SRX RWD V8-4.6L VIN A (2006)
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SP200
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The data link connector (DLC)
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The theft deterrent control module (VTD)
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The digital video disc (DVD) player
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SP304
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The right rear door module (RRDM)
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The rear seat module (RSM)
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The radio antenna module
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The TV antenna module
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The vehicle communication interface module (VCIM)
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The digital radio receiver (DRR)
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The front passenger door module (FPDM)
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The electronic suspension control (ESC) module
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SP300
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The audio amplifier (AMP)
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The left rear door module (LRDM)
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The driver door switch assembly (DDSA)
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The driver door module (DDM)
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The memory seat module (MSM) w/A45
Refer to Data Link Connector (DLC) Schematics in order to familiarize yourself with the architecture of the class 2 serial data circuit.
GMLAN CIRCUIT DESCRIPTION
The data link connector (DLC) allows a scan tool to communicate with the high speed GMLAN serial data circuit. The serial data is transmitted on 2
twisted wires that allow speed up to 500 Kbps. The twisted pair is terminated with two 120 ohm resistors, one is internal to the engine control module
(ECM) and the other is internal to the transmission control module (TCM). The resistors are used to reduce noise on the high speed GMLAN bus
during normal vehicle operation. The high speed GMLAN is a differential bus. The high speed GMLAN serial data bus (+) and high speed GMLAN
serial data (-) are driven to opposite extremes from a rest or idle level. The idle level which is approximately 2.5 volts is considered a recessive
transmitted data and is interpreted as a logic 1. Driving the lines to their extremes adds 1 volt to high speed GMLAN serial data bus (+) and subtracts
1 volt from high speed GMLAN serial data bus (-) wire. This dominant state is interpreted as a logic 0.
The modules on the GMLAN serial data line are:
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The ECM
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The TCM
KEYWORD SERIAL DATA LINE (TR7)
The keyword protocols utilize a single wire bi-directional data line between the modules and the scan tool. The message structure is a request and
response arrangement. The keyword serial data line is used for scan tool diagnostics only. The modules do not exchange data on this circuit.
The modules on the GMLAN serial data line are:
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Headlamp - Left
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Headlamp - Right
