Ecu needed .. Help

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
188
Location
unknown at this time.
it's purpose is to prevent vehicle theft. and it can be bypassed. but you pretty much have to fix what's wrong first. it is not really an encoded key in your particular system. there are several versions of passlock/passkey and yours should not require an "encoded key". you can try this method to see if it will extract bcm codes for you. that should aid in the diagnosis. sometimes things like disconnecting a battery may contribute to this issue but a simple relearn fixes it.

Body Control Module (B Codes) For additional information refer to Body Control Module in Computers and Control Systems.

In the diagnostic mode, the BCM displays any Diagnostic Trouble Codes (DTCs) that are stored in memory. The DTCs are displayed as flash codes through the security LED indicator lamp on the console. During normal operation, if the BCM detects a fault in a monitored system, there is no flash code to indicate to the customer that a fault has occurred. However, the driver may detect a system malfunction. System faults are stored by the BCM as CURRENT or HISTORY DTCs. A current DTC means that a fault was present when the diagnostic mode was entered. A history DTC indicates that the following conditions occurred:


  • A fault occurred sometime after the BCM was installed in the vehicle.
  • A fault occurred since the last time the DTCs were cleared.
  • The fault may not be currently present.
If a current DTC is stored, the associated history DTC will always be stored.

When working on systems that are controlled by the BCM, the technician should always refer to this section and check for DTCs.

Enter diagnostics by performing the following steps:


  • Turn the ignition switch to the RUN position in order to disarm the universal theft deterrent system, if equipped.
  • Turn the ignition switch to the OFF position.
  • Remove the RADIO fuse 17 from the instrument panel fuse block.
  • Turn the ignition switch to the ACC position. This action will enter the program mode. Two audible warning tones will occur for mode verification.
  • Within 5 seconds , turn the ignition switch to the OFF position. Immediately (within one second ) turn the ignition switch back to the ACC position. This action will enter the diagnostic mode. Three audible warning tones will occur for mode verification.
The BCM will begin to flash DTCs 4 seconds after entering the diagnostic mode. Each flash of the security LED indicator lamp on the console represents a number. For example, one flash followed by two quick flashes represents a code 12. Each code is displayed 3 times before the next code is displayed. Stored DTCs are displayed in numerical order. Once the last code is displayed, the list begins over again with the first code. The display continues until the diagnostic mode is exited.

While in the diagnostic mode, a transition of certain BCM inputs from active to inactive, or vice versa, will cause the BCM to actively respond. For example, if a door lock switch is depressed the BCM will perform the following actions:


  1. Flash the FASTEN SEATBELT indicator.
  2. Sound a single audible warning tone.
The BCM will also respond in the same way if the rear compartment lid or a door is opened or closed. This is due to the transition at the door jamb switch or the rear compartment lid ajar indication switch input. In all cases, the BCM will also attempt to perform the operation normally performed by the switch transition.

The BCM will also respond to a change at either the shock sensor tamper input or the shock sensor shock input. The tamper input is activated by minor blows to the vehicle. The shock input is activated by heavy blows to the vehicle, or by tapping on the exposed shock sensor. In the diagnostic mode, if either the tamper input or the shock input becomes active the following actions will occur:


  • The BCM will activate the horn relay.
  • The horn relay will cause the horns to chirp.
  • The BCM will sound an audible warning tone.
Any transition at the interior lamps command input while in the diagnostic mode will cause the BCM to perform the following actions:


  • Flash the FASTEN SEATBELT indicator lamp.
  • Sound an audible warning tone.
  • Flash the courtesy lamps.
The above actions can be caused by such transitions as switching the interior lamps switch to the ON or OFF position.






Body Control Module (B Codes) For additional information refer to Body Control Module in Computers and Control Systems.

In the diagnostic mode, the BCM displays any Diagnostic Trouble Codes (DTCs) that are stored in memory. The DTCs are displayed as flash codes through the security LED indicator lamp on the console. During normal operation, if the BCM detects a fault in a monitored system, there is no flash code to indicate to the customer that a fault has occurred. However, the driver may detect a system malfunction. System faults are stored by the BCM as CURRENT or HISTORY DTCs. A current DTC means that a fault was present when the diagnostic mode was entered. A history DTC indicates that the following conditions occurred:


  • A fault occurred sometime after the BCM was installed in the vehicle.
  • A fault occurred since the last time the DTCs were cleared.
  • The fault may not be currently present.
If a current DTC is stored, the associated history DTC will always be stored.

When working on systems that are controlled by the BCM, the technician should always refer to this section and check for DTCs.

Enter diagnostics by performing the following steps:


  • Turn the ignition switch to the RUN position in order to disarm the universal theft deterrent system, if equipped.
  • Turn the ignition switch to the OFF position.
  • Remove the RADIO fuse 17 from the instrument panel fuse block.
  • Turn the ignition switch to the ACC position. This action will enter the program mode. Two audible warning tones will occur for mode verification.
  • Within 5 seconds , turn the ignition switch to the OFF position. Immediately (within one second ) turn the ignition switch back to the ACC position. This action will enter the diagnostic mode. Three audible warning tones will occur for mode verification.
The BCM will begin to flash DTCs 4 seconds after entering the diagnostic mode. Each flash of the security LED indicator lamp on the console represents a number. For example, one flash followed by two quick flashes represents a code 12. Each code is displayed 3 times before the next code is displayed. Stored DTCs are displayed in numerical order. Once the last code is displayed, the list begins over again with the first code. The display continues until the diagnostic mode is exited.

While in the diagnostic mode, a transition of certain BCM inputs from active to inactive, or vice versa, will cause the BCM to actively respond. For example, if a door lock switch is depressed the BCM will perform the following actions:


  1. Flash the FASTEN SEATBELT indicator.
  2. Sound a single audible warning tone.
The BCM will also respond in the same way if the rear compartment lid or a door is opened or closed. This is due to the transition at the door jamb switch or the rear compartment lid ajar indication switch input. In all cases, the BCM will also attempt to perform the operation normally performed by the switch transition.

The BCM will also respond to a change at either the shock sensor tamper input or the shock sensor shock input. The tamper input is activated by minor blows to the vehicle. The shock input is activated by heavy blows to the vehicle, or by tapping on the exposed shock sensor. In the diagnostic mode, if either the tamper input or the shock input becomes active the following actions will occur:


  • The BCM will activate the horn relay.
  • The horn relay will cause the horns to chirp.
  • The BCM will sound an audible warning tone.
Any transition at the interior lamps command input while in the diagnostic mode will cause the BCM to perform the following actions:


  • Flash the FASTEN SEATBELT indicator lamp.
  • Sound an audible warning tone.
  • Flash the courtesy lamps.
The above actions can be caused by such transitions as switching the interior lamps switch to the ON or OFF position.



with that you may be able to extract the body codes we might be able tell how the system is broken and why the light is constantly on. also may need a high end scanner or tech2 to communicate with the securtiy/evo module to get codes as well.

one more thing don't you or your friends or the shops go popping open any more modules like pcm or sensors.
 
Last edited:

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
188
Location
unknown at this time.
here is the auto programming auto re-learn:

PASSLOCK REPROGRAMMING AUTO LEARN

IMPORTANT: If a new vehicle/powertrain control module (VCM/PCM) is being installed for the first the manufacturing enable bit will be set and the auto learn procedure may not be necessary.

The following procedure allows for anyone to reprogram the EVO/PASSLOCK module learned data code with any tools, other than the scan tool, when any of the following parts are replaced:


  • The EVO/PASSLOCK module
  • The PASSLOCK sensor
  • The VCM/PCM
  • The EVO/PASSLOCK module will set the DTC B3031 module in the learn mode when entering the reprogramming procedure.
IMPORTANT: Erase the PASSLOCK related diagnostic trouble codes (DTCs) that are stored in the VCM/PCM. If there are any powertrain related DTCs, record these DTCs then:

The following is the Auto Learn Procedure:


  1. Insure the ignition key is in the "ON" position.
  2. Clear all EVO/PASSLOCK module and VCM/PCM DTCs. Record and refer any VCM/PCM DTCs to:
  3. Momentarily rotate the ignition key to the "CRANK" position (Do NOT start the vehicle), then release it to the "RUN" position (Do NOT key "OFF" in the process).
  4. Wait 10 minutes. Observe the "SECURITY" indicator. Refer to the following list for the appropriate responses:

    1. If the PASSLOCK sensor was replaced the "SECURITY" indicator will flash for the 10 minutes duration.
    2. If the EVO/PASSLOCK module was replaced, the ""SECURITY"" indicator will flash for a few seconds and then remain "ON" for the remainder of the 10 minutes duration.
    3. If the VCM/PCM was replaced with a new programmed VCM/PCM and connected to the vehicle for the first time, the vehicle will start and this procedure may not be necessary.
    4. If the replacement VCM/PCM was connected to any vehicle at any other time, even momentarily, the "SECURITY" indicator will flash for a few seconds and then remain "ON" for the 10 minutes duration.

  1. The "SECURITY" indicator will transition from flashing to "ON" briefly to "OFF" after 10 minutes if remaining in the ignition "ON" position.
  2. Turn the ignition switch to the "OFF" position and wait for 10 seconds.
  3. Repeat steps 3-6 two more times. The new security code is ready to be communicated among the PASSLOCK sensor, EVO/PASSLOCK module and VCM/PCM. The new password is learned on the next ignition lock cylinder cycle from "OFF" to "CRANK" to "ON" (start attempt).
 
OP
OP
saif najd

saif najd

Full Access Member
Joined
Dec 25, 2012
Posts
567
Reaction score
0
Thank you for the info, I should get back to you after I find such scan tool that wilk allow me to do this
 

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
188
Location
unknown at this time.
those ones are very costly. might get lucky and find one for under a grand USD. if there are a lot of your vehicles in your area your mechs should invest in them. they can do wonders.
 
OP
OP
saif najd

saif najd

Full Access Member
Joined
Dec 25, 2012
Posts
567
Reaction score
0
those ones are very costly. might get lucky and find one for under a grand USD. if there are a lot of your vehicles in your area your mechs should invest in them. they can do wonders.

The problem is GM did a big I mean the worst mistake they can do (we use to have 3 GM dealers in the country) GM chooses the worst one of them to the only one (because he was the best seller of them all but actually he was the cheapest and we do buy from him to do all the after sales services by the other 2 he was and still the worst car dealer I have seen and faced in my life!) So I visited them and they refuse to do or supply any service or parts because it is 98 model .. Quote "to old to maintain.." :banghead:

So I am looking around for who have the Scaner :mad: :mad: :mad: :mad:
 

SunlitComet

OBS Jedi-Do Good
Joined
Sep 30, 2010
Posts
16,206
Reaction score
188
Location
unknown at this time.
yeah i would complain to a regional manager about that. if they have to charge more then they should say so. but i know they don't. they are looking for easier profiting from easy work i think. to bad i can't leave there. i would probably make a killing assuming people were willing to pay for the cost of importing parts.
 
OP
OP
saif najd

saif najd

Full Access Member
Joined
Dec 25, 2012
Posts
567
Reaction score
0
yeah i would complain to a regional manager about that. if they have to charge more then they should say so. but i know they don't. they are looking for easier profiting from easy work i think. to bad i can't leave there. i would probably make a killing assuming people were willing to pay for the cost of importing parts.

Aaaah when you say willing you are giving a choice! But the actual fact we have no choice look at me I have to import everything to maintain the Tahoe :mad:
 
OP
OP
saif najd

saif najd

Full Access Member
Joined
Dec 25, 2012
Posts
567
Reaction score
0
importing foreign car parts business in your future?

Yes, and there are few new regulations just came up in this country that looks ugly but actually its gold if you now how to take advantage of it
 

Forum statistics

Threads
132,737
Posts
1,873,412
Members
97,565
Latest member
Champ74
Top