMSDEN84]

i have disconnected the vac line to the egr . this seems to have solved the power issue...

as for the cam and knock sensor errors i have found if you touch the loom in the engine bay (two large connectors) directly below the positive battery terminal on the chassis rail it brings up the errors and puts the van into limp mode.

im sure its a damaged wire or corroded connection . do these sensor share the same positive or earth feed?

[wojciech]

i have found if you touch the loom in the engine bay (two large connectors) directly below the positive battery?

Which one
Knock sensor and cam sensor are powered from the same fuse - "engine management". But how they are connected to PCM - I don't know. Try find wire damage and insulate it.

[JRAMSDEN84]

well ive disconnected those two connectors and re connected them , then ive wiggled the wires and no faults are coming up.

maybe it was a poor connection.


as for the air con.. the van has been regassed but it still wont work. ive found a missing relay under the bonnet so ive replaced that but still no joy.

i the shorted the sensor on to of the evap canister and this started the compressor but no condenser fan.

does this van have a separate control module for the air con?

[wojciech]

It can be your condenser fans are broken and refrigerant fluid has too high temperature (sensor in drier-filter).
Check fans resistors and check funs.
If you bridge contacts nr 3 and 5 in relay R12 socket - both funs should start work with half power. It is test for resistors and funs. Check also fuse 105 (40A) .

[JRAMSDEN84]

just bridged it and the fan will not run. also fuse is good

[JRAMSDEN84]

there is power to the relay and the relay seems to operate. i can see both the fans plug into a black box located on the fan shroud is this the resistor box?

[wojciech]

You have problem, big or very big.
Propably fun resistors are broken or are broken funs engines, or both.
In my case it was broken resistors and one fun engine.
Genuine parts are available only all together - two funs, resistors and housing. It cost cost an arm and a leg. In Poland 700 GBP. There is no resistors as separate spare parts.
So I bought all in housing from Polish ebay for 60 GBP - I was lucky.

Now you should take out both funs and resistors with housing and check funs without resistors (full speed). If they run, you are lucky little bit, your problem are only resistors. Maybe from other car or... I don't know...
It is possible to check funs work without resistor using their plug under van, but it's clear that resistors are broken and all housing should be disassembled...

If funs also will not work without resistors or only one fun will work - best solution is to buy all together, nice looking, from ebay or somewhere else.

[wojciech]

there is power to the relay and the relay seems to operate. i can see both the fans plug into a black box located on the fan shroud is this the resistor box?

Red arrow - resistors.
In plug are pins you can connect funs via resistor (half speed, relay R12 ) or directly to +12V (full speed, relay AR7).

[JRAMSDEN84]

i have just taken the fans off the van . the resistor looks terrible so i assume this is the cause .

i will test this with a multimeter and see if it is bad.

i will test the fans tomorrow morning on full power to check they are ok

[JRAMSDEN84]

does anyone know the resistor values . i might be able to replace them

[wojciech]

does anyone know the resistor values . i might be able to replace them

No genuine resistors on the market... In other cars funs have different power, so resistors are also different.
Try read viewtopic.php?f=5&t=163332&start=15

[JRAMSDEN84]

http://www.generator-loadbank.com/photo/pl17304192-200w_high_power_glazed_ceramic_tube_wire_wound_regenerative_braking_resistors.jpg