P38 2.5 DSE Automatic Gearbox

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damosmokie said:
Hi all I got it running yesterday & I now have a few issues. My rev counter is not working I have an orange light on the dash which looks like a spray jet and it is revving a little high. Any help would be appreciated.
Click to expand...
Diagnostics needed, could be the needle lift sensor, check the connection, check the crank sensor adjustment too.
 
Right I've checked absolutely everything. I've double checked the cps and the gap between the drive plate & it's spot on. I have also had it on a snap on diagnostics and it says the rpm sensor is at fault. Where is it?
 
damosmokie said:
Right I've checked absolutely everything. I've double checked the cps and the gap between the drive plate & it's spot on. I have also had it on a snap on diagnostics and it says the rpm sensor is at fault. Where is it?
Click to expand...

The cps is the rpm sensor :)

Must be a faulty one, that's second hand for you .
 
Last edited:
Grit Valve said:
The cps is the rpm sensor :)

Must be a faulty one, that's second hand for you .
Click to expand...

From RAVE:- Engine Speed Sensor = Crank Sensor.:)

[FONT=Arial, sans-serif]Sensors[/FONT]
[FONT=Arial, sans-serif]Engine Speed Sensor (X255)[/FONT]
[FONT=Arial, sans-serif]The engine speed signal is crucial to the system, as[/FONT]
[FONT=Arial, sans-serif]the information from the sensor is used in virtually all[/FONT]
[FONT=Arial, sans-serif]of the strategies within the ‘DDE’ (Digital Diesel[/FONT]
[FONT=Arial, sans-serif]Electronics) and its Engine Control Module (ECM)[/FONT]
[FONT=Arial, sans-serif](Z132). Through this sensor, the ECM (Z132) knows[/FONT]
[FONT=Arial, sans-serif]if the engine is turning, how fast it is turning and[/FONT]
[FONT=Arial, sans-serif]approximately where the engine is in its cycle. The[/FONT]
[FONT=Arial, sans-serif]sensor is of the ‘Hall effect’ type, which sends out a[/FONT]
[FONT=Arial, sans-serif]pulse to the ECM (Z132) every time a ‘tooth’ is[/FONT]
[FONT=Arial, sans-serif]sensed on the flywheel (the flywheel has six ‘teeth’).[/FONT]
[FONT=Arial, sans-serif]If the sensor fails, then the warning lamp is activated[/FONT]
[FONT=Arial, sans-serif]and the ECM (Z132) enters a ‘limp home’ mode[/FONT]
 
Is there a way that I can test the sensor? As a new one is nearly a £100 so I've been told. The cps reads from the 6 small pins on the back of the drive plate doesn't it? Would this cause the orange spray light to come on the dash & my rev counter to stop working?
 
As far as I'm aware the engine will go in limp mode if cps fails from a running engine as it has the needle lift sensor as a guide .
Once engine is switched off you will not get a restart with a failed cps sensor .
 
damosmokie said:
Is there a way that I can test the sensor? As a new one is nearly a £100 so I've been told. The cps reads from the 6 small pins on the back of the drive plate doesn't it? Would this cause the orange spray light to come on the dash & my rev counter to stop working?
Click to expand...
Read my last post, duff sensor lights the fault (MIL) light. Not sure where the rev counter is driven from.
The sensor can be checked on diagnostics or with an oscilloscope.
 
Grit Valve said:
As far as I'm aware the engine will go in limp mode if cps fails from a running engine as it has the needle lift sensor as a guide .
Once engine is switched off you will not get a restart with a failed cps sensor .
Click to expand...

Hi thanks for your info. I can start the range up everytime. It just ticks over at about 3000 revs by the sound of it.
 
On your old cps there was a spacer did you replace the spacer on to the second hand one ?
Sounds like its working but only Partially picking up signal its defo that if revs counter has stopped there is a fault somewhere with it .
Ps you might want to check you still have the 6 tabs remaining on the flywheel vai the inspection hole .
 
Last edited:
Grit Valve said:
On your old cps there was a spacer did you replace the spacer on to the second hand one ?
Sounds like its working but only Partially picking up signal its defo that if revs counter has stopped there is a fault somewhere with it .
Ps you might want to check you still have the 6 tabs remaining on the flywheel vai the inspection hole .
Click to expand...

When you say spacer do you mean the bracket that secure's it to the block?
 
Grit Valve said:
I'm sure there is a spacer that is like a shim and keeps it the correct distance .
Click to expand...
Is it not impossible to set up the CPS without a special tool if the adjustment has been disturbed? Normally the CPS can be replaced without disturbing the adjustment I believe, but if the mount has been removed it's a big problem.
 
No there wasn't a spacer like you describe I got a second hand one from Emmotts and they just said to swap the bracket over. They didn't mention a spacer. Have you got any images of this spacer.

The cps can be inserted all the way in till it touches the drive plate so there isn't any shim or spacer.
 
Last edited:
Datatek said:
Is it not impossible to set up the CPS without a special tool if the adjustment has been disturbed? Normally the CPS can be replaced without disturbing the adjustment I believe, but if the mount has been removed it's a big problem.
Click to expand...
Thanks new there was an ajustment somewhere did you move the mount op?
If so .....
 
Read below, if the mounting bracket has been removed you are in the mire, you need a special tool to re-position it. There are no spacers or shims.

BMW DIESEL
3 REPAIR
CRANKSHAFT POSITION SENSOR (CKP SENSOR)
Service repair no - 18.30.12
Remove
1. Disconnect battery negative lead.
2. Remove cooling fan cowl. See COOLING
SYSTEM, Repair.
NOTE: Cowl removed to give access to
crankshaft pulley for manual cranking of
engine.
3. Disconnect CKP sensor multiplug.
4. Remove bolt securing CKP sensor to bracket.
Remove CKP sensor.
CKP Sensor Bracket - Adjust
CAUTION: CKP Sensor bracket must be
correctly positioned. CKP sensor damage
or failure will result from mis-aligned
bracket.
5. Rotate crankshaft until flywheel TDC pole is
central to CKP sensor aperture.
NOTE: Use mirror and lamp to view
flywheel poles.
6. Slacken bolt securing CKP sensor bracket to
cylinder block.
7. Position LRT-12-122 to CKP sensor bracket.
Secure with bolt.
8. Push CKP sensor bracket rearwards until tool
contacts flywheel pole.
NOTE: Tool positions bracket allowing for
correct air gap between CKP sensor nose
and flywheel poles.
9. Tighten bolt securing bracket to cylinder block.
10. Remove bolt securing tool to bracket. Remove
tool.
Refit
11. Fit CKP sensor to bracket. Secure with bolt.
Tighten to Max 8 Nm (6 lbf.ft)
12. Connect CKP sensor multiplug.
13. Fit cooling fan cowl. See COOLING SYSTEM,
Repair.
14. Reconnect battery negative lead.
 
damosmokie said:
No there wasn't a spacer like you describe I got a second hand one from Emmotts and they just said to swap the bracket over. They didn't mention a spacer. Have you got any images of this spacer.

The cps can be inserted all the way in till it touches the drive plate so there isn't any shim or spacer.
Click to expand...
oops naughty emmots !
 
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