Chevy Impala SS Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
192 Posts
What year is your car?
Maybe someone can correct me on this, but the 91-96 B Bodys don't have any kind of computer in the trunk.
However there is a PCM under the hood, under the factory air box. A bad PCM will cause a no spark scenario, but it's unlikely that's the case.
 

·
Registered
Joined
·
3,859 Posts
What B Body has a Client Configuration Manager in the trunk? Sorry but that was the first result of my google search.

I have no clue what you are talking about.
 

·
Registered
Joined
·
192 Posts
What B Body has a Client Configuration Manager in the trunk? Sorry but that was the first result of my google search.

I have no clue what you are talking about.
I figured the op was talking about some kind of control module, PCM, BCM, TCM ect.
 

·
Registered
Joined
·
192 Posts
After a bit research, the CCM controls VATS.
 

·
Registered
Joined
·
500 Posts
From the FSM the Central Control Module (CCM) that's in the Fleetwood's controls the following functions:

Courtesy Lamp Control
Retained Accessory Power
Variable Effort Steering
Illuminated Entry
Delayed Interior Lamps
Daytime Running Lamps
Security System
Twilight Sentinel

The security system (VATS) could prevent the car from starting, but I was under the impression it disables the fuel system somewhere and not the ignition, so if you definitely don't have spark I wouldn't suspect that problem. Also the security light on the dash should be on or blinking or something if the VATS is acting up.
 

·
Registered
Joined
·
3,859 Posts
Ah, classic example of asking a question without providing all the details. I know nothing about the Cadillac


No spark is usually a problem in the ignition system itself. Coil, ICM, etc.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #10
I asked the question because im seeing if it could be the computers going bad, i did replace the optispark/harness,coil, ignition control module also checked all fused and tryed to switch out pcm`s and still no spark
 

·
Registered
Joined
·
192 Posts
Are all connections secure? A big problem on these cars is wiring and broken connectors.
 

·
Registered
Joined
·
500 Posts
If you have a decent multimeter, (one that can read frequency) there's a good thread somewhere on here that details how to check if the opti is sending a signal to the pcm. Since it also doubles as a cam position sensor, might be worth looking into. And as crazy as it sounds, it could be the opti. I'm not aware of any current aftermarket ones that are reliable, and it's totally plausible that you could have one that's doa.

Oh, and if you do try a different pcm, make sure it's also from a 96 Fleetwood. An earlier one would probably plug in but I doubt it would work, and given the additional electronics in the Cadillac, I doubt one from a b-body would fire the car either.
 

·
Registered
Joined
·
1,874 Posts
If you get a 96 pcm from a 96 Caprice Roadmaster or Fleetwood with the same gears as your car:
1. the Traction Control will probably only work if the pcm is from a Fleetwood (because traction control is usually disabled in B-car .bin files but enabled in D-car calibrations)
2. everything else should be ok.

If you get a 96 pcm from a 96 Caprice Roadmaster or Fleetwood with different gears:
1. don't think Traction Control will work regardless (hope I'm wrong and it works …)
2. speedo will probably read wrong (hope I'm wrong and it reads correctly …)
3. everything else should be ok, but try not to do this.

If you get a 95 pcm from a 95 Caprice Roadmaster or Fleetwood with the same gears:
1. your knock sensors will not work
2. the Traction Control will probably only work if the pcm is from a Fleetwood
3. besides the obvious knock sensor codes, other hidden codes will also be thrown which may affect performance
4. if this is an emissions legal option, either change the knock sensors in the block to OBD1 (might as well tune so as not to waste money), or modify your pcm to accept OBD2 knock sensor frequencies.
If not, get a 96 pcm.

If you get a 95 pcm from a 95 Caprice Roadmaster or Fleetwood with different gears
1. your knock sensors will not work
2. don't think Traction Control will work regardless
3. speedo will probably read wrong
4. besides the obvious knock sensor codes, other hidden codes will also be thrown which may affect performance
5. if this is not an emissions legal option for you, get a 96 pcm.

If you get a 94 pcm, see the appropriate 95 pcm admonition above, plus your transmission will lock its TCC differently.

2.56 (GM8)
2.93 (GW9)
3.42 (GU6) (possible but very unlikely)
 

·
Registered
Joined
·
60 Posts
Discussion Starter #15
Thanks for the info
If you have a decent multimeter, (one that can read frequency) there's a good thread somewhere on here that details how to check if the opti is sending a signal to the pcm. Since it also doubles as a cam position sensor, might be worth looking into. And as crazy as it sounds, it could be the opti. I'm not aware of any current aftermarket ones that are reliable, and it's totally plausible that you could have one that's doa.

Oh, and if you do try a different pcm, make sure it's also from a 96 Fleetwood. An earlier one would probably plug in but I doubt it would work, and given the additional electronics in the Cadillac, I doubt one from a b-body would fire the car either.
Yes i thought about the opti being bad out the box but it was doing this even before i changed the opti so thats why i changed it so makes me believe its something else and i did get the pcm from same year and Model
 

·
Registered
Joined
·
60 Posts
Discussion Starter #16
If you get a 96 pcm from a 96 Caprice Roadmaster or Fleetwood with the same gears as your car:
1. the Traction Control will probably only work if the pcm is from a Fleetwood (because traction control is usually disabled in B-car .bin files but enabled in D-car calibrations)
2. everything else should be ok.

If you get a 96 pcm from a 96 Caprice Roadmaster or Fleetwood with different gears:
1. don't think Traction Control will work regardless (hope I'm wrong and it works …)
2. speedo will probably read wrong (hope I'm wrong and it reads correctly …)
3. everything else should be ok, but try not to do this.

If you get a 95 pcm from a 95 Caprice Roadmaster or Fleetwood with the same gears:
1. your knock sensors will not work
2. the Traction Control will probably only work if the pcm is from a Fleetwood
3. besides the obvious knock sensor codes, other hidden codes will also be thrown which may affect performance
4. if this is an emissions legal option, either change the knock sensors in the block to OBD1 (might as well tune so as not to waste money), or modify your pcm to accept OBD2 knock sensor frequencies.
If not, get a 96 pcm.

If you get a 95 pcm from a 95 Caprice Roadmaster or Fleetwood with different gears
1. your knock sensors will not work
2. don't think Traction Control will work regardless
3. speedo will probably read wrong
4. besides the obvious knock sensor codes, other hidden codes will also be thrown which may affect performance
5. if this is not an emissions legal option for you, get a 96 pcm.

If you get a 94 pcm, see the appropriate 95 pcm admonition above, plus your transmission will lock its TCC differently.

2.56 (GM8)
2.93 (GW9)
3.42 (GU6) (possible but very unlikely)
Thanks for the info but i did get the same year pcm and model
 
1 - 17 of 17 Posts
Top