Upshift indicator
07-17-2011, 11:53 AM
#1
Racer
Thread Starter
Upshift indicator
I am trying to troubleshoot the upshift indicator on my '87 Targa.
Sometimes it works and other times the light does not come on regardless of what I try. Has anyone had this issue and how did you address it?
In advance, thanks
Glenn
Sometimes it works and other times the light does not come on regardless of what I try. Has anyone had this issue and how did you address it?
In advance, thanks
Glenn
07-17-2011, 12:29 PM
#2
Most people want this "feature" disabled and don't mind if it doesn't work. You can completely disable it by unplugging and taping the black wire on the tachometer.
The light seems to be activated when you have a slightly-open, constant throttle over 2k rpms
If you are changing throttle position, then the light goes out.
The light also serves as a rev-limiter indicator. Does it come on when you hit the redline?
The upshift light is directly driven by the ECU. There is not much to troubleshoot outside of making sure the connections are solid or the throttle position switches are functioning correctly..... And your grounds are solid.
The light seems to be activated when you have a slightly-open, constant throttle over 2k rpms
If you are changing throttle position, then the light goes out.
The light also serves as a rev-limiter indicator. Does it come on when you hit the redline?
The upshift light is directly driven by the ECU. There is not much to troubleshoot outside of making sure the connections are solid or the throttle position switches are functioning correctly..... And your grounds are solid.
07-17-2011, 02:48 PM
#3
Instructor
Join Date: Jul 2009
Location: Manhattan Beach, California. Retired Engineer 1986 Targa-Factory Delivery Original Owner
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Here is the circuit from my "well loved" 1986 factory manual.
I would be looking at:
1. The connections on the back of the Tachometer.
2. The connections at the DME connector.
Hope this helps.
Gerry
07-17-2011, 10:51 PM
#5
Racer
Thread Starter
Gerry,
Much thanks. I will start troubleshooting.
"Most people want this "feature" disabled and don't mind if it doesn't work. You can completely disable it by unplugging and taping the black wire on the tachometer."
Yes, I generally agree ... but it is also important to me that EVERYTHING works. Just the way that I am.
"The light seems to be activated when you have a slightly-open, constant throttle over 2k rpms
If you are changing throttle position, then the light goes out. "
I understand ... and this is what got me so puzzled. Sometimes it just works (same speed, barely touching the throttle - very little to no load on the engine)
and sometimes not. Sometimes, when the engine gets a bit hotter (e.g. just over the first white line), it all of a sudden begins to work and sometimes it just doesn't.
I just gotta fix it ... if I even pass on the car on, it is important for me to say that everything works
Thanks for the replies gentlemen
Glenn
Much thanks. I will start troubleshooting.
"Most people want this "feature" disabled and don't mind if it doesn't work. You can completely disable it by unplugging and taping the black wire on the tachometer."
Yes, I generally agree ... but it is also important to me that EVERYTHING works. Just the way that I am.
"The light seems to be activated when you have a slightly-open, constant throttle over 2k rpms
If you are changing throttle position, then the light goes out. "
I understand ... and this is what got me so puzzled. Sometimes it just works (same speed, barely touching the throttle - very little to no load on the engine)
and sometimes not. Sometimes, when the engine gets a bit hotter (e.g. just over the first white line), it all of a sudden begins to work and sometimes it just doesn't.
I just gotta fix it ... if I even pass on the car on, it is important for me to say that everything works
Thanks for the replies gentlemen
Glenn
