Anyone got any insight on PCM replacement on GM's? ('01 Cavalier)

[5150MyU]

My above P0440 post is for your vehicle.

Before programming

IMPORTANT: Do NOT program an existing control module with the identical software/calibration package. This procedure is not a short cut to correct a driveability condition. This is an ineffective repair. A control module should only be programmed when the following occurs:

• When a service procedure instructs you to replace the control module. The service part control module does not contain operating software or calibrations.
• General Motors Corporation releases an updated software/calibration package.

Ensure the following conditions are met before programming a control module:

• Vehicle system voltage:
• There is no charging system concern. All charging system concerns must be repaired before programming a control module.
• Battery voltage is greater than 12 volts but less than 16 volts . The battery must be charged before programming the control module if the battery voltage is low.
• A battery charger is NOT connected to the vehicle's battery. Incorrect system voltage or voltage fluctuations from a battery charger, may cause programming failure or control module damage.
• Turn OFF or disable any system that may put a load on the vehicle's battery.
• Daytime Running Lights (DRL) . Applying the parking brake, on most vehicles, disables the DRL system.
• HVAC systems
• Engine cooling fans, etc.
• The ignition switch is in the proper position. The scan tool prompts you to turn ON the ignition, with the engine OFF. Do NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
• All tool connections are secure:
• RS-232
• The connection at the DLC is secure.
• Voltage supply circuits
• DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.
• If you are performing the pass-through programming procedure using a notebook computer without the power cord, ensure the internal battery is fully charged.

After programming
The powertrain may operate slightly different after a control module software/calibration update. Operating the powertrain through various driving conditions allows the control module to re-learn certain values. The control module must re-learn the following after a software/calibration update:

• Fuel trim correction
• Idle air control learned position
• Automatic transmission shift adapts

Other learned values only re-learn by doing a service procedure.

If a control module is replaced the following service procedures must be performed:

• The Crankshaft Variation Learn Procedure, if applicable.
• The Engine Oil Life Reset Procedure, if applicable.
• The Idle Learn Procedure, if applicable.
• The Inspection/Maintenance Complete System Set Procedure
• The Vehicle Theft Deterrent Password Learn Procedure, if applicable.
• The TP sensor Learn Procedure, if applicable.

Also

IMPORTANT: A Crankshaft Position (CKP) system variation learn procedure must be performed any time a change is made to the crankshaft sensor to crankshaft relationship. Changing the crank sensor to crankshaft relationship will not allow the Powertrain Control Module (PCM) to detect misfire at all speeds and loads accurately, resulting in a possible false misfire Diagnostic Trouble Code (DTC) being set.

Removing a part for inspection and then reinstalling the same part is considered a disturbance. A false DTC P0300 could be set if the CKP position variation learn procedure is not performed.

The learn procedure is required after the following service procedures have been performed, regardless of whether or not DTC P1336 is set:

• PCM replacement
• Engine replacement
• Crankshaft replacement
• Crankshaft position sensor replacement
• Any engine repairs which disturbs the crankshaft/harmonic balancer to the crankshaft position sensor relationship

A fully warmed-up engine is critical to learning the variation correctly. If a valid learn occurs, no other learns can be completed on that ignition cycle.

If the engine cuts out before the specified learn procedure engine speed or at normal fuel cut-off RPM, the PCM is not in the learn procedure mode. Review the crankshaft position system variation learn procedure and re-enable the learn procedure. Verify that the scan tool displays Test in Progress.

CAUTION: Before performing the Crankshaft Position System Variation Learning Procedure always set the vehicle parking brake and block the drive wheels in order to prevent personal injury. Release the throttle immediately when the engine starts to decelerate in order to eliminate over revving the engine. Once the learn procedure is completed, the control module will return engine control to the operator and the engine will respond to the throttle position .

IMPORTANT: The battery must be fully charged and in good condition. The scan tool connection at the data link connector (DLC) is clean and tight before starting the crankshaft position system variation learn procedure.

1. Close the hood.
2. Block the drive wheels and set the vehicle parking brake.
3. Put the vehicle in Park or Neutral.
4. Turn all the accessories OFF.
5. Install a scan tool.
6. Start and run the engine until it is at the normal operating temperature of 74°C (165°F) .
7. With the engine still running, enable the crankshaft position system variation learn procedure with the scan tool.
8. Press and hold the brake pedal firmly. Accelerate to wide-open throttle (WOT). Release the throttle when fuel cut-off is achieved.
9. Verify with the scan tool that the crankshaft variation has been learned.

A fully warmed up engine is critical to learning the variation correctly. If a valid learn occurs, no other learns can be completed on that ignition cycle.

If the engine cuts out before the specified learn procedure engine speed or at normal fuel cut-off RPM, the PCM is not in the learn procedure mode. Review the crankshaft position system variation learn procedure and re-enable the learn procedure. Verify that the scan tool displays Test in Progress.

If the variation will not learn, perform this procedure up to 10 times.

 

[phucheneh]

Wait-a-minute-now-here...

IMPORTANT: Do NOT program an existing control module with the identical software/calibration package. This procedure is not a short cut to correct a driveability condition. This is an ineffective repair. A control module should only be programmed when the following occurs:

When a service procedure instructs you to replace the control module. The service part control module does not contain operating software or calibrations.

General Motors Corporation releases an updated software/calibration package.

...if I pull a used PCM from the same year/engine/trans...it will have software on it. Does this mean it DOESN'T need to be programmed with the vehicle information (i.e. VIN) to work?

 

[5150MyU]

Doubt it will like having the PCM and BCM not jive, but I really don't know.

 

[phucheneh]

Also, I meant to describe some starkly different experiences with the two most local Chevy dealers...

Called Bob Freeland Chevy:

Got told they would not work off of someone else's diagnosis. 'I know this,' I say. When I worked at the dealer, I wouldn't either. But I wouldn't turn down a ticket that said 'Customer requests install provided PCM and program to vehicle.' Simply wording something right absolves you of liability, should the repair not work. Two different people do not understand this. Furthermore, I ask them what happens if I send them the car for diag, they replace the purge solenoid, and it still doesn't work...do I get a free PCM? 'Well, no...' and then the clincher...'but it's not the PCM anyway, those don't go bad.'

'Thanks for your time, I will be sure to steer business away from you at every opportunity, as you are obviously incompetent and/or thieves.' *click*

Carl Black Chevy:

'Yeah, we could do that for you. 1.5 hours labor to install and program.'

My jaw about hits the floor because that was so easy and reasonable. The guy even knows that they need to word it a certain way on the repair order. 'So you're familiar with C-Y-A,' I say. 'Yup,' is his mildly amused response. He even readily admits that bad PCM's are very common on these vehicles.

...yeah, if anyone is ever in Nashville and needs a Chevy dealer: Carl Black. I wouldn't take the time to shit on Bob Freeland.

 

[phucheneh]

Doubt it will like having the PCM and BCM not jive, but I really don't know.

What's your experience? Do you just have access to the GM technical info, or are you an active GM tech? Just curious.

This might just be one of those 'won't know it until you try it' type of things.

Does an '01 Cavalier HAVE a BCM or use CAN? I honestly don't know. It looks like the engine and trans computer are one and the same, so I'm wondering if that's not the only module in the car; with the interior stuff (chimes and shit) being managed by the radio (I think?), like on slightly older cars.

 

[5150MyU]

Non active
Mopar 8 years.
GM 4 years.
Independant 8+ years.
As for the BCM and CAN I'll have to look.

 

[phucheneh]

Don't go out of your way or anything, I'm just curious. But my experience has been that when the ECM (plus TCM, if applicable) is the only main 'computer' on the car...i.e. no CAN bus network with a BCM (or REM; essentially a rear BCM, admist often multiple other computers)...the engine computers can often be 'hot-swapped' (as much as that term could apply to cars) without requiring programming.

 

[phucheneh]

Mild necro-bump for an LOL:

This car has been sllllooowww goings. After they finally came up with the cash to replace the ECM (it did require programming; tried a swap and it trips the immobilizer), I checked the monitors for them multiple times. Evap would never ready itself. Damn near forgot about it, until last week they finally said the CEL came back. I cursed. A lot.

...I get over to look at it and check codes...P0440 again. Balls. Then they decide to tell me- oh yeah, I left the gas cap loose. And sure enough, that sets P0440. I think GM basically just ignored all the other evap codes when they made this car. Or they're all checked after P0440, which would have already failed for just about any evap problem.

But yeah, it didn't decide to run the test until they happened to leave the cap loose. Sweet.

So I have to clear it, and decide to just go drive the thing around to get all the monitors set myself. Fuck this car sucks. It sets some monitors nearly instantly and never runs the others. I use google to try and find the conditions for running the evap monitor...

...and get this thread. Where the technical info about P0440 was initially relatively useless. Now it tells me why the damn monitor won't set. Heh. The specifics of the required cold start are absurdly specific. Hell, in some regions, you could go six months without the ECM running this test.

It's sorted out now. This also helped:

http://productforum.autorepairdata.com/forum/showthread.php?t=2913