No temp gauge

Grit Valve · Oct 3, 2012

wammers said:
Or it could be a bloody great error by Land rover technical. Connections not shown on wiring diagrams either. Only thing to do would be remove instrument pack and continuity test inputs to it.

I do belive the alternator is tied in somewhere as you should see what how much the needle of the gauge fluctuates when the alternator is playing up or the tensioner that drives it mine used to go wild

wammers · Oct 3, 2012

defender300td1 said:
I do belive the alternator is tied in somewhere as you should see what how much the needle of the gauge fluctuates when the alternator is playing up or the tensioner that drives it mine used to go wild

That is because systems are powered direct from the alternator when engine is running. That is why you get all sorts of fault messages if it is on the blink.

Grit Valve · Oct 3, 2012

wammers said:
That is because systems are powered direct from the alternator when engine is running. That is why you get all sorts of fault messages if it is on the blink.

Could this Be included into one of the factors then if so any way of checking

wammers · Oct 3, 2012

defender300td1 said:
Could this Be included into one of the factors then if so any way of checking

Don't think so, the temp gauge should work off the battery with ignition on before engine is started. If alternator was a problem there would be a lot more not working than just the temp gauge.

Datatek · Oct 3, 2012

wammers said:
Or it could be a bloody great error by Land rover technical. Connections not shown on wiring diagrams either. Only thing to do would be remove instrument pack and continuity test inputs to it.

Or it could be that the info is sent to the dash ECU in digital form on the comms lines. Stupid but possible.

With diagnostics, it's possible to excercise the gauge and also to monitor the sensor, if the sensor reads correctly and the gauge operates with diagnostics it might come down to a problem with the BECM.

rodntod · Oct 3, 2012

Datatek said:
Or it could be that the info is sent to the dash ECU in digital form on the comms lines. Stupid but possible.

With diagnostics, it's possible to excercise the gauge and also to monitor the sensor, if the sensor reads correctly and the gauge operates with diagnostics it might come down to a problem with the BECM.

Think you might be on to something Keith.

The other thread i have been reading concludes with the expert saying he can see no output to gauge from BECM after all his searching, and implies it might change to serial data rather than voltage to feed the needle?????

Datatek · Oct 3, 2012

rodntod said:
Think you might be on to something Keith.

The other thread i have been reading concludes with the expert saying he can see no output to gauge from BECM after all his searching, and implies it might change to serial data rather than voltage to feed the needle?????

It's quite likely that the comms lines are used to send digital temperature data to the dash. The analogue input from the sensor is converted to digital by an A to D convertor in the BECM from what I have read so it would be easy to transfer the digital temperature to the dash then re convert to analogue to drive the gauge,
However, if the sensor can be read with diagnostics, that means the A to D convertor and the lines into the CPU are OK. If the gauge can be driven from diagnostics then the comms link from the CPU to the dash must be OK.
That leaves something internal like a software corruption in the BECM controlling the transfer of the data from the input to the output.
I hope it doesn't come to that.

rodntod · Oct 3, 2012

Datatek said:
It's quite likely that the comms lines are used to send digital temperature data to the dash. The analogue input from the sensor is converted to digital by an A to D convertor in the BECM from what I have read so it would be easy to transfer the digital temperature to the dash then re convert to analogue to drive the gauge,
However, if the sensor can be read with diagnostics, that means the A to D convertor and the lines into the CPU are OK. If the gauge can be driven from diagnostics then the comms link from the CPU to the dash must be OK.
That leaves something internal like a software corruption in the BECM controlling the transfer of the data from the input to the output.
I hope it doesn't come to that.

You and me both

Will report back once i get the diagnostics done.

Thanks a million for all the help so far guys,greatly appreciated

Ed

Datatek · Oct 3, 2012

OK, RAVE confirms that all info for the dash is sent from the BECM via the serial comms lines.

rodntod · Oct 3, 2012

Datatek said:
OK, RAVE confirms that all info for the dash is sent from the BECM via the serial comms lines.

Thanks Keith,lets hope the diagnostics will come up with something

gencybay · Oct 4, 2012

Datatek said:
OK, RAVE confirms that all info for the dash is sent from the BECM via the serial comms lines.

That's interesting. I thought that the instrument cluster was straight out of a BMW. If that is the case, there might be some BMW documentation that provides further insight into the mysterious BECM.

G~

Here

http://www.bmw-m.net/TechProc/test.htm

Saint.V8 · Oct 4, 2012

gencybay said:
That's interesting. I thought that the instrument cluster was straight out of a BMW. If that is the case, there might be some BMW documentation that provides further insight into the mysterious BECM.

G~

Here

instrument cluster test

The L322 Is pretty much a E38 7'er with bits of the E39 5'er and the X5 thrown in to confuse the situation - but the P38 is pretty much all Land Rover bar the M51 Diesel Engine I believe.

The Test you detail does work on the L322 - as I have done this to monitor coolant temp readings!!

rodntod · Oct 4, 2012

Update.
Just spoken to Jimsnapon,and looks like Sunday will be spent plugged in to his gadgets and maybe we will get a result!!!

wammers · Oct 4, 2012

Hope you sort it Rod. Keith is top knob on lectricery. Although his nipple clamps hurt like hell according to Ants missus.

rodntod · Oct 4, 2012

wammers said:
Hope you sort it Rod. Keith is top knob on lectricery. Although his nipple clamps hurt like hell according to Ants missus.

:hysterically_laughi:hysterically_laughi
Cheers Wammers,will keep you all updated .

Saint.V8 · Oct 4, 2012

wammers said:
Hope you sort it Rod. Keith is top knob on lectricery. Although his nipple clamps hurt like hell according to Ants missus.

And she won't let me hear the end of it...."Why don't your clamps pinch as hard as Keiths, even Tony's are firmer than yours, I think you need to get on that forum and ask them where they got their clamps from....blah blah blah...."

rodntod · Oct 23, 2012

Just a quick update folks,
Had a diagnostic done on the car today to try and trace the fault.
He was able to read engine temp,lift sensor,throttle pot ,air temp etc.
My question is, is he getting these readings from the engine ECU only,as he was unable to access any instrument testing and could not drive the gauges manually?
Or is it only the BECM that the temp can be read from?
Is it just another case of the p38 being too difficult to access without a bespoke diagnostic.
Another 30 quid on to the price of my inevitable purchase of a Nanocom,i suppose.!!!

wammers · Oct 23, 2012

rodntod said:
Just a quick update folks,
Had a diagnostic done on the car today to try and trace the fault.
He was able to read engine temp,lift sensor,throttle pot ,air temp etc.
My question is, is he getting these readings from the engine ECU only,as he was unable to access any instrument testing and could not drive the gauges manually?
Or is it only the BECM that the temp can be read from?
Is it just another case of the p38 being too difficult to access without a bespoke diagnostic.
Another 30 quid on to the price of my inevitable purchase of a Nanocom,i suppose.!!!

What unit did he do the test with?

Datatek · Oct 23, 2012

I'm pretty sure that the gauges can be driven from Faultmate and the sensors can be read.

wammers · Oct 23, 2012

Datatek said:
I'm pretty sure that the gauges can be driven from Faultmate and the sensors can be read.

Faultmate must be able to do that Nanocom can.

No temp gauge

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