In th is specia l ed i t ion of TechTips, we wil l address some of thequestions that technicians ask mostfrequently regarding computer relearnprocedures when they insta l l ourremanufactured computers. We havealso included a section addressingquestions regarding the BDM scantool and Iflash software

GENERAL MOTORSVEHICLE COMPUTERRELEARN PROCEDURES

Performing any of the followingrepairs may require you to initiate acomputer relearn procedure in orderto restore proper vehicle operation.

• Powertrain Control Computer replacement wi th a non-transferable PROM

• Powertrain Control Computer reprogramming

• Body Control Computer• Instrument Cluster replacement• Engine replacement• Crankshaft replacement• Crankshaft harmonic balancer

replacement• Crankshaf t pos i t ion sensor

replacement• Diesel Engine controller• Diesel engine PCM wi th or

wi thout in jec t ion pump replacement

• Diesel engine f ront cover replacement

Here a re some he lp fu l t ips toper form the sys tem re learn ,depending upon the particular repairthat you have performed.

Powertrain Control ComputerReplacement with a non-transferable PROM

Al l computers be ing rep lacedmust be reprogrammed or“ re f l ashed” . Th is i s so thereplacement computer has the mostup- to-da te in format ion for tha tparticular vehicle. This information isspecific for the vehicle based on thevehicle identif ication number, andcannot be used on another vehicle,even though they may appear to besimilar. Relearn procedures involve:Crankshaft Variation (CASE Learn),Engine Idle speed, Theft Deterrentpassword, and Transmission adaptiveshift points.

Powertrain Control ComputerReprogramming

I f d iagnost ics revea l tha t areprogram or re - f l ash o f thecomputer i s necessary , re learnprocedures invo lve : Crankshaf tVariation (CASE Learn), Engine Idlespeed, Theft Deterrent password, andTransmission adaptive shift points.

Body Control Computer &/orInstrument Clusterreplacement

Theft deterrent password relearnis necessary.

Engine, crankshaft, harmonicbalancer, and crankshaftposition sensor

I f any o f the above i t ems arereplaced, then a Crankshaft Variationrelearn is necessary.

RELEARN PROCEDURES

IMPORTANT: Please note that theTheft Deterrent Password Relearnmust be performed first, otherwisethe vehicle may not start.

THEFT DETERRENTPASSWORD RELEARN

General Motors uses threedifferent types of vehicle theftdeterrent systems in their cars andtrucks manufactured from 1986. They are:1. Pass-key or Passkey 2 (PK2)2. Passlock 3. Passkey 3 (PK3) or Passkey 3+

Instead of listing all of the vehiclesand the systems that they use, wewi l l s impl i fy the ident i f ica t ionprocess by tak ing a look a t thevehicle ignition key (Refer to page 8for key identification). There is oneother system, referred to as VATS(Vehicle Anti-theft System) that isused by GM. This system is similarto Passkey, but since a relearn isnot necessary, we will not elaborateon this system in this article. Byreferring to the chart and matchingthe cor rec t key, you can sa fe lyidentify the system that the vehicleuses, and, in turn, determine thecorrec t re learn procedure. Justremember, that this article pertainsonly to those vehic les wi th a re-programmable or “re-flashable”PCM.

Fall 2003

Standard Motor Products, Inc. Long Island City, NY 11101

ENGINE CONTROLS AND FUEL SYSTEMS

PASSKEY & PASSKEY 2

Th is sys tem cons is ts o f : thePowertrain Control Module (ECM orPCM), Body Control Module (BCM) orPasskey theft deterrent module, andthe ignition lock and key. In mostcases, the theft deterrent duties arehandled by a Passkey module. Inthose vehicles, if you are replacing akey, al l you must do is match theresistance of the existing key that isin use . I f you rep lace the the f tdeterrent module, then the modulewill learn the existing key resistancewith the first start up sequence. Attha t po in t , the res is tance i spermanent ly memor i zed by themodule , and can no longer bechanged. No relearn is necessary. Inthis situation, the vehicle will startand run wi th no prob lem. I f thevehicle won’t start, check your scantoo l fo r a VTD (Veh ic le The f tDeterrent) Fail-Enable Mode troublecode, or if the security light on thedash is illuminated. If you have thiscode, then the vehicle probably isequipped with a BCM, and you mustperform a relearn.

The next section applies only tothose vehicles that use a BCM.Forthose vehicles that use a BCM, theBCM can learn the resistance value ofthe existing key by using the relearnprocess.

In order for the vehicle to start,the BCM (as wel l as the Passkeymodule in o ther veh ic les) mustidentify the resistor pellet in the key,then the BCM sends a password tothe PCM. If this password matchesthe password stored in the PCM, thesystem enables fuel delivery. So youcan see that if either the BCM or PCMare replaced, a relearn procedure isnecessary . Th is same re learnprocedure can be used if an ignitionkey with a different resistance valueis used to replace the existing key.

Be fore beg inn ing the re learn ,make sure there is a fully charged

battery in the vehicle, and both theBCM and PCM are properly poweredup and in communication with eachother. Now you’re ready to initiate therelearn procedure. 1. First, insert the ignition key and

turn the ignit ion switch to the “On” position (Do not start the engine). Leave the switch on for 11 minutes. The security l ight may flash or be on steady during this 11 minute period. Make sure the l igh t is no longer on or flashing before proceeding to #2 .

2. Turn the ignition switch off for 30 seconds.

3. Turn the ignition switch to the “On” position (as in step #1) for 11 minutes again.

4. Turn the ignition switch off for another 30 seconds.

5. Turn the ignition switch to the “On” position for 11 minutes a third time.

6. Turn the ignition switch off for 30 seconds one final time.

7. Turn the ignition switch to the “On” position one final time and wait 30 seconds.

8. Attempt to start the engine.I f the engine s tar ts and runs normal ly , the re learn is complete. If the engine does not start, check

for trouble codes and address thembefore a t tempt ing the re learnprocedure again.

PASSLOCK

The Passlock system is designedto prevent vehicle operation if the keyis not used to start the vehicle. Thekey , wh ich does not conta in aresistor will turn the Passlock lockcylinder. The Passlock lock cylinderwill relay a resistance code to theinstrument panel c luster (IPC). I tdoes this by rotating a magnet past astationary hall effect sensor, creatinga resistance code. At this point theIPC will determine if the resistance

code is cor rec t and wi th in anacceptable time frame. If the code iscorrect, the IPC will send a codedpassword to the powertrain controlmodule (PCM). If the PCM receivesthe correct password, it will allow thefuel injectors to operate normally andthe veh ic le w i l l s ta r t and runnormally.

I f the correct res is tance codefrom the lock cylinder is not receivedwithin the acceptable time frame, thevehicle will go into a short tampermode dur ing wh ich the the f tdeterrent system will not allow thevehicle to operate for approximately4 seconds. When this occurs, thesecurity indicator will f lash. Afterthree consecutive fai led tr ies, thesystem will enter into a long tampermode. In this mode, the fuel injectorswill be disabled for approximately 10minutes, and the security indicatorwill be flashing. Please note that inany of the tamper modes, the vehiclemay start, but it will quickly stall.

The Passlock system is designedto prevent vehicle theft even if any ofthe theft deterrent parts are replaced.Passlock eliminates the need for thekey mounted resistor.

Par ts tha t can no longer bereplaced without the possibility of thesystem going into a tamper mode andprevent s ta r t ing a re : the lockcylinder, the instrument panel cluster(IPC), and the powertrain control module (PCM).

In order to initiate the relearn:1 . Hook up your scan too l to

erase any of the passlock/vehicletheft deterrent trouble codes. If thereare any o ther codes , no te thembefore you erase them, so you mayaddress them after the relearn hasbeen completed.

2. With the igni t ion key in the“On” position from the code-clearingstep, attempt to start the vehicle. Atthis point, if the vehicle starts, andthe security light has not illuminated,a relearn is not necessary, and you’redone. If the vehicle starts and stalls,

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leave the key in the “Run” positionand wait for the “Security” light toturn off. This will take approximately10 minutes. At any time during thisrelearn, the light may flash or be ons teady . I f the ign i t ion swi tch i sturned off at any t ime during thisrelearn cycle that the security light isilluminated, the entire cycle must berestarted from the beginning.For most cars , one cyc le w i l l besuf f i c ien t fo r the re learn . I f thevehicle will not start after the firstcyc le , then cont inue the processfrom step #3 to the end. Most trucks wi l l require that youcontinue from step #3 to the end.

3. When the light turns off, turnthe ign i t ion swi tch to the “Of f ”pos i t ion for approx imate ly tenseconds.

4. Next, repeat steps 2 and 3 twomore times for a total of three cycles.After the third time, the new code willbe relearned on the next start attemptwhen the ignition switch is rotatedfrom the “Off” position.

5. From the “Off” position, startthe vehicle, observing the securitylight. If the vehicle starts and runsnormally, and the security light is off,the relearn is complete. If the vehicledoes not s tar t , check for t roublecodes before proceeding further.

PASSKEY 3 ANDPASSKEY 3+

In this system, the vehicle theftdeterrent functions are provided bythe theft deterrent control module.There is a transponder embedded inthe head of the key that becomesenergized by the exciter coils in theign i t ion lock cy l inder when the igni t ion swi tch is turned on. Theenergized transponder now transmitsa signal containing a unique value tothe theft deterrent control module. Ifthe module accepts this value, thenthere is an additional communicationthat takes place between the moduleand the key. If the module and the

key agree, then the module sends thefuel enable password to the PCM. Ifthe PCM recognizes the password,then the veh ic le s ta r ts and runsnormally.

I f any o f the communica t ionbetween the module and the key isincor rec t or the PCM does notrecognize the password, then the fuelinjectors are disabled.

The ign i t ion key i s a normallooking key with no visible contactsas in the Passkey or VATS systems.The transponder is located in the keyhead. The transponder value is fixedand cannot be changed. These keysare usually identified by the lettersPK3, or PK3+ stamped into the steelbody. A relearn will be necessary ifany o f the fo l lowing have beenreplaced: any key, the theft deterrentcontrol module or the powertra incontrol module (PCM).

When the theft control module isbeing replaced, the module will learnthe ex is t ing keys immedia te ly .However, the PCM must learn thenew fuel enable password from thenew module. If you are replacing aPCM with a PCM that has been usedin another veh ic le or has beenremanufactured, then a relearn mustbe performed in order for the PCM tolearn the fuel enable password. Keepin mind that when you perform arelearn on this system, all previouslylearned keys will be erased from thethe f t de te r ren t cont ro l modu le ’smemory. Any additional keys may berelearned immediately after the firstre learn has been per formed byinser t ing the add i t iona l key andturning the ignit ion switch to the“On” position within ten seconds ofremoving the previously learned key.

In order to in i t iate the re learnprocess:

1 . Inser t a master key (b lackhead) into the ignition switch.

2 . Turn to the “On” pos i t ionwi thout s ta r t ing the eng ine . Thesecurity light should illuminate andstay on.

3. Wait approximately 10 minutesor until the security light turns off.

4. Turn off the ignition switch andwait 5 seconds.

5. Repeat steps 2 through 4 twomore times with the same key.

6 . Turn the ign i t ion o f f . Theveh ic le w i l l now learn the keytransponder information on the nextstart cycle.

7. Star t the vehic le . I f vehic les ta r ts and runs normal ly , andsecurity l ight is off, the relearn iscomplete. I f addi t ional keys are to berelearned:

8. Turn the vehicle off.9 . Inser t the nex t key to be

learned and turn the ignition switchto the “On” pos i t ion w i th in 10seconds of removing the previouslyused key.

10. Wait for the security light toturn off. It should happen quickly.You may not even notice the l ightcome on, because it will learn the keytransponder immediately.

11. Repeat steps 8 through 10 forany additional keys.

CRANKSHAFTVARIATION RELEARN(CASE Learn)

”CASE” means: crankshaf t anglesensor error.

A crankshaf t var ia t ion re learnmust be performed if: A diagnostic trouble code of P1336 ispresent.The computer has been replaced or re-programmed.The crankshaft position sensor has beenreplaced.The engine, harmonic balancer, clutch, orflywheel have been: disassembled,removed, or replaced.

The crankshaft position variationlearn ing fea ture enab les thecomputer to compensate for partmanufac tur ing to le rances . Th is

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allows the computer to accuratelydetect an engine misfire throughoutthe engine RPM range. The learningprocess is stored in the computer’smemory and does not have to berepeated unless one or more of theabove conditions are present.

To perform the relearn, proceedas follows: Connect a scan tool tomake sure there are no trouble codesstored in the computer’s memory. Ifthere is any power train trouble codeother than P1336 (Crankshaf tPosition Variation not learned), thecomputer wi l l d isable the re learnfunc t ion unt i l the prob lem tha tcaused the code has been eliminated.A lso , make sure tha t the eng inecoolant (check it when the engine isco ld) and o i l l eve ls a re a t anacceptable level.

1. Set the parking brake and blockthe drive wheels. Make sure that thehood is closed.2. Start the engine and make surethat the engine coolant temperatureis at least 158 degrees F. (70 degrees C.)3. Turn the engine off for at least 10seconds.4. Select the crankshaft positionvariation learn procedure (CASELearn)on your scan tool.5. Make sure that the transmission isin Park. Start the engine.6. Apply the brakes and hold thepedal firmly.7. Follow the scan tool instructions.Remember: That you are going toincrease the engine speed toapproximately 3000 RPM, 4000 RPM,or 5150 RPM. That’s the variationlearn fuel cutoff RPM (dependingupon the engine), and that it’simportant to release the throttle whenthe engine RPM starts to decrease asa result of the fuel cutoff going intoeffect. Failure to do such will result inover revving of the engine, causingpossible engine damage. 8. Once the engine has returned toidle, check the status of Diagnostictrouble code P1336. If the scan tool

indicates that the CASE has beenlearned, the relearn procedure is nowcomplete. If CASE has not beenlearned, check for the presence ofother power train codes. If any exist,correct the problem, then repeat this procedure.

NOTE: If the Crankshaft VariationRelearn is not accessible throughyour scan tool (some t ruckapplications 1998 & later), performthe re learn in the fo l lowingmanner:

1. Turn off all of the accessories.With the Air temperature sensor andCoolant temperature within 5 degrees(Centigrade) of each other, start theengine and let it idle in Park orNeutral for two minutes.2. Accelerate the vehicle to 55 mph atpart throttle. Cruise at 55 mph for 8-10 minutes until the engine reachesoperating temperature.3. Cruise at 55 mph for another 5-6minutes.4. Decelerate to 45 mph withoutusing the brakes, and maintain 45mph for 1 minute.5. Perform 4 deceleration cycles,without using the brakes, of 25seconds each where no specificspeed is necessary. Returning to 45mph for 15 seconds in betweendeceleration cycles.6. Accelerate to 55 mph and cruisefor 2 minutes.7. Stop the vehicle and idle for 2minutes with the brake applied andthe transmission in Drive (automatictrans.) or Neutral (manual trans.)with the clutch depressed. Refer todiagram A on page 8.

BASE IDLE RELEARN

The Computer will reset the idlea i r cont ro l va lve whenever theignition switch is turned to the “On”position, then to the “Off” position.

However, before you return the

car to the customer, i t is best tobr ing the engine up to operat ingtempera ture in Park w i th the a i rconditioning off. Then, turn the airconditioning on. Next, turn the aircond i t ion ing o f f . Next , p lace thet ransmiss ion se lec tor in dr ive .Finally, with the car in Drive, turn theair conditioning on. That’s it!

DIESEL ENGINE TDCOFFSET RELEARNPROCEDURES

This procedure should only beperformed when one or more of thefollowing has occurred:1. A diagnostic trouble code of P1214(TDC offset not established) ispresent.2. The engine has been replaced.3. The front engine cover has beenreplaced.4. The PCM with or without theinjection pump has been replaced.5. The crankshaft position sensor hasbeen replaced.

NOTE: Replacement of the only theinjection pump does not require thisprocedure.

In order to initiate the relearn:1. Hook up your scan tool.2. Start the engine and idle engineuntil coolant temperature is at least170 degrees F.3. Clear any diagnostic trouble codes,if any. Then turn the engine off.4. Turn the ignition switch to the“On” position. Do not start theengine.5. Prepare the PCM to activate theoffset relearn by placing and holdingthe accelerator pedal in the fully openposition for no less than 45 seconds.Then release the pedal.6. Turn the ignition switch to the“Off” position for 30 seconds. Toconfirm that the PCM has powereddown, you should get a “Nocommunication with vehicle” message on your scan tool.

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12. Can I program Bodymodules with the TIS2000software?No, as of July’03 TIS2000 softwarecan only be used to program GMEngine Control Module calibrations.The ability to update GM Body andChassis modules may be availablefrom GM soon.

13. How often is the TIS2000application updated?The TIS application is the PCprogram application. It connects withthe data to compile the calibration forthe specific vehicle. This applicationis occasionally updated on no setschedule.

14. What does off-boardprogramming mean?Off-Board simple refers to the ECMbeing reprogrammed off the vehicle.

15. Can I program on car?Yes. The iflash equipment canprogram on the car as well. See theiflash “User Guide” for more details.

16. How do I select the correctharness?The harness number will be indicatedbeside PCM number on the cross-reference chart ST8873-1. Any PCMnumber not on the chart is currentlynot supported.

17. What is Chrysler VINprogramming?Chrysler PCMs are updated to thelatest calibration by Blue Streak atthe time of remanufacture. Thecustomers VIN needs to be insertedin the PCM for proper function in thevehicles network.

18. What is the latest version formy “Flash” cartridge?It is important to always keep your“Flash” cartridge updated. As ofJuly’03 the latest version is 3.01.Refer to www.bsecorp.com for thelatest version.

19. What are the PCrequirements for flashprogramming?CPU:166 Mhz , Hard Drive:2.5 GB,RAM:32 MB,Video RAM:1 MB,LSCache:256 KB,CD-ROM:16Xspeed,OS:Win 95b/98/ME/2000/XP,ISA/PCI Bus 1 Parallel and 1 serial RS232 port.

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ERROR DESCRIPTION SOLUTION

Communication could not be established w/the 1 BDM / BDM Pro FLASH software is the latest version.E665 Diagnostic Tool! Ensure proper connection 2 BDM / BDM Pro is on main menu and double click iFlash icon

3 The RS-232 connection from PC to BDM / BDM Pro is proper.E666 Access to database denied. 1 Disconnect and reconnect security dongle and restart computer. Repeat if

necessary. E1162 Access to service programming server was denied. 1 Ensure the security Dongle key is properly installed; Select “Configuration”

No hardware key was found. in the TIS menu bar on the top of the screen; Choose “I/O Management” selection under the Configuration pull down menu and the I/O Managementscreen pop up; Click “Properties” button while making sure “Dongle” ishighlighted and the “Properties” screen will pop up; Pull down the Port selection and select “LPT1”; Then click “OK” button; Exit TIS2000 and iflashsoftware; Restart iflash for SPS programming.

M676 The ECU could be a service ECU!!! 1 This is just a message. It indicates the PCM / VCM does not contain a VIN and calibration. Usually seen on DELCO PCMs / VCMs. Continue as usual.

Here is a description of the possible Iflash codes and how to remedy them.

GM SPS Programming Error Codes

Note: All Errors could be a result of the RS232 cable. Make sure that the modular end of the cable (BDM Side) issecure and no strain is placed on the cable.

GM DRIVE CYCLE

IDLE PERIOD - Two minutes with all accessories OFF in Park or Neutral. Cold start with ECT & IAT within 5 degrees Cof one another.

ACCELERATION - Accelerate to 55 MPH at part throttle and cruise at 55 until engine reaches operating temperature(Approx. 8-10 minutes.)

CRUISE - Cruise at 55 MPH for 5-6 minutes.

DECELERATION - Decel to 45 MPH with no brake and maintain 45 for 1 minute. Perform 4 decels of 25 seconds eachreturning to 45 MPH for 15 seconds between decels.

ACCELERATION - Accelerate to 55 MPH for 2 minutes. Cruise.

IDLE - Idle for two minuteswith brake applied and automatic transmission in Drive or manual transmission in Neutralwith clutch depressed.

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IDLE ALL ACC OFF

55 mph

ECT @ OPERATINGTEMP

CRUISE

DECEL DECEL DECEL

2 MIN

2 MIN

25 SE

C

25 SE

C

25 SE

C

25 SE

C

1 MIN

2 MIN

5-6 MIN

8-10 MIN

DECEL

45 mph 45 45 45

55 mph

IN GEARW/BRAKEAPPLIED

Passkey, Passkey II (PK2)

Passlock

Passkey III (PK3), III+ (PK3+)

Passkey III (PK3), III+ (PK3+)

Diagram A

ST9303-SP_ED