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WorldClassRS · 10-03-2009, 12:58 AM

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Service Information
2010 Chevrolet Camaro | Camaro (VIN F)Service Manual | Engine | Engine Controls and Fuel - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L | Description and Operation | Document ID: 2218083
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Immobilizer Description and Operation
The immobilizer system functions are provided by the body control module (BCM) and the engine control module (ECM), as well as any modules which store and report the security code.

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coil surrounding the ignition lock cylinder. This exciter coil is part of the theft deterrent module. The energized transponder transmits a signal that contains its unique value, which is received by the BCM. The BCM then compares this value to a value stored in memory. The BCM also monitors various modules to determine that the stored security code matches.

If the both the security code and the value received from the transponder match, the BCM will send the prerelease password via serial data to the ECM. If the transponders unique value is incorrect or the security code does not match, the BCM will send the fuel disable message to the ECM.

When the ECM receives the BCM prerelease password, the ECM will challenge the password. The ECM sends this challenge back to the BCM via serial data. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting.

The components of the theft system are as follows:

• BCM

• ECM

• Theft deterrent module

• Ignition key (Transponder)

• Security indicator

• Various modules which store and report the security code

Body Control Module (BCM)
The immobilizer system is an integral part of the BCM and is controlled internally within the BCM. The BCM can learn up to 8 keys (transponder values).

The BCM uses the following inputs:

• Security code exchange with various modules

• Transponder identification from theft deterrent module

The BCM uses the following outputs:

• Prerelease password communication with ECM

• Challenge/response with ECM

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the BCM. The BCM then compares this value to the learned key code stored in memory. The BCM then performs one of the following functions:

• If the transponder value matches the values stored in the BCM memory, the BCM will send the prerelease password to the ECM via serial data.

• If the transponders unique value does not match the value stored in the BCM, the BCM will send the start disable message to the ECM via serial data.

• If the BCM is unable to measure the ignition key transponder value, the BCM will not send any messages to the ECM.

Engine Control Module (ECM)
When the ECM receives the BCM prerelease password, the ECM will challenge the password. The ECM sends this challenge back to the BCM via the serial data circuit. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting.

The ECM will disable vehicle starting if any of the following conditions occur:

• The prerelease password is invalid.

• The start disable password is sent by the BCM.

• No passwords are received. There is no communication with the BCM.

• The BCM calculated response to the challenge does not equal the calculation performed by the ECM.

Theft Deterrent Module
The theft deterrent module contains an exciter coil which surrounds the ignition cylinder. The exciter passively powers the transponder located in the ignition key when the key is in the ignition. When powered, the transponder transmits its unique value to the theft deterrent module, which is then relayed to the BCM via a LIN serial data circuit. The theft deterrent module also receives B+ and ground from the BCM.

The Ignition Key (Transponder)
The ignition key for PassKey III+ (PK3+) equipped vehicles is a standard ignition key with a transponder located in the plastic head of the key. The transponder value is fixed and unable to be changed. The immobilizer system uses the ignition key transponder value to determine if a valid ignition key is being used to start the vehicle. There are approximately 3 trillion possible transponder values. There are no visible electrical contacts. The keys are identified by + symbol in a circle stamped into the steel shank of the key.

Security Code
Various modules throughout the vehicle learn a specific security code during the module programming process. The security code learned by each individual module matches the security code stored in the BCM, which is the security code master. Prior to starting, each of the modules which store a security code will compare their code to that of the code stored in the BCM. If all the codes match, the engine starting process will continue. If the security codes do not match, engine starting will be disabled.

Security Indicator
The BCM will command the instrument panel cluster to illuminate the security indicator when the ignition key is in the ON position to indicate a fault is noted in the immobilizer system and when the engine starting is disabled.
© 2009 General Motors Corporation. All rights reserved.

10-03-2009, 12:58 AM	#79
WorldClassRS Drives: 2010 RJT LT/RS Join Date: Jun 2009 Location: Illinois Posts: 40	xTooltipElement Service Information 2010 Chevrolet Camaro \| Camaro (VIN F)Service Manual \| Engine \| Engine Controls and Fuel - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L \| Description and Operation \| Document ID: 2218083 -------------------------------------------------------------------------------- Immobilizer Description and Operation The immobilizer system functions are provided by the body control module (BCM) and the engine control module (ECM), as well as any modules which store and report the security code. When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coil surrounding the ignition lock cylinder. This exciter coil is part of the theft deterrent module. The energized transponder transmits a signal that contains its unique value, which is received by the BCM. The BCM then compares this value to a value stored in memory. The BCM also monitors various modules to determine that the stored security code matches. If the both the security code and the value received from the transponder match, the BCM will send the prerelease password via serial data to the ECM. If the transponders unique value is incorrect or the security code does not match, the BCM will send the fuel disable message to the ECM. When the ECM receives the BCM prerelease password, the ECM will challenge the password. The ECM sends this challenge back to the BCM via serial data. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting. The components of the theft system are as follows: • BCM • ECM • Theft deterrent module • Ignition key (Transponder) • Security indicator • Various modules which store and report the security code Body Control Module (BCM) The immobilizer system is an integral part of the BCM and is controlled internally within the BCM. The BCM can learn up to 8 keys (transponder values). The BCM uses the following inputs: • Security code exchange with various modules • Transponder identification from theft deterrent module The BCM uses the following outputs: • Prerelease password communication with ECM • Challenge/response with ECM When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the BCM. The BCM then compares this value to the learned key code stored in memory. The BCM then performs one of the following functions: • If the transponder value matches the values stored in the BCM memory, the BCM will send the prerelease password to the ECM via serial data. • If the transponders unique value does not match the value stored in the BCM, the BCM will send the start disable message to the ECM via serial data. • If the BCM is unable to measure the ignition key transponder value, the BCM will not send any messages to the ECM. Engine Control Module (ECM) When the ECM receives the BCM prerelease password, the ECM will challenge the password. The ECM sends this challenge back to the BCM via the serial data circuit. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting. The ECM will disable vehicle starting if any of the following conditions occur: • The prerelease password is invalid. • The start disable password is sent by the BCM. • No passwords are received. There is no communication with the BCM. • The BCM calculated response to the challenge does not equal the calculation performed by the ECM. Theft Deterrent Module The theft deterrent module contains an exciter coil which surrounds the ignition cylinder. The exciter passively powers the transponder located in the ignition key when the key is in the ignition. When powered, the transponder transmits its unique value to the theft deterrent module, which is then relayed to the BCM via a LIN serial data circuit. The theft deterrent module also receives B+ and ground from the BCM. The Ignition Key (Transponder) The ignition key for PassKey III+ (PK3+) equipped vehicles is a standard ignition key with a transponder located in the plastic head of the key. The transponder value is fixed and unable to be changed. The immobilizer system uses the ignition key transponder value to determine if a valid ignition key is being used to start the vehicle. There are approximately 3 trillion possible transponder values. There are no visible electrical contacts. The keys are identified by + symbol in a circle stamped into the steel shank of the key. Security Code Various modules throughout the vehicle learn a specific security code during the module programming process. The security code learned by each individual module matches the security code stored in the BCM, which is the security code master. Prior to starting, each of the modules which store a security code will compare their code to that of the code stored in the BCM. If all the codes match, the engine starting process will continue. If the security codes do not match, engine starting will be disabled. Security Indicator The BCM will command the instrument panel cluster to illuminate the security indicator when the ignition key is in the ON position to indicate a fault is noted in the immobilizer system and when the engine starting is disabled. © 2009 General Motors Corporation. All rights reserved.