E34 #68 Error Code

[siarach]

Hi Guys,
My 1995 (E34) 520i has got a lumpy Idle, stalls out, generally running rough, it has thrown up fault code 68? Where do i look??
Any advice gratefully accepted.
Regards
John M

[shogun]

I can only find something for the E46 M52TU, DME fault code 67/68 - VANOS end position regulation,
Complaint: Whenever a camshaft pulse generator (inlet or exhaust) is renewed, the engine will enter emergency running mode, i.e. the engine will run with reduced torque and output.
The following fault codes are stored in the DME fault memory:
Fault code ”67” VANOS end position regulation - fault on inlet camshaft, and/or Fault code ”68” VANOS end position regulation - fault on exhaust camshaft
https://www.newtis.info/tisv2/a/en/e46-320ci-cou/repair-manuals/12-engine-electrical-system/2a7u6UU

[siarach]

Thanks Shogun,
VANOS end position regulation? Is there a sensor for that?
Regards
John M

[shogun]

I do not know you engine at all, maybe first you check with your VIN in the ETK if that engine has VANOS and how it works http://bmwfans.info/

[Rustam]

Shouldn't Bentley's Repair Manual have code listings? What is the engine management system in this car? 1) Locate the computer in the electronics box on the right side under the bonnet, remove it and read the labels/stickers on it to determine engine management type. POST PICTURES to make it easier for members to help you. 2)Look for explanation of the codes in the same engine management for other available enginees (inline 6) If couldn't find a code listing explicitly given for your engine. 3)Google engine management type + engine type (M number + B number) + "enine management code listing" 4)If don't know engine type then research Wikipedia. This s hould be a good start...

[Rustam]

Also: have you checked the regular suspects? Vacuum leaks, ignition wires, plugs, intake leaks, fuel filter clogged, wirings on sensors, etc. etc. etc.? check all of these things, starting with a visual examination. the car doesnt care if you find the explanation of the code, but does need these things running in order.

[genphreak]

We're not aware of Error 68 thrown on E34.

It may not be well documented. However later e34 520i was made with M52B20 engine, same error codes as other chassis such as the popular E36 M52 (B20/B25/B28) so best to look there for clues, as @Shogun did.

Here are all the possibilities:

>96 Error code - Description

2A68 VT-Output-stage (bank2)

2868 VVT-system overload bank2)

2E68 Knocking sensor signal 1
2768 Phase generator positioning failure
2768 Camshaft sensor inlet: phase position
M4x: 4cyl Control valve, Injector 1
68 VANOS, faulty exhaust reference value
68 Fault code memory error

68 Exhaust camshaft VANOS, over-advanced or system performance

M52 is a rock-solid engine, with age and wear things like cam sensors, oxygen sensors and injectors should all be changed/checked good. Make sure FIRST your battery is capable of maintaining >12.0V with a load on it. Old batteries can cause voltage drops that generate errors- but usually airbag ones. Also can cause limp mode, no start, and many other strange things- to the point where the sane end up believing in ghosts.

Whilst running system voltage should be 13.7-14.0V.

[Rustam]

We're not aware of Error 68 thrown on E34.
.
Be careful, responding to him maybe a waste of efforts and time. Seems another unappreciative garbage case of posting and not caring to come back to see and acknowledge the help and time put into it, as well as provide followup findings. Garbage behaviour.

[genphreak]

Be careful, responding to him maybe a waste of efforts and time. Seems another unappreciative garbage case of posting and not caring to come back to see and acknowledge the help and time put into it, as well as provide followup findings. Garbage behaviour. Thanks Rustam, there is much time between the replies so no doubt John has gone elsewhere looking for some hints to his fix.

At least he came here and posted, and #68 got a mention, which could be helpful to someone, some day.