8D code for shift light
Thread Starter
Supreme Member
Joined: Jan 2002
Posts: 1,162
Likes: 1
From: California
Car: Z28
Engine: L98
Transmission: T56
8D code for shift light
I'm posting this while it's fresh in my memory in case it's useful to anyone.
I wanted a shift light based in the factory computer, to do one and only one thing: turn on above RPM (X), and turn off below RPM (X).
I studied ANHT a bit, and came to the conclusion that the code between 5F7D and 6003 (as seen in a hex editor when directly editing my AXXD .BIN - keep in mind ANHT is offset!!), all dealt with the factory shift light code. I didn't want any of that crud, so I 01'd the whole section ("no op"), and replaced it as follows:
I reused the value at 035B (835B to the ecm) to control the shift light RPM, which I then entered into tunercat's TDF editor in my custom TDF.
So far, I've tested it on the bench and it seems to work exactly as designed....
the plan from here is to get a bright LED (or multiple LEDs), run them through the appropriate current limiting resistor, then hang them off the shift light pin of my '730. Last time I was at summit, autometer (I think?) had a fairly nice, thin shift light which could also be used, but I think I want to stealth in some LED's somewhere so that they are inconspicous until they light up. Will be using some sort of ultrabright LED so that the thing is plainly visible even under noon sunlight (what good is it if ya can't see it?)
next up is going to be code to handle the t56 reverse lockout solenoid.
I wanted a shift light based in the factory computer, to do one and only one thing: turn on above RPM (X), and turn off below RPM (X).
I studied ANHT a bit, and came to the conclusion that the code between 5F7D and 6003 (as seen in a hex editor when directly editing my AXXD .BIN - keep in mind ANHT is offset!!), all dealt with the factory shift light code. I didn't want any of that crud, so I 01'd the whole section ("no op"), and replaced it as follows:
Code:
5F7D LDAA L0085 5F7F LDX #$835B ; RPM FOR SHIFT LITE 5F82 CMPA 0,X 5F84 BLS +05 5F86 BSET L0038,#$80 ; SET b7, SHIFT LIGHT ON 5F89 BRA +03 5F8B BCLR L0038,#$80 ; CLR b7, SHFT LIGHT *OFF*
So far, I've tested it on the bench and it seems to work exactly as designed....
the plan from here is to get a bright LED (or multiple LEDs), run them through the appropriate current limiting resistor, then hang them off the shift light pin of my '730. Last time I was at summit, autometer (I think?) had a fairly nice, thin shift light which could also be used, but I think I want to stealth in some LED's somewhere so that they are inconspicous until they light up. Will be using some sort of ultrabright LED so that the thing is plainly visible even under noon sunlight (what good is it if ya can't see it?)
next up is going to be code to handle the t56 reverse lockout solenoid.
Supreme Member
Joined: Feb 2002
Posts: 2,663
Likes: 9
From: Buckhannon, WV
Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
Neat little setup you got there, I did a similar setup on my fiance' car only using the neanderthaw methode. We just hacked up a proform shift light. We hid the dial in the ashtray and hid three little LED's in the dash. We used super bright blue LEDs from radio shack and man are those things bright. We actually had to wire in a resistor on a switch to tone them down at night. You can't see the road when they kick on! 
Supreme Member
Joined: Jul 1999
Posts: 1,577
Likes: 0
From: Baton Rouge, LA, USA
Car: 87 T/A
Engine: 441 SBC 12.5:1 0.680" Lift
Transmission: T-56
Axle/Gears: 4.10 TruTrac Moser 9"
I'd be interested to hear about your reverse lockout accomplishments as well when you get there.
By the way, how about RPM resolution up top for the 730? What if you wanted to shift at 7000?
By the way, how about RPM resolution up top for the 730? What if you wanted to shift at 7000?
Senior Member
Joined: Jun 2000
Posts: 998
Likes: 0
From: Tuscaloosa, AL
Car: 91Z, 91RS, '84 Jimmy
Engine: L98, 355, L98
Transmission: 700R, T56, 700R4
Reverse lockout should be easy enough. Just check current MPH against a max. value (say 5 or so) and enable reverse when below that threshold. That's how the 4th gens do it stock, IIRC. Finding a good place to put it in the current code will be harder than writing the algorythm, although it looks like you opened up plenty of space when you pulled the stock shiftlight stuff.
This is something I had in mind to play with when I get my "test bed" car converted back to EFI.
I had some ideas about the shiftlight too.....I know a few guys who like to shift 1-2 at a different RPM than the rest of the gears for traction reasons....you could set the code up for that as well. Use the NV ratio to determine what gear it's in, and then lookup the shiftlight threshold based on that. Just a simple "if NV > X then use A threshold, if NV < X use B threshold." If you like the same RPM all the time just use the same value for A and B.
This is something I had in mind to play with when I get my "test bed" car converted back to EFI.
I had some ideas about the shiftlight too.....I know a few guys who like to shift 1-2 at a different RPM than the rest of the gears for traction reasons....you could set the code up for that as well. Use the NV ratio to determine what gear it's in, and then lookup the shiftlight threshold based on that. Just a simple "if NV > X then use A threshold, if NV < X use B threshold." If you like the same RPM all the time just use the same value for A and B.
Thread Starter
Supreme Member
Joined: Jan 2002
Posts: 1,162
Likes: 1
From: California
Car: Z28
Engine: L98
Transmission: T56
Originally posted by Craig Moates
I'd be interested to hear about your reverse lockout accomplishments as well when you get there.
By the way, how about RPM resolution up top for the 730? What if you wanted to shift at 7000?
I'd be interested to hear about your reverse lockout accomplishments as well when you get there.
By the way, how about RPM resolution up top for the 730? What if you wanted to shift at 7000?
Thread Starter
Supreme Member
Joined: Jan 2002
Posts: 1,162
Likes: 1
From: California
Car: Z28
Engine: L98
Transmission: T56
Originally posted by TheGreatJ
Reverse lockout should be easy enough. Just check current MPH against a max. value (say 5 or so) and enable reverse when below that threshold. That's how the 4th gens do it stock, IIRC. Finding a good place to put it in the current code will be harder than writing the algorythm, although it looks like you opened up plenty of space when you pulled the stock shiftlight stuff.
I had some ideas about the shiftlight too.....I know a few guys who like to shift 1-2 at a different RPM than the rest of the gears for traction reasons....you could set the code up for that as well. Use the NV ratio to determine what gear it's in, and then lookup the shiftlight threshold based on that. Just a simple "if NV > X then use A threshold, if NV < X use B threshold." If you like the same RPM all the time just use the same value for A and B.
Reverse lockout should be easy enough. Just check current MPH against a max. value (say 5 or so) and enable reverse when below that threshold. That's how the 4th gens do it stock, IIRC. Finding a good place to put it in the current code will be harder than writing the algorythm, although it looks like you opened up plenty of space when you pulled the stock shiftlight stuff.
I had some ideas about the shiftlight too.....I know a few guys who like to shift 1-2 at a different RPM than the rest of the gears for traction reasons....you could set the code up for that as well. Use the NV ratio to determine what gear it's in, and then lookup the shiftlight threshold based on that. Just a simple "if NV > X then use A threshold, if NV < X use B threshold." If you like the same RPM all the time just use the same value for A and B.
The multi-rpm shift light code would be pretty straightforward as you described. Heck, an adventerous person could set it up easily enough to have a different shift light rpm in every gear.
Trending Topics
Supreme Member
Joined: Aug 2001
Posts: 2,136
Likes: 2
From: Costal Alabama
Car: 1989 Iroc-Z
Engine: 350, ZZ4 equivalent
Transmission: Pro-Built Road Race 700R4
Axle/Gears: 3.23 Dana 44
I have wanted a shift light in my car for awhile even though it's automatic. I also think it would look nice to put LED's in the stock shift light location.
Will this work with the AUJP code?
Will this work with the AUJP code?
Senior Member
Joined: Jun 2000
Posts: 998
Likes: 0
From: Tuscaloosa, AL
Car: 91Z, 91RS, '84 Jimmy
Engine: L98, 355, L98
Transmission: 700R, T56, 700R4
The output wire that runs the factory shiftlight is used to control the torque converter clutch in an automatic car IIRC. You could write the code to operate the shiftlight on another ECM pin, but that would take more work, and a bit of research to find an appropriate output channel.
Thread Starter
Supreme Member
Joined: Jan 2002
Posts: 1,162
Likes: 1
From: California
Car: Z28
Engine: L98
Transmission: T56
Actually, according to the information I had (and my memory), they are on different pins.
I believe F1 is the shift light pin, and F(5? 6? 7? 8?) was the TCC pin.
I'll double check later when i get home.
I believe F1 is the shift light pin, and F(5? 6? 7? 8?) was the TCC pin.
I'll double check later when i get home.
Supreme Member
Joined: Aug 2001
Posts: 2,136
Likes: 2
From: Costal Alabama
Car: 1989 Iroc-Z
Engine: 350, ZZ4 equivalent
Transmission: Pro-Built Road Race 700R4
Axle/Gears: 3.23 Dana 44
The shift light pin is on pin GF1 and the TCC solenoid is on pin GF6. So the pins are not shared.
Joined: Apr 2004
Posts: 3,180
Likes: 3
From: Browns Town
Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
Might be able to use the PWM output from 3FCC
Chip "U2" pin 52 connects at 10-U20-11, ECM Pin "F5"
Write 7000 = OFF
Write D000 = 0% DC
Write DFFF = 100% DC
The output is shown as not used but keep reading.
That leaves all the other outputs alone so emmisions aren't sacrificed. makes agood candidate.
There may be a problem using that output in that I show it being used AS the CARS light already. not sure why that is.
Has anyone played with this on a bench to see if the output can be made to work on pin F5 ?
Everything I see at the moment indicates it should be there and not on F1.
Address $0196, bit 4 enables the PWM output.
3FCC sets the duty cycle.
How is F1 turned on? Its late and i'm just not seeing it.
I was thinking of doing a knock light from there but never got to it.
Allot of 730 guys have been looking for that to be implemented.
My original thought was to use the "knock" flag bit ($003A, b0)and the "no knock" ($003A, b1) bit to select the value that was loaded.
Chip "U2" pin 52 connects at 10-U20-11, ECM Pin "F5"
Write 7000 = OFF
Write D000 = 0% DC
Write DFFF = 100% DC
The output is shown as not used but keep reading.
That leaves all the other outputs alone so emmisions aren't sacrificed. makes agood candidate.
There may be a problem using that output in that I show it being used AS the CARS light already. not sure why that is.
Has anyone played with this on a bench to see if the output can be made to work on pin F5 ?
Everything I see at the moment indicates it should be there and not on F1.
Address $0196, bit 4 enables the PWM output.
3FCC sets the duty cycle.
How is F1 turned on? Its late and i'm just not seeing it.
I was thinking of doing a knock light from there but never got to it.
Allot of 730 guys have been looking for that to be implemented.
My original thought was to use the "knock" flag bit ($003A, b0)and the "no knock" ($003A, b1) bit to select the value that was loaded.
Last edited by JP86SS; Jun 27, 2005 at 01:17 AM.
Joined: Apr 2004
Posts: 3,180
Likes: 3
From: Browns Town
Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
Bit 7 (like it shows in your code)
Could've slapped me with trout on that one!
Could've slapped me with trout on that one!
Supreme Member
Joined: Sep 2003
Posts: 1,409
Likes: 1
From: Texas
I was going to get to this eventually, glad someone beat me to it.
$8D 7K stuff....
You have to use FDB L00B3 which = DRP
So you'll have to use LDD 00B3 etc
Or since the only time your interested is when
accB is < FF. Not sure it's accB, I think it might be inverted.
Can't remember right now. Swapping back to day shift so
I'm in a fog...
I believe there are spare non PWN pins available. F3 is one after a quick look.
To get the constant-
983040/DRP=RPM
Note DRP is inverse, so the lower the number, the higher the rpm and vice versa. Rbob posted similar in a few places, but if you're just a hair low on the knowledge curve you'll miss it. I did the first few times I read those posts.
You can stick L00B3 in your aldl and use the above constant in TP to log rpm >6375 too.
I haven't modded my bench yet to go there. But it looks fine when compared to RPM/25 with an occasional variance due to the different method of calculating the #.
The light code mod from above will work on AUJP too I'm pretty sure. Just not as posted.
You'll have to get JP86SS's hac and see what the offsets are between the various bins. While working on my WB patch I found AXXD, ANHT, AUJP are all a little bit offset from each other so you just have to figure out where the referenced code is and change it. Some of the values will be different from the listed code string due to AUJP being an AT bin. IIRC, the shift light is disabled in the code by have a temp? qualifier set to FF. JP might remember since he was the one who told me.
I don't think JP has posted this hac update yet...
$8D 7K stuff....
You have to use FDB L00B3 which = DRP
So you'll have to use LDD 00B3 etc
Or since the only time your interested is when
accB is < FF. Not sure it's accB, I think it might be inverted.
Can't remember right now. Swapping back to day shift so
I'm in a fog...
I believe there are spare non PWN pins available. F3 is one after a quick look.
To get the constant-
983040/DRP=RPM
Note DRP is inverse, so the lower the number, the higher the rpm and vice versa. Rbob posted similar in a few places, but if you're just a hair low on the knowledge curve you'll miss it. I did the first few times I read those posts.
You can stick L00B3 in your aldl and use the above constant in TP to log rpm >6375 too.
I haven't modded my bench yet to go there. But it looks fine when compared to RPM/25 with an occasional variance due to the different method of calculating the #.
The light code mod from above will work on AUJP too I'm pretty sure. Just not as posted.
You'll have to get JP86SS's hac and see what the offsets are between the various bins. While working on my WB patch I found AXXD, ANHT, AUJP are all a little bit offset from each other so you just have to figure out where the referenced code is and change it. Some of the values will be different from the listed code string due to AUJP being an AT bin. IIRC, the shift light is disabled in the code by have a temp? qualifier set to FF. JP might remember since he was the one who told me.
I don't think JP has posted this hac update yet...
Code:
;*********************************************************************************** ; ;This section info provided by Scott Lopez (Z69) and many thanks for the head start there :) ; ; AUJP 7730 OUTPUTS ; *************************************************************************** ; Terminal Chip pin # ECM Function $58 $60 ; Description & chip Conn version ; pin# pin # Specific ; PWM 3FD8 U2-3 10-U19-11 F1 Shift Light A/C N/A ; PWM 3FDA U2-2 14-U19-13 F2 EGR Port Sol WG ; Out 2 U2-49 6-U19-5 F3 Blank-Same as SES? Blank ; Port 24 U1-6 2-U19-3 F4 Air Divert TCC ; PWM 3FCC U2-52 10-U20-11 F5 Blank Blank N/A ; Out 3 U10-17 6-U20-5 F6 TCC Blank ; PWM 3FD4 U2-5 14-U18-13 F7 CCP Sol Blank N/A ; Port 41 U1-17 2-U20-3 F8 Blank-Same as MUXA? Blank ; 9-U21-1 E3 IAC A Hi ; Port 20 U1-10 9-U21-2 E4 IAC A Lo Same ; 9-U21-5 E5 IAC B Hi ; Port 21 U1-9 9-U21-4 E6 IAC B Lo ; SES U2-48 2-U18-3 E7 SES SES ; PWM 3FEA U2-51 9-U13-U10-25 E8 FAN1 CAC N/A ; PWM 3FD6 U1-4 10-U18-11 E9 EGR Sol EVRV N/A ; Out 1 U10-19 5-U16-2 A2 Relay 2-Same as TCC? Blank ; All values from code itself. ; 7000 = OFF ; D000 = O% DC ; D134 = 30% DC ; D200 = 50% DC ; DFFF = 100% DC ; $0066 Increments DC by 10% ;F1 Shift Light ;F2 EGR Port Sol ;F3 Blank-Same as SES? ;F4 Air Divert ;F5 Blank ;F6 TCC ;F7 CCP Sol ;F8 Blank Same as MUXA? ; ; ;E7 SES ;E8 FAN1 ;E9 EGR Sol ;A2 Relay 2 Same as TCC?
Last edited by Z69; Jun 29, 2005 at 04:33 AM.
Joined: Apr 2004
Posts: 3,180
Likes: 3
From: Browns Town
Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)
Engine: 406 Hyd Roller 236/242
Transmission: 700R4 HomeBrew, 2.4K stall
Axle/Gears: 3:73 Posi, 7.5 Soon to break
I've not posted the update yet, cause still trying to fill in some blanks. The list was provided by Z' and didn't want to put it out until I discussed it first. (but there it is.) 
Have found a bunch of the bits that control if the PWMs are enabled at the output pin but have a "bit" more to do in understanding the whole thing.
I've added control info at the end of the rows. (more to follow)
I am going to put up another thread concerning just the outputs and the sequence of events required to operate them.
So this was just a taste of being able to swap code without repinning, which WILL eventually happen
Jp
Have found a bunch of the bits that control if the PWMs are enabled at the output pin but have a "bit" more to do in understanding the whole thing.
Code:
AUJP 7730 OUTPUTS ; *************************************************************************** ; Terminal Chip pin # ECM Function $58 AUJP Address ; Description & chip Conn ; pin# pin # ; PWM 3FD8 U2-3 10-U19-11 F1 Shift Light A/C PWM 3FD8 0196, b2 enables ; PWM 3FDA U2-2 14-U19-13 F2 EGR Port Sol WG PWM 3FDA ; Out 2 U2-49 6-U19-5 F3 Blank-Same as SES? Blank ; Port 24 U1-6 2-U19-3 F4 Air Divert TCC 003F, b2, $60 = 0027, b7 ; PWM 3FCC U2-52 10-U20-11 F5 Blank Blank PWM 3FCC ; Out 3 U10-17 6-U20-5 F6 TCC Blank ; PWM 3FD4 U2-5 14-U18-13 F7 CCP Sol Blank PWM 3FD4 ; Port 41 U1-17 2-U20-3 F8 Blank-Same as MUXA? Blank ; 9-U21-1 E3 IAC A Hi 4002, b0 ; Port 20 U1-10 9-U21-2 E4 IAC A Lo Same 4002, b0 ; 9-U21-5 E5 IAC B Hi 4002, b1 ; Port 21 U1-9 9-U21-4 E6 IAC B Lo Same 4002, b1 ; SES U2-48 2-U18-3 E7 SES SES 3FFC, b3 0196, b4 enables ; PWM 3FEA U2-51 9-U13-U10-25 E8 FAN1 CAC PWM 3FEA, 0193, b2 enables ; PWM 3FD6 U1-4 10-U18-11 E9 EGR Sol EVRV PWM 3FD6 ; Out 1 U10-19 5-U16-2 A2 Relay 2-Same as TCC? Blank ; A/C Clutch Sol 3FFC, b2
I am going to put up another thread concerning just the outputs and the sequence of events required to operate them.
So this was just a taste of being able to swap code without repinning, which WILL eventually happen
Jp
Thread
Thread Starter
Forum
Replies
Last Post
