TEMS Lights

ynnek · 08-04-2010, 07:47 PM

All 3 indicator lights light up if I turn on my head lights & stay on until I turn off the head lights. The kicker is, if I turn on my lights first, then crank my car, the TEMS selection buttons & dash indicator light funtion properly. Any help on this subject would be greatly appricated.

Green7mgte · 08-04-2010, 08:31 PM

lol thats odd.

heres the trouble shooting guide for tems

http://www.cygnusx1.net/Supra/Librar...aspx?S=FA&P=30

cre · 08-05-2010, 01:42 AM

Very odd indeed. Is there any aftermarket interior lighting installed? EL gauged in particular....?

Confusing speculative, not completely thought out banter to follow:

The two circuits aren't connected at all. There is no illum/dim integration for this display (one of the only lighted circuits like this in the MKIII, the only other being the light switch indicator).

I can't find the blue TEMS display I've got somewhere around here for reference, but I believe the black wire chould be ground full time and the red, blue and green wires positive only depending on the TEMS controller's response. Which leaves us two possibilities to explore: The TEMS is active full time when the three are lit up (this is unlikely as ALL three conductors would have to be shorted across a positive signal) OR there's a bridged wire in the cluster or harness. Are you sure the TEMS isn't going full firm when the three lights light up? If so the bridge would be at one of the signal input lines (SPD, SS1, SS2 or VS).

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=115

Sorry if this is confusing.... in short, there's no easy way for this to be occuring, but the more likely of the unlikely is that one of the input signal lines is shorted to a positive.... wierd.

cre · 08-05-2010, 01:45 AM

Just to make sure there's no short across the cluster illumination wiring, unplug the dimmer and pull the gauge out as far as you can while it's still plugged in. Test for continuity across the white/green stripe wire at the dimmer harness and each of the four wires from the TEMS display.

ynnek · 08-05-2010, 12:18 PM

I will get around to checking these a bit later, as is has been over 100 degrees for several days here in Memphis. Once I get home from work I just want to sit in the AC for a while.

ynnek · 10-07-2010, 01:16 PM

was coinciding with this problem. I replaced all of my bulbs, & tightened all of the grounding screws & the problem went away.

I did not think these two systems had anything to do with one another. Oh well, everything is ok now.

08-04-2010, 07:47 PM	#1
ynnek Stock Join Date: Aug 2009 Location: Memphis, TN Posts: 14	TEMS Lights All 3 indicator lights light up if I turn on my head lights & stay on until I turn off the head lights. The kicker is, if I turn on my lights first, then crank my car, the TEMS selection buttons & dash indicator light funtion properly. Any help on this subject would be greatly appricated.

08-04-2010, 08:31 PM	#2
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	lol thats odd. heres the trouble shooting guide for tems http://www.cygnusx1.net/Supra/Librar...aspx?S=FA&P=30 __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 08-04-2010 at 08:33 PM.

08-05-2010, 01:42 AM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Very odd indeed. Is there any aftermarket interior lighting installed? EL gauged in particular....? Confusing speculative, not completely thought out banter to follow: The two circuits aren't connected at all. There is no illum/dim integration for this display (one of the only lighted circuits like this in the MKIII, the only other being the light switch indicator). I can't find the blue TEMS display I've got somewhere around here for reference, but I believe the black wire chould be ground full time and the red, blue and green wires positive only depending on the TEMS controller's response. Which leaves us two possibilities to explore: The TEMS is active full time when the three are lit up (this is unlikely as ALL three conductors would have to be shorted across a positive signal) OR there's a bridged wire in the cluster or harness. Are you sure the TEMS isn't going full firm when the three lights light up? If so the bridge would be at one of the signal input lines (SPD, SS1, SS2 or VS). http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=115 Sorry if this is confusing.... in short, there's no easy way for this to be occuring, but the more likely of the unlikely is that one of the input signal lines is shorted to a positive.... wierd. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

08-05-2010, 01:45 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Just to make sure there's no short across the cluster illumination wiring, unplug the dimmer and pull the gauge out as far as you can while it's still plugged in. Test for continuity across the white/green stripe wire at the dimmer harness and each of the four wires from the TEMS display. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

08-05-2010, 12:18 PM	#5
ynnek Stock Join Date: Aug 2009 Location: Memphis, TN Posts: 14	Thanks for the replies I will get around to checking these a bit later, as is has been over 100 degrees for several days here in Memphis. Once I get home from work I just want to sit in the AC for a while.

10-07-2010, 01:16 PM	#6
ynnek Stock Join Date: Aug 2009 Location: Memphis, TN Posts: 14	Tail Light problem was coinciding with this problem. I replaced all of my bulbs, & tightened all of the grounding screws & the problem went away. I did not think these two systems had anything to do with one another. Oh well, everything is ok now.

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