Data Communications: Overview Saab 9-7X I

Data Communication Schematic Icons

Data Communication Schematic Icons Icon Icon Definition CAUTION: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling And Enabling. Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs. IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown: The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires. The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

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Body Control Module (BCM) C1 Connector Parts Information

Body Control Module (BCM) C1 Connector Terminal Identification

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Body Control Module (BCM) C2 Connector Parts Information

Body Control Module (BCM) C2 Connector Terminal Identification

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Body Control Module (BCM) C3 Connector Parts Information

Body Control Module (BCM) C3 Connector Terminal Identification

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Data Link Connector (DLC) Connector Parts Information

Data Link Connector (DLC) Connector Terminal Identification

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Liftgate Module (LGM) C1 Connector Parts Information

Liftgate Module (LGM) C1 Connector Terminal Information

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Liftgate Module (LGM) C2 Connector Parts Information

Liftgate Module (LGM) C2 Connector Terminal Identification

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Liftgate Module (LGM) C3 Connector Parts Information

Liftgate Module (LGM) C3 Connector Terminal Identification

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: A DTC U1001 - U1254 Lost Communications with XXX with a history status may indicate the cause of U1000.
2. 3: The modules not communicating are the likely cause of U1000. The modules that are available on the class 2 serial data circuit are listed in the Circuit Description.
3. 7: The module which was not communicating due to a poor connection to the class 2 serial data circuit may have set DTC U1001 - U1254 Lost Communications with XXX for those modules that it was monitoring.
4. 10: The modules which can communicate indicate the module which cannot communicate. You must clear the serial data communication DTCs from these modules to avoid future misdiagnosis.
5. 13: If all modules are communicating, the module which set U1000 may have done so due to some other condition.
6. 15: The module which set U1000 is the likely cause of the malfunction.

DTC U1000

The number below refers to the step number on the diagnostic table.

1. 7: The module which was not communicating on the class 2 serial data circuit may have set Loss of Communication DTCs for those modules that it was monitoring.

DTC U1001-U1254

The numbers below refer to the step numbers on the diagnostic table.

1. 6: The class 2 serial data circuit is shorted to voltage or ground. The condition may be due to the wiring or due to a malfunction in one of the modules. When testing the wire for a short, make sure there is not a module connected to the wire being tested. This test isolates the splice pack SP306 serial data circuits.
2. 14: This test isolates the splice pack SP205 serial data circuits.
3. 20: If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
4. 21: The communication malfunction may have prevented diagnosis of the customer complaint.

DTC U1300, U1301, or U1305 (5.3L)

The number below refers to the step number on the diagnostic table.

1. 4: If the battery positive voltage and ground circuits of the DLC are functioning properly, the malfunction must be due to the scan tool.

Scan Tool Does Not Power Up

The numbers below refer to the step numbers on the diagnostic table.

1. 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: The body control module (BCM) The communication interface module (OnStar®), w/UE1 The digital radio receiver (DRR), w/U2K The driver door module (DDM) The driver seat module (DSM), w/AAB The DVD player The electronic brake control module (EBCM) The HVAC control module The HVAC control module - rear auxiliary The inflatable restraint sensing and diagnostic module (SDM) The instrument panel cluster (IPC) The liftgate control module (LGM) The passenger door module (PDM) The powertrain control module (PCM) The radio The transfer case shift control module (TCSCM), w/4WD The theft deterrent control module (VTD)
2. 3: The following DTCs may be retrieved with a history status, but are not the cause of the present condition. U1300 U1301 U1305
3. 6: A state of health (SOH) 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.
4. 7: Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
5. 10: A poor connection at the DLC terminal of the splice pack SP205 would cause this condition but will not set a DTC.
6. 11: This step may eliminate the loop created by the PCM and VTD from failure cause.
7. 12: An open in the class 2 serial data circuit between the DLC and splice pack SP205 will prevent the scan tool from communicating with any module. This condition will not set a DTC.
8. 14: The class 2 serial data circuit is shorted to voltage or ground. The condition may be due to the wiring or due to a malfunction in one of the modules. When testing the wire for a short, make sure there is not a module connected to the wire being tested. This test isolates the BCM class 2 serial data circuits.
9. 16: This test isolates the PCM class 2 serial data circuits.
10. 18: The BCM detects that the ignition is ON and sends the appropriate power mode message to the other modules. Therefore, the BCM must remain connected to the DLC for any other module to communicate with the scan tool. This test isolates the splice pack SP306 serial data circuits.
11. 23: This test isolates the rest of the splice pack SP205 serial data circuits.
12. 27: If there are no current DTCs that begin with a "U", the communication malfunction has been repaired.
13. 28: The communication malfunction may have prevented diagnosis of the customer complaint.

Scan Tool Does Not Communicate with Class 2 Device (4.2L)

The numbers below refer to the step numbers on the diagnostic table.

1. 2: A current DTC U1300 or U1301, may be retrieved only from the engine control module (ECM), because the ECM is connected to both class 2 and high speed GMLAN buses, but it communicates with the scan tool on high speed GMLAN bus only.
2. 3: 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 scan tool communicates with the following modules on the class 2 serial data circuit: The body control module (BCM) The communication interface module (OnStar®), w/UE1 The digital radio receiver (DRR), w/U2K The driver door module (DDM) The driver seat module (DSM), w/AAB The DVD player The electronic brake control module (EBCM) The HVAC control module The HVAC control module - rear auxiliary The inflatable restraint sensing and diagnostic module (SDM) The instrument panel cluster (IPC) The liftgate control module (LGM) The passenger door module (PDM) The radio The transfer case shift control module (TCSCM), w/4WD The theft deterrent control module (VTD)
3. 7: Data link connector terminals 2 and 5 provide the connection to the class 2 serial data circuit and the signal ground circuit respectively.
4. 9: A poor connection at splice pack SP205 will cause this condition but will not set a DTC.
5. 10: An open in the class 2 serial data circuit between the DLC and splice pack SP205 will prevent the scan tool from communicating with any module on the class 2 network. This condition will not set a DTC.

Scan Tool Does Not Communicate with Class 2 Device (5.3L)

The numbers below refer to the step numbers on the diagnostic table.

1. 2: A partial malfunction in the high speed GMLAN serial data circuits uses a different procedure from a total malfunction of the high speed GMLAN data circuits. The following modules are connected to the high speed GMLAN serial data circuits: ECM, for 5.3L Transmission control module (TCM)
2. 5: Data link connector terminals 6 and 14 provide the connection to the GMLAN serial data high circuit and the GMLAN serial data low circuit respectively.
3. 12: The communication malfunction may have prevented diagnosis of the customer complaint.

Scan Tool Does Not Communicate with High Speed GMLAN Device

See also:
• Master Electrical Component List