What if, Black Box PCM repurposed as TCM?

[dave w]

I'm in the planning stages of a daily driver 1996 S10 Blazer L33 engine swap.

The challenges:
Retain the original VCM due to ABS and other related chassis interactions with the VCM. Quote from:http://www.currentperformance.com/s1...custom-wiring/ "The ’96 model has an ABS control under the hood that is only used in ’96. This system is controlled by the stock truck computer and the wiring runs through the engine harness, whereas most other years have a separate computer and harness to control the ABS.

I've confirmed there is wiring (undocumented in All Data Online) from the 96 VCM to the ABS module. I figured if I have to keep the original VCM, I'd like to keep as much VCM wiring as possible, including the 4L60E transmission wiring. I'd like to keep the L33 PCM wiring to a minimum (bare bones). Washington State emission testing for the 1996 Blazer is read for OBD2 codes only.

The list of inputs I think are needed for the original VCM to operate the 4L60E:
VSS
Ignition Power
Ground
Battery
TPS (will be another challenge due to the L33 Drive by Wire system)
Brake Input
Ignition RPM Input???? (if required what RPM signal from the L33 PCM would be used?)
Custom Flash

Ideas and thoughts are welcomed

dave w

[Skinny Pedal]

Convert the L33 to DBC for TPS. Its still 24x. Convert to single wire P/N for idle/spark control.

With RPM is it hitting the black box from crank sensor? Set tach out to proper pulse and maybe use a pull up circuit. Or am I thinking about it wrong?

Other question is what is hitting the ABS from VCM? Speed and what, I think it shares a brake signal. I do not believe there are any comms. If thats the case then run the LS1B and ditch the VCM. On LS conversions we have done with that era of truck we have always only used the ECM from the LS. Never had an issue.

As far as code reading. There are only codes if you tie the comms together. Get what I mean.

[Montecarlodrag]

Last time I checked the wiring for a blazer this year, I had the impression the ABS module is only a modulator valve, is not a ABS module per se. So it needs the stock PCM to operate.
The only blazer from this year I have done a 5.3L swap to already had the ABS deleted so I didn't try to make it work.
What I would do is to use a EBCM from a newer truck and delete the harness and stock PCM to use the L33 PCM and harness. The use the same signals so it should be easier than making 2 PCMs live together

[Skinny Pedal]

With his year L33 the EBCM would need the BCM too, right? On DBW truck/suv doesnt gen 3 route TAC control/external control and can comms through the BCM. I could be on crack here. Just trying to think what all we have kept on full chassis swaps. For some reason the BCM is sticking in my mind for proper operation of EBCM.

[LRT]

What I would do is to use a EBCM from a newer truck and delete the harness and stock PCM to use the L33 PCM and harness. The use the same signals so it should be easier than making 2 PCMs live together

+1

Swap in a 1998+ S10 ABS Pump and Module (EBCM) assembly (they are very inexpensive used - eBay or wrecking yard). A P01 or P59 PCM is capable of sending a 4K VSS signal to the speedometer, and a 128K VSS signal to the EBCM.

[Montecarlodrag]

With his year L33 the EBCM would need the BCM too, right? On DBW truck/suv doesnt gen 3 route TAC control/external control and can comms through the BCM. I could be on crack here. Just trying to think what all we have kept on full chassis swaps. For some reason the BCM is sticking in my mind for proper operation of EBCM.

Well, He didn't say which year is the L33 computer. If it's Gen4 with CAN bus it will be much more difficult.
For Gen3 controllers there is no need for a BCM. TAC module, ABS and everything work without a BCM since the Class2 bus comes from the PCM to all other modules.
Gen4 controllers use the BCM as a bridge for Class2, but the EBCM is tied to the high speed GMLAN, the problem is not the BCM but the added complexity. I have not tried this but have done similar things and I can say Gen4 electronic systems are a PITA, a lot more work and time for little to no advantage using them.

I think there are no Gen4 L33 engines, so I should be a Gen3

[Skinny Pedal]

I just meant with 1 meg gen 3 truck/suv there are further tac and EBCM control in the BCM. Its not needed for full stand alone.

[dave w]

I've only seen pictures of the engine and harness. The smart phone pictures are poor quality. It appears the harness is from a LS1b PCM (green / blue). The only clear picture I have shows the ECM / PCM connectors cut from the harness. The original PCM is not available, who knows where it is. The engine has seen several owners recently. My job, is to build a custom harness and flash a PCM. I find it very interesting that Current Performance builds a harness for the same vehicle application that requires two computers, so monkey see / monkey do?
Actually this is whole project is a nightmare in the making!

I'm challenged by the option of the DBC option, seems like a good plan would be to use a native PCM / Flash for the L33.

Would the L33 PCM correctly operate (plug-n-play) the 1996 4L60E?

dave w

[Skinny Pedal]

I think 96 is the year you have to change internal electronics... Upgrade.

L33 is a 2005-2007 engine from 1/2 ton silverado and sierra. Should be 1 meg gen 3 all the way. Converting is not hard and can stay 1 meg. Now I only say convert to ease integration of systems if you go that route. TPS and APP DBW signals are not going to like a piggy back. Plus voltage is not in the same line as normal TPS.

[lionelhutz]

The PCM should control the transmission just fine. it was the 95 that was a 1-year only. As you go newer there are upgraded internals and the bellhousing is removable starting in 97 or 98, but they can all swap up until the ISS was added around 2008 I believe for use with TCM's. Just the converter changes to match with the LS crank dimension.

I'd ditch the original box. Either remove that early ABS system or upgrade it to a newer system.

[Skinny Pedal]

I can never remember the odd ball 1 year minus one solenoid 4l60. LOL

[JeepsAndGuns]

+1

Swap in a 1998+ S10 ABS Pump and Module (EBCM) assembly (they are very inexpensive used - eBay or wrecking yard). A P01 or P59 PCM is capable of sending a 4K VSS signal to the speedometer, and a 128K VSS signal to the EBCM.

I really have nothing useful to input to the thread, just reading through it to have something to do.
But I agree with LRT. If the vcm/abs is a one year odd ball thing, then why keep it? If it fails in the future, parts or replacements may be very hard to find and expensive. I would think that swapping to a more common and/or compatible abs module might be the better road to travel on?

[Montecarlodrag]

Truth is, GM is very friendly for engine swaps and part interchangeability. I have done swaps in 88 trucks keeping stock cluster fully functional including speedo, controlled by a 2003-2007 P59 PCM.
Ford and Dodge are much more difficult.

[dave w]

I saw the engine that will be going into the 96 Blazer, see attached pics.

Would I be correct, this is a 58x engine (CKP sensor is gray)?

Would I be correct, the original ECM for this engine was the E38?

Would I be correct, this is a 2007 pickup engine?

Would I be correct, I will need to use a Lingenfelter 58x to 24x converter (http://www.lingenfelter.com/mm5/merc...3#.VoYMZE_LLuc) to use an '0411 PCM?

Would I be correct, converting to Drive by Cable is a good plan?

Would I be correct, this will be a nightmare conversion (not budget friendly) regardless the option of one computer or two computers is used?

Thoughts are appreciated,

dave w

[mecanicman]

I saw the engine that will be going into the 96 Blazer, see attached pics.

Would I be correct, this is a 58x engine (CKP sensor is gray)?
Yes
Would I be correct, the original ECM for this engine was the E38?
Yes
Would I be correct, this is a 2007 pickup engine?
Yes
Would I be correct, I will need to use a Lingenfelter 58x to 24x converter (http://www.lingenfelter.com/mm5/merc...3#.VoYMZE_LLuc) to use an '0411 PCM?
Yes, or replace reluctor and cam timing gear.
Would I be correct, converting to Drive by Cable is a good plan?
Yes, although dbw can be done.
Would I be correct, this will be a nightmare conversion (not budget friendly) regardless the option of one computer or two computers is used?
No, can be done very budget friendly( although I guess that depends on what your budget is?)
Thoughts are appreciated,

dave w

Keeping the original pcm is not feasible. Either disable the abs and run conventional brakes or swap to a newer abs module.