CASE Relearn

[Fratsit]

I installed a cam back in September and upgraded to a 02 OS system a few months back. While browsing the forum here and at LS1tech I was reading about a CASE relearn.

My question is with the new cam and upgraded OS would a crank position sensor relearn be the smart thing to do?

I eventually plan to run my RR full time in the car, but for now I am still using the stock PCM.

R/

Frat

[Happy Jim]

You shouldn't need to do the CASE even after a full flash as all the cal details are retained. I am no expert but if you needed to re-learn I think you'd know by now (presumably the car would either not run, or run like a bag of spanners if it needed doing).

Rgds

Jim

[joecar]

A CASE relearn is needed if:
- crank sensor is replaced,
- PCM is replaced,
- stall converter is installed (change of "rotational mass").

Otherwise as Jim stated, the PCM stores CASE info in non-volatile memory which is not altered by reflashing.

[Fratsit]

Thanks for the feedback, guys. I appreciate it.

By the way.... whats a "bag of spanners"? :)

Thanks again.

R/

Frat

[Joel_SS]

A CASE relearn is needed if:
- crank sensor is replaced,
- PCM is replaced,
- stall converter is installed (change of "rotational mass").

Otherwise as Jim stated, the PCM stores CASE info in non-volatile memory which is not altered by reflashing.


Joe, you mention a stall being added.. You think not doing this could casue idle problems? I have some idling gremlins I cannot get out and I have a 4k stall and a CASE has never been prefomred that I am aware of..

[joecar]

Joel,

From what I've previously read from GM drivability class material, it seems that the PCM uses CASE info in it's misfire detection algorithm (PCM uses crank sensor position error limits to analyze the rate of change of crank motion, and if it's outside computed "envelope", then it flags a misfire...)...

The engine's rotating mass "moment of inertia" (which includes the TC) has a direct influence on the rate of change of crank motion...

How this relates to idle: I don't know what the PCM does if it detects misfires at idle... :nixweiss: ...I have no idea. :bash:

How this relates to TCC lockup: the PCM momentarily unlocks the TCC when misfires are detected.

So, for the TCC, it would be a good idea to do a CASE relearn anyway. ;)

Joe

[Happy Jim]

By the way.... whats a "bag of spanners"? :)
Frat

What my car sounds like after I've been tinkering with it :muahaha:

[Fratsit]

:eek:


:cheers:

Frat

[joecar]

spanner (UK) == wrench (US)

[Biggsy]

spanner (AUS) == loser/idiot (world):)


A CASE relearn is needed if:

- stall converter is installed (change of "rotational mass").

OK, did not know that. I changed my torque converter to a 3000rpm stall a few months back. Its physically smaller/lighter than the original one. So you're saying I should do a CASE relearn?

I haven't noticed any difference since the install (except severe lack of traction to the road! :D )

What problems should/could happen?

Dave.

[joecar]

Dave,

CASE info has to do mainly with misfire detection;

if you're not having problems due to misfires (mainly TCC repeatedly unlocking momentarily) then you should be fine without doing it;

some people do it, some don't.

Joe

[Biggsy]

No problems, it aint broke so I wont fix!

Thanx Joe:cheers:

Dave.

[joecar]

No problems, it aint broke so I wont fix!

Thanx Joe:cheers:

Dave.Yeah... lol, generally speaking, I learnt that lesson the long hard way, mate... :cheers:

[Fratsit]

No problems, it aint broke so I wont fix!

Thanx Joe:cheers:

Dave.

Yeah...don't be a Spanner :D

...sorry...had to do it. :)

R/

Frat

[joecar]

lol.

[TAQuickness]

IF there is any doubt, performing a case relearn wouldn't hurt. only takes about 15-30 seconds to perform as well.

[Biggsy]

Yeah...don't be a Spanner :D

...sorry...had to do it. :)

R/

Frat
:moon1: ;)

[Fratsit]

:cheers: