No temp gauge

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Carpet is bone dry(at the moment). Its looking that way.Seat out tomorrow and check the relevant plug on the BECM.

When i used the variable resistor i could get the overheat light to come on but still no needle movement :confused::confused:
Will let you know when i finally find it,cheers.
 
rodntod said:
Carpet is bone dry(at the moment). Its looking that way.Seat out tomorrow and check the relevant plug on the BECM.

When i used the variable resistor i could get the overheat light to come on but still no needle movement :confused::confused:
Will let you know when i finally find it,cheers.
Click to expand...

Ok you got high temp lamp on. Don't think that is a separate circuit so it at least proves BECM is feeding gauge. When you do the check with Nanocom it takes a considerable time for needle to move as it is damped. Did you allow sufficient time or just wind pot up and down?
 
wammers said:
Ok you got high temp lamp on. Don't think that is a separate circuit so it at least proves BECM is feeding gauge. When you do the check with Nanocom it takes a considerable time for needle to move as it is damped. Did you allow sufficient time or just wind pot up and down?
Click to expand...


Wammers, i did have my son in the drivers seat checking the gauge and reporting the happenings,and although i didnt wait any more than maybe 10 seconds from dialling the resistor down ,the gauge still had not moved from the bottom blue line?

I think i put it it an earlier post but i was a bit naughty at the beginning and looped the sensor plug without a resistor,which immediately brought the overheat light on and along with a beep on the dash,informed. me i had a Faulty temp gauge on the message centre.:confused::confused:
Didnt even know that message existed ,but there you go.
 
rodntod said:
Wammers, i did have my son in the drivers seat checking the gauge and reporting the happenings,and although i didnt wait any more than maybe 10 seconds from dialling the resistor down ,the gauge still had not moved from the bottom blue line?

I think i put it it an earlier post but i was a bit naughty at the beginning and looped the sensor plug without a resistor,which immediately brought the overheat light on and along with a beep on the dash,informed. me i had a Faulty temp gauge on the message centre.:confused::confused:
Didnt even know that message existed ,but there you go.
Click to expand...

In that case try leaving it longer it takes some time to move from one position to the other. Shorting the plug may have given you a fault code that needs deleting before what BECM thinks is a duff gauge will work again. Worth a try. Think the bucket of worms is well and truly open though.
 
wammers said:
In that case try leaving it longer it takes some time to move from one position to the other. Shorting the plug may have given you a fault code that needs deleting before what BECM thinks is a duff gauge will work again. Worth a try. Think the bucket of worms is well and truly open though.
Click to expand...

The BECM does not log any fault codes.
It does take a long time for the gauge to move.
Was the message duff gauge or duff sensor? Not sure how the system could know you have a duff gauge unless it is completely open circuit, but it could report an out of limits sender.
 
wammers said:
Think 4.5 to 5 volts is right for feed. Sensor changes this voltage according to temp. If you take sensor out connect up and hold a cigarette lighter near the bulb gauge should rise pretty quickly, if it doesn't sensor is duff. Gauge can be checked for function if you know someone with a Nanocom.
Click to expand...

Being the Logical being I am what would the point of removing the sensor to light with a lighter when presuming there is enough water in the head for the sensor to register in the first place , I thought the point of removing the sensor is to disconnect from the gauge Wires and to independently try the sensor with a meter reading device ?? By leaving it connected and no movement of the cars gauge would not tell weather the gauge or sensor is at fault, but by
Separating the sensor away from car and testing with a heat source would tell you that the sensor alone is duff . It's the voices I can't help myself:)
 
defender300td1 said:
Being the Logical being I am what would the point of removing the sensor to light with a lighter when presuming there is enough water in the head for the sensor to register in the first place , I thought the point of removing the sensor is to disconnect from the gauge Wires and to independently try the sensor with a meter reading device ?? By leaving it connected and no movement of the cars gauge would not tell weather the gauge or sensor is at fault, but by
Separating the sensor away from car and testing with a heat source would tell you that the sensor alone is duff . It's the voices I can't help myself:)
Click to expand...

He could always run the engine and do that. Why remove sensor and loose coolant if you don't have to. Engine will run quite happily without manifold fitted. Think at that point he had said sensor was out.
 
Last edited:
wammers said:
He could always run the engine and do that. Why remove sensor and loose coolant if you don't have to. Engine will run quite happily without manifold fitted. Think at that point he had said sensor was out.
Click to expand...

I know my point is testing it with the cars gauge that's what you said .
 
defender300td1 said:
I know my point is testing it with the cars gauge that's what you said .
Click to expand...

Ok i see what you mean but gauges are not the usual thing that goes duff. He knew he had power to the sensor. If he had the sensor out and put a lighter to the bulb and the gauge did not move, then checked the sensor by connecting to meter and used the lighter again and the sensor changed resistance he would know where to look next. No need for a pan of water. Of course if the sensor was still in he could run engine and do same check.
 
wammers said:
Ok i see what you mean but gauges are not the usual thing that goes duff. He knew he had power to the sensor. If he had the sensor out and put a lighter to the bulb and the gauge did not move, then checked the sensor by connecting to meter and used the lighter again and the sensor changed resistance he would know where to look next. No need for a pan of water. Of course if the sensor was still in he could run engine and do same check.
Click to expand...

Might of needed water if he used oxygen/acetylene tho
 
Ok guys a quick re-cap and update.

Sensor has been checked on car and off car,with lighter ,hot water,multimeter.Showing resistance of around 9k ohms (cold) dropping to around 1.2k ohms when heated by the various methods above.

wiring is showing 4.3v??? with ignition on, and good earth on other wire to sensor plug.

by shorting out the sensor plug with a wire loop,overheat warning light comes on and message Temp gauge fault or faulty is displayed in message centre.

by looping the sensor plug ,this time with a variable resistor(old stereo vol control) i can dial it from 8k ohms down to 0.3k ohms but still no needle movement.

Took drivers seat out this morning,expecting to find dampness or corrosion on BECM plug c1289 -20 pin green-as this plug seems to be the one related to ECT and coincidentally, low screen wash message which i always get when i turn the ign on??

And guess what i found when i got in there...........................and old Ribena carton,kids sock ,45p and 3 dodgy looking jelly babies :D:D,
but no dodgy connections or signs of dampness or corrosion,BUGGER.
Keep the suggestions coming lads.
Gonna try and get it on diagnostics and see what we get there,though i have read a thread identical to this on another site and even though they could operate the needle on diagnostics ,they could never get to the bottom of it :confused::confused:.
But hey ,absolutely everything else works on the car so what am i complaining about.
Sorry for the length of the post ;):)
 
rodntod said:
Ok guys a quick re-cap and update.

Sensor has been checked on car and off car,with lighter ,hot water,multimeter.Showing resistance of around 9k ohms (cold) dropping to around 1.2k ohms when heated by the various methods above.

wiring is showing 4.3v??? with ignition on, and good earth on other wire to sensor plug.

by shorting out the sensor plug with a wire loop,overheat warning light comes on and message Temp gauge fault or faulty is displayed in message centre.

by looping the sensor plug ,this time with a variable resistor(old stereo vol control) i can dial it from 8k ohms down to 0.3k ohms but still no needle movement.

Took drivers seat out this morning,expecting to find dampness or corrosion on BECM plug c1289 -20 pin green-as this plug seems to be the one related to ECT and coincidentally, low screen wash message which i always get when i turn the ign on??

And guess what i found when i got in there...........................and old Ribena carton,kids sock ,45p and 3 dodgy looking jelly babies :D:D,
but no dodgy connections or signs of dampness or corrosion,BUGGER.
Keep the suggestions coming lads.
Gonna try and get it on diagnostics and see what we get there,though i have read a thread identical to this on another site and even though they could operate the needle on diagnostics ,they could never get to the bottom of it :confused::confused:.
But hey ,absolutely everything else works on the car so what am i complaining about.
Sorry for the length of the post ;):)
Click to expand...
If it comes to the crunch you can always wire in your own gauge it is after all one of the most important ones
 
rodntod said:
Ok guys a quick re-cap and update.

Sensor has been checked on car and off car,with lighter ,hot water,multimeter.Showing resistance of around 9k ohms (cold) dropping to around 1.2k ohms when heated by the various methods above.

wiring is showing 4.3v??? with ignition on, and good earth on other wire to sensor plug.

by shorting out the sensor plug with a wire loop,overheat warning light comes on and message Temp gauge fault or faulty is displayed in message centre.

by looping the sensor plug ,this time with a variable resistor(old stereo vol control) i can dial it from 8k ohms down to 0.3k ohms but still no needle movement.

Took drivers seat out this morning,expecting to find dampness or corrosion on BECM plug c1289 -20 pin green-as this plug seems to be the one related to ECT and coincidentally, low screen wash message which i always get when i turn the ign on??

And guess what i found when i got in there...........................and old Ribena carton,kids sock ,45p and 3 dodgy looking jelly babies :D:D,
but no dodgy connections or signs of dampness or corrosion,BUGGER.
Keep the suggestions coming lads.
Gonna try and get it on diagnostics and see what we get there,though i have read a thread identical to this on another site and even though they could operate the needle on diagnostics ,they could never get to the bottom of it :confused::confused:.
But hey ,absolutely everything else works on the car so what am i complaining about.
Sorry for the length of the post ;):)
Click to expand...

On CO1289. Pin 20 is engine speed pin 19 is temp input. But unless i am blind i cannot find an output to gauge.
 
4.3 Volts is the Line Voltage from the BeCM.....don't expect to see 12V cos you won't btw!

Usual discrete/line voltage is around the 5v mark.

You're not going blind Tony - no mention of the pin out to the Instrument diplay from the BeCM - all other lamps and gauges except the Coolant gauge....could this be to stop people from bridging this out to hide an overheat before selling it??
 
Addundum to the above:

But then again Connector C242 connector diagram....

Go through the Instrument and Warnings Sections - cross off the ones mentioned from the pin out diagram, whats left must be the ones not mentioned for the Temp Gauge - process of elimination surely!!
 
Saint.V8 said:
4.3 Volts is the Line Voltage from the BeCM.....don't expect to see 12V cos you won't btw!

Usual discrete/line voltage is around the 5v mark.

You're not going blind Tony - no mention of the pin out to the Instrument diplay from the BeCM - all other lamps and gauges except the Coolant gauge....could this be to stop people from bridging this out to hide an overheat before selling it??
Click to expand...

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.
 
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