'90 MY "shift light" ? - ZR-1 Net Registry Forums

WVZR-1 · 05-07-2014

From a conversation over in the CF for an L98 BUT after checking the FSM for the LT5 the instrument cluster mentions an "upshift light/tell tale" (NOT RELATED TO 1 - 4). The 90 FSM it's in 8A-22-A and you'll see both shift and the 1 - 4. I've never seen it on mine but my spare cluster has a bulb socket in the correct position. I didn't remove the backing plate to check and likely won't to see if there's a bulb. The bulb placement is on 8C-33 #12.

Was it maybe never implemented and just an engineering thought? Anyone seen it actually work? I don't recall it ever being discussed. In the L98 schematic there even seems to be a provision for an "overdrive" lamp.

I don't see it in the '91 FSM in a similar location but I didn't look very hard. The cluster illumination on 8C-42 still has reference to it though.

Kevin · 05-07-2014

the upshift light is in the dash cluster near the top left if I remember correctly. I have have marc redo my chip to get it put back in. last time i saw it was in 06 I THINK 90 is the only year to have it

8cam · 05-07-2014

GM's updated calibration for the '90 actually disabled the shift light, so it might have been there from the factory but was removed with a service update. Marc has the details on his site.

http://www.zr1specialist.com/HAT%20W...on%20AYBKG.htm

WVZR-1 · 05-07-2014

Can't imagine my not knowing/remembering that but sh!t happens I guess. I thought I had notes for all of the early revisions to the PROM. Guess I'll not be concerned.

gbrtng · 05-07-2014

I see that indication on my 91 when I stay in a lower gear for an extended time - example = driving in 5th for several minutes at (say) 60 MPH. There is also a 1 to 4 indication ...

WVZR-1 · 05-07-2014

Quote:

Originally Posted by gbrtng

I see that indication on my 91 when I stay in a lower gear for an extended time - example = driving in 5th for several minutes at (say) 60 MPH. There is also a 1 to 4 indication ...

I didn't find it in the FSM in a similar location as the '90MY information. Have you seen it in the wiring for the ECM for your '91? Is it mentioned in your owners manual? The upshift isn't related to the 1-4

05-07-2014	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,633	Re: '90 MY "shift light" ? the upshift light is in the dash cluster near the top left if I remember correctly. I have have marc redo my chip to get it put back in. last time i saw it was in 06 I THINK 90 is the only year to have it __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

05-07-2014	#3
8cam Join Date: Jul 2013 Location: Atlanta Posts: 451	Re: '90 MY "shift light" ? GM's updated calibration for the '90 actually disabled the shift light, so it might have been there from the factory but was removed with a service update. Marc has the details on his site. http://www.zr1specialist.com/HAT%20W...on%20AYBKG.htm __________________ Mark '90 ZR-1 #1322 Daily Driver, 64k and counting Black/Gray [IMG]http://i208.photobucket.com/albums/bb49/mlitherland/IMG_0326_zps3d50d8cb.jpg[/IMG]

05-07-2014	#4
WVZR-1 Join Date: Oct 2004 Posts: 1,889	Re: '90 MY "shift light" ? Can't imagine my not knowing/remembering that but sh!t happens I guess. I thought I had notes for all of the early revisions to the PROM. Guess I'll not be concerned.

05-07-2014	#5
gbrtng Join Date: Feb 2006 Location: San Antonio area Posts: 1,179	Re: '90 MY "shift light" ? I see that indication on my 91 when I stay in a lower gear for an extended time - example = driving in 5th for several minutes at (say) 60 MPH. There is also a 1 to 4 indication ... __________________ “Buy the best example of what you want, and pay whatever it takes. That way, you cry only once.” ~ Bruce Meyer

05-07-2014	#1
WVZR-1 Join Date: Oct 2004 Posts: 1,889	'90 MY "shift light" ? From a conversation over in the CF for an L98 BUT after checking the FSM for the LT5 the instrument cluster mentions an "upshift light/tell tale" (NOT RELATED TO 1 - 4). The 90 FSM it's in 8A-22-A and you'll see both shift and the 1 - 4. I've never seen it on mine but my spare cluster has a bulb socket in the correct position. I didn't remove the backing plate to check and likely won't to see if there's a bulb. The bulb placement is on 8C-33 #12. Was it maybe never implemented and just an engineering thought? Anyone seen it actually work? I don't recall it ever being discussed. In the L98 schematic there even seems to be a provision for an "overdrive" lamp. I don't see it in the '91 FSM in a similar location but I didn't look very hard. The cluster illumination on 8C-42 still has reference to it though.