rodntod

rodntod

Active Member
wondering if someone who has a Nano can answer this.

When you enter the BECM with the key in pos 1 or 2 do your fuel and temp gauges go all the way down,fuel light lit,and after a click from diagnostic connector message centre displays "diagnostic mode".Is this normal?

Datatek is going to try his faulmate to see if this is the same,but i am interested to know if this is normal.

This relates to my NO TEMP GAUGE thread.

Thanks in advance folks.:)
Ed
 
BECM diagnostic mode ignition position II. All gauges should drop to zero fuel warning lamp on. On outputs > Instrument cluster you should get warning lamps page where you can select a check pattern or switch lamps on and off. Next page is fuel and temp gauge test. Where you have Empty, Half, Full and Normal for fuel gauge and Cold, Medium, Hot and Normal for temp gauge. You should be able to drive both to the various positions pressing normal afterwards to return control to car.
 
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wammers said:
BECM diagnostic mode ignition position II. All gauges should drop to zero fuel warning lamp on. On outputs > Instrument cluster you should get warning lamps page where you can select a check pattern or switch lamps on and off. Next page is fuel and temp gauge test. Where you have Empty, Half, Full and Normal for fuel gauge and Cold, Medium, Hot and Normal for temp gauge. You should be able to drive both to the various positions pressing normal afterwards to return control to car.
Click to expand...

Cheers Wammers, yes to all of the above,but heres where it all becomes a little strange.
When i enter Diag mode pos II the only non-working gauge,temp,starts to operate and sits up at 11 o clock.Normally on the very start of gauge.

I can drive fuel gauge to all positions,but can not get the temp gauge to go to cold ,will not go down past the normal position until i exit diagnostics ,then drops back to its non working position.

Its a puzzler, but i know you guys like a puzzle.;)
 
rodntod said:
wondering if someone who has a Nano can answer this.

When you enter the BECM with the key in pos 1 or 2 do your fuel and temp gauges go all the way down,fuel light lit,and after a click from diagnostic connector message centre displays "diagnostic mode".Is this normal?

Datatek is going to try his faulmate to see if this is the same,but i am interested to know if this is normal.

This relates to my NO TEMP GAUGE thread.

Thanks in advance folks.:)
Ed
Click to expand...

OK, when you enter the BECM module, you get the "Diagnostic Mode" message, in the case of the temeprature gauge, assuming the engine is cold, it rises from the rest position to the end of the blue segment and the over temperature light comes on briefly. At this point it's possible to send the gauge to max when the over temp light will come back on, you send it to the middle, and you can send it to minimum, in this case it will only drop to the start of the blue segment, it will not drop to the rest position.
It's not relevant but for reference the fuel light also comes on in diagnostic mode.
On the engine inputs screen, the engine temperature starts at 255 and drops as engine temperature rises, not sure how far it will drop as I only took the engine temperature to 18.2C.
Exiting the BECM module, the diagnostic mode takes a few seconds to go off, at which point the temperature gauge will drop to the rest position.
Hope this helps.:)
 
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Datatek said:
OK, when you enter the BECM module, you get the "Diagnostic Mode" message, in the case of the temeprature gauge, assuming the engine is cold, it rises from the rest position to the end of the blue segment and the over temperature light comes on briefly. At this point it's possible to send the gauge to max when the over temp light will come back on, you send it to the middle, and you can send it to minimum, in this case it will only drop to the start of the blue segment, it will not drop to the rest position.
It's not relevant but for reference the fuel light also comes on in diagnostic mode.
On the engine inputs screen, the engine temperature starts at 255 and drops as engine temperature rises, not sure how far it will drop as I only took the engine temperature to 18.2C.
Exiting the BECM module, the diagnostic mode takes a few seconds to go off, at which point the temperature gauge will drop to the rest position.
Hope this helps.:)
Click to expand...

Cheers Keith,
On my car when you go in to BECM module and enter diag mode, my normally non working temp gauge which was sitting at rest before entering BECM pops up to the normal operating temp point on the gauge as if it was working with the ignition on,while fuel gauge has gone off along with dash lights.
When i then try to drive the temp gauge, i can get it to go upwards past normal but not down to rest.

I cannot understand what makes this gauge behave in a reverse manner to all the other instruments when in BECM diag mode.

Is it possible the Nano is making a better earth to the BECM-temp gauge while in Diag mode??

Bearing in mind my car has has an engine change at some point ,is it possible it has the wrong temp sender or maybe the wrong senders in the wrong places?? ie Gauge sender and EDC temp sender in each others holes??
 
Should have added, when i exit the BECM diag mode and the dash returns to normal all dash lights come back on and fuel gauge slowly rises back to correct fuel level,but bearing in mind key is in pos II, ignition is on, my temp gauge goes back to default position just on the very first blue line,when it should go back to reading engine temp.
 
rodntod said:
Cheers Keith,
On my car when you go in to BECM module and enter diag mode, my normally non working temp gauge which was sitting at rest before entering BECM pops up to the normal operating temp point on the gauge as if it was working with the ignition on,while fuel gauge has gone off along with dash lights.
When i then try to drive the temp gauge, i can get it to go upwards past normal but not down to rest.

I cannot understand what makes this gauge behave in a reverse manner to all the other instruments when in BECM diag mode.

Is it possible the Nano is making a better earth to the BECM-temp gauge while in Diag mode??

Bearing in mind my car has has an engine change at some point ,is it possible it has the wrong temp sender or maybe the wrong senders in the wrong places?? ie Gauge sender and EDC temp sender in each others holes??
Click to expand...

I think your gauge behaviour is normal in diagnostic mode. The other things are normal.
Yes it could be that the Nanaocom is providing an earth path, that's why I suggested earth connections, but relatively unlikely.
Yes it's possible that the sender is the wrong one, but as the BECM engine inputs module does not show a meaningful temperature it's hard to know. I think the figure shown is the digital equivalent of the analogue temperature recorded by the sensor which would make some sense as the figure drops as the sensor resistance drops as temperature rises.
 
rodntod said:
Cheers Keith,
On my car when you go in to BECM module and enter diag mode, my normally non working temp gauge which was sitting at rest before entering BECM pops up to the normal operating temp point on the gauge as if it was working with the ignition on,while fuel gauge has gone off along with dash lights.
When i then try to drive the temp gauge, i can get it to go upwards past normal but not down to rest.

I cannot understand what makes this gauge behave in a reverse manner to all the other instruments when in BECM diag mode.

Is it possible the Nano is making a better earth to the BECM-temp gauge while in Diag mode??

Bearing in mind my car has has an engine change at some point ,is it possible it has the wrong temp sender or maybe the wrong senders in the wrong places?? ie Gauge sender and EDC temp sender in each others holes??
Click to expand...

That is not beyond the bounds of possibility. The ECU sensor should be green and the temp sensor blue.
 
Datatek said:
I think your gauge behaviour is normal in diagnostic mode. The other things are normal.
Yes it could be that the Nanaocom is providing an earth path, that's why I suggested earth connections, but relatively unlikely.
Yes it's possible that the sender is the wrong one, but as the BECM engine inputs module does not show a meaningful temperature it's hard to know. I think the figure shown is the digital equivalent of the analogue temperature recorded by the sensor which would make some sense as the figure drops as the sensor resistance drops as temperature rises.
Click to expand...

Do you think that the temp gauge should be showing a warm engine reading on the needle, in dag mode when all other gauges and dash functions are off?
Does that not seem strange that it is only coming to life when all other dash functions are put to sleep if you like?:confused::)
 
rodntod said:
Do you think that the temp gauge should be showing a warm engine reading on the needle, in dag mode when all other gauges and dash functions are off?
Does that not seem strange that it is only coming to life when all other dash functions are put to sleep if you like?:confused::)
Click to expand...

It's quite possible that the gauge lower position in diagnostic mode will be modified by engine temperature, the engine was cold on mine when testing.
As I said I think all the gauge functions are normal in diagnostic mode.
In the BECM engine inputs screen, it might be worth looking at the temperature figure with the engine cold and watch what happens as you warm the engine up, my guess that the number which will start at around the 255 mark will go down as the temperature rises. I could also check that tomorrow.
 
rodntod said:
Do you think that the temp gauge should be showing a warm engine reading on the needle, in dag mode when all other gauges and dash functions are off?
Does that not seem strange that it is only coming to life when all other dash functions are put to sleep if you like?:confused::)
Click to expand...
I suspect that the diagnostics can drive up by increasing the voltage applied to the gauge but that it cannot drive it lower than the voltage that originated from the sensor. But that still leaves a puzzle as to why if the drive voltage is there it doesn't drive the gauge in normal mode.
 
Any checks you can do would be great Keith thanks.
Just going out to check the colour of the sensor and maybe disconnect it, then plug the nano back in and see where the temp gauge sits when i enter BECM diagnostics.
I suppose it could be a rogue reading if it is the wrong sensor.

I may be totally wrong here but when i tried the nano on yesterday with a warm engine i think i got a coolant temp of 274 or it might have been 247 i will check.
Do all the temp sensors for these engines have a differing ranges of resistance???

Thanks so far guys
Ed:)
 
rodntod said:
Any checks you can do would be great Keith thanks.
Just going out to check the colour of the sensor and maybe disconnect it, then plug the nano back in and see where the temp gauge sits when i enter BECM diagnostics.
I suppose it could be a rogue reading if it is the wrong sensor.

I may be totally wrong here but when i tried the nano on yesterday with a warm engine i think i got a coolant temp of 274 or it might have been 247 i will check.
Do all the temp sensors for these engines have a differing ranges of resistance???

Thanks so far guys
Ed:)
Click to expand...

Quite likely, never checked. They are what are called negative temperature coefficient resistors, resistance drops as temperature rises:)
 
Datatek said:
I suspect that the diagnostics can drive up by increasing the voltage applied to the gauge but that it cannot drive it lower than the voltage that originated from the sensor. But that still leaves a puzzle as to why if the drive voltage is there it doesn't drive the gauge in normal mode.
Click to expand...

And what if the wrong sensor was not sending a sufficient voltage to drive the gauge in normal mode,due to wrong resistance range???
 
rodntod said:
And what if the wrong sensor was not sending a sufficient voltage to drive the gauge in normal mode,due to wrong resistance range???
Click to expand...

It's a bit more complicated than that (not to mention stupid) The analogue voltage from the sensor is converted to a digital number in the BECM, at some point the digital number is converted back to a voltage to drive the gauge, not sure if this is done by the dash processor or the BECM as I haven't looked it up.
However if the voltage from the sensor is way out of kilter it may cause some strange effects depending on how good the BECM software is at coping with unintended situations:)
 
Sensor for EDC ECU is green. Sensor for dash temp up to chassis number WA400481 (1998) was light brown. Single terminal. Sensor from WA 400482 and up. Blue twin terminal. Even if it's an earlier engine it needs the blue sensor if chassis number is greater than WA400482 to match circuits to BECM. On a 2001 model sensor should be blue.
 
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A bit more investigation has shown that the engine temperature sensor reading in the BECM is a digital value between 0 and 255, it would seem that BBS do not convert this figure to a temperature. So as the engine warms up you should see the number drop. I'm not sure the sensors are linear but for the gauge to be half way I would be looking for a number in the range 120 to 170 with an engine temperature in the EDC of around 85C.
I think Wammers info on the sensor is the first thing to check, if the sensor is correct, then run the engine up to temperature and note the number as suggested above.
 
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Data,wammers, you guys are amazingly good at this.:)

Just been back out and plugged in.
I see what you mean Keith ,even with the sensor unplugged i get a reading of 255.
Now the thing is,when i go back to the BECM diagnostics,with the sensor unplugged,the temp gauge still goes up as everything else goes off.And it still goes to where i would think would be correct for the engines current temp(EDC is showing 25 degrees).
And still can not send it to the cold setting even though the sensor is unplugged???
And the big news is..........my temp gauge sensor is 2 pin and is BLACK!!!
 
rodntod said:
Data,wammers, you guys are amazingly good at this.:)

Just been back out and plugged in.
I see what you mean Keith ,even with the sensor unplugged i get a reading of 255.
Now the thing is,when i go back to the BECM diagnostics,with the sensor unplugged,the temp gauge still goes up as everything else goes off.And it still goes to where i would think would be correct for the engines current temp(EDC is showing 25 degrees).
And still can not send it to the cold setting even though the sensor is unplugged???
And the big news is..........my temp gauge sensor is 2 pin and is BLACK!!!
Click to expand...


I would not worry about not being able to send the gauge to the cold setting, I can't on mine. Gauges are not that precise so yours is a bit different to mine but not by a lot.
Could be wrong sensor, need to watch the figures as the engine warms as I suggested.
 
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