1997 F-Body ECM

[Terminal_Crazy]

The spark retard request isn't done over serial data, it's done via a "dumb" signal on pin A23. You just pull it high (connect to 12V). So if you engineer a way to connect pin A23 to +12V at will, there's your ASR spark retard.

Excellent. Thanks for that.

Mitch

[NomakeWan]

The spark retard request isn't done over serial data, it's done via a "dumb" signal on pin A23. You just pull it high (connect to 12V). So if you engineer a way to connect pin A23 to +12V at will, there's your ASR spark retard.

Excellent. Thanks for that.

Mitch

Okay so, I had a look at some pin diagrams from my FSM, as well as the ABS/ASR manual for 1995. There's some interesting discrepancies.

Regarding the ASR Spark Retard, the 1995 F-Body pinout posted earlier in this thread claims it's on A23. Both my 95 Y-Body FSM and my 94 Y-Body FSM say it's on C12, as Tom H stated a few posts ago. Sadly while my 1992 ABS/ASR manual lists ECM-side pinouts (useless since 1992 was a totally different computer), my 1995 ABS/ASR manual does not list pinouts as it was a generic manual for B/E/K/Y cars, so it only lists the EBTCM pinouts and not the PCM-side pins they connect to. So I couldn't confirm that way. But two FSMs say that it's C12, and Tom says it's C12, so I'm inclined to believe that it is, in fact, C12. Which would leave me to wonder what the heck A23 is.

Additionally, as a side note, the pinout that was posted earlier in the thread claimed that pin B22 is "TCC TEMPERATURE SWITCH," Circuit 585, Tan/White wire. But my Y-body FSMs claim that B22 is "CRUISE ACTIVE SIGNAL," Circuit 396, Lt Blue/Black wire. This appears to be the only actual discrepancy between wires I've seen. While I could chalk this up to F-body vs Y-body, that's a pretty massive difference in function, and one that as far as I'm aware has not been documented.

[sherlock9c1]

But my Y-body FSMs claim that B22 is "CRUISE ACTIVE SIGNAL," Circuit 396, Lt Blue/Black wire.

Hopefully without taking this thread more than a few posts sideways, what does the PCM do in response to "cruise active"? Does it change auto transmission shift behavior?

[Terminal_Crazy]

On My PCM Connerction Printout which seems to match my '95 Z28 with 16188051 PCM - (It's not 100% reliable as it was probably off a 95 corvette )


C12 is listed as NOT Used
A23 Orange/Black circuit 463 is listed as Traction Control Spark Retard Request

Probably depends on year or PCM


Thanks
Mitch

[Tom H]

Okay so, I had a look at some pin diagrams from my FSM, as well as the ABS/ASR manual for 1995. There's some interesting discrepancies.

Regarding the ASR Spark Retard, the 1995 F-Body pinout posted earlier in this thread claims it's on A23. Both my 95 Y-Body FSM and my 94 Y-Body FSM say it's on C12, as Tom H stated a few posts ago. Sadly while my 1992 ABS/ASR manual lists ECM-side pinouts (useless since 1992 was a totally different computer), my 1995 ABS/ASR manual does not list pinouts as it was a generic manual for B/E/K/Y cars, so it only lists the EBTCM pinouts and not the PCM-side pins they connect to. So I couldn't confirm that way. But two FSMs say that it's C12, and Tom says it's C12, so I'm inclined to believe that it is, in fact, C12. Which would leave me to wonder what the heck A23 is.

Additionally, as a side note, the pinout that was posted earlier in the thread claimed that pin B22 is "TCC TEMPERATURE SWITCH," Circuit 585, Tan/White wire. But my Y-body FSMs claim that B22 is "CRUISE ACTIVE SIGNAL," Circuit 396, Lt Blue/Black wire. This appears to be the only actual discrepancy between wires I've seen. While I could chalk this up to F-body vs Y-body, that's a pretty massive difference in function, and one that as far as I'm aware has not been documented.

Ignore my earlier message, looks to need a bit more study. -Tom