CTS V8-5.7L VIN S (2005)
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Steps 22 - 24
The numbers below refer to the step numbers on the diagnostic table.
2. A partial malfunction in the class 2 serial data circuit uses a different procedure from a total malfunction of the class 2 serial data circuit. The
following modules communicate on class 2 serial data bus:
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The audio amplifier (AMP)
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The dash integration module (DIM)
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The digital radio receiver (DRR)
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The driver door module (DDM)
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The driver door switch assembly (DDSA)
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The electronic brake control module (EBCM)
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The engine control module (ECM) for LY7/LP1 models communicates on both class 2 and high speed GMLAN links and communicate with
the scan tool on high speed GMLAN
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The front passenger door module (FPDM)
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The HVAC control module
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The inflatable restraint sensing and diagnostic module (SDM)
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The instrument panel cluster (IPC)
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The left rear door module (LRDM)
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The memory seat module (MSM) w/A45
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The radio
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The radio antenna module
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The rear integration module (RIM)
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The right rear door module (RRDM)
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The theft deterrent control module (VTD)
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The TV antenna module
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The vehicle communication interface module (VCIM)
3. The following DTCs may be retrieved with a history status, but are not the cause of the present condition.
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U1300
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U1301
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U1305
6. A state of health DTC with a history status may be present along with a U1000 code having a current status. This indicates that the malfunction
occurred when the ignition was ON.
7. Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
10. This step takes out from the class 2 bus the modules connected to splice pack SP303, excepting SDM and RIM.
11. This step takes out from the class 2 bus the modules connected to splice pack SP300, excepting IPC.
13. This test isolates the class 2 serial data circuit between DLC and DIM.
18. This test localizes the class 2 serial data circuit of the suspected bus, that is shorted.
22. If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
23. The communication malfunction may have prevented diagnosis of the customer complaint.