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Pinpoint Test U: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, One Or More Modules Are Not Respo




Communications Network

Pinpoint Tests

Pinpoint Test U: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, One Or More Modules Are Not Responding During Network Test

Normal Operation

The Medium Speed Controller Area Network (MS-CAN) uses an unshielded twisted pair cable. (HS-CAN +) and (HS-CAN -) provide the network connection to all modules on the network.

In the event that 1 of the 2 network circuits (MS-CAN + or MS-CAN -) becomes open to a module on the network, unreliable network communication to all modules on the network may result.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

PINPOINT TEST U: INTERMITTENT NO MS-CAN COMMUNICATION, ONE OR MORE MODULES ARE NOT RESPONDING DURING NETWORK TEST

NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the Pinpoint Test. Inspection and Verification

NOTE: Various network DTCs set while disabling modules in this test procedure which need to be cleared after the diagnostic procedure is completed.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect.

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U1 CHECK THE DLC PINS FOR DAMAGE


- Ignition OFF.
- Disconnect the scan tool cable from the Data Link Connector (DLC).
- Inspect DLC pins 3 and 11 for damage.




- Are DLC pins 3 and 11 OK?

Yes
GO to U2.

No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.

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U2 CHECK THE MS-CAN TERMINATION RESISTANCE


- Disconnect: Negative Battery Cable.
- Measure the resistance between the DLC C251-3, circuit VDB06 (GY/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.




- Is the resistance between 54 and 66 ohms?

Yes
GO to U3.

No
CONNECT the negative battery cable. GO to Pinpoint Test V. Pinpoint Test V: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding

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U3 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND


- Measure the resistance between the DLC C251-3, circuit VDB06 (GY/OG), harness side and ground; and between the DLC C251-11, circuit VDB07 (VT/OG), harness side and ground.




- Are the resistances greater than 1,000 ohms?

Yes
CONNECT the negative battery cable. GO to U4.

No
CONNECT the negative battery cable. GO to Pinpoint Test V. Pinpoint Test V: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding

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U4 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between the DLC C251-3, circuit VDB06 (GY/OG), harness side and ground; and between the DLC C251-11, circuit VDB07 (VT/OG), harness side and ground.




- Is the voltage greater than 6 volts?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.

No
GO to U5.

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U5 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE HVAC MODULE AND GPSM DISABLED


- Disconnect: SJB Fuses 15 (10A) and 37 (10A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuses. If the vehicle is equipped with a Global Positioning System Module (GPSM), GO to U6.

If the vehicle is not equipped with a GPSM, GO to Pinpoint Test I. Pinpoint Test I: The HVAC Module Does Not Respond To The Scan Tool

No
INSTALL the removed fuses. GO to U7.

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U6 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE HVAC MODULE DISCONNECTED


- Disconnect: HVAC module C2357a EMTC or C228a EATC.
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
CONNECT the HVAC module. GO to Pinpoint Test i. Pinpoint Test I: The HVAC Module Does Not Respond To The Scan Tool

No
CONNECT the HVAC module. GO to Pinpoint Test t. Pinpoint Test T: The Global Positioning System Module (GPSM) Does Not Respond To The Scan Tool

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U7 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE ACM DISABLED


- Disconnect: SJB Fuse 39 (20A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test K. Pinpoint Test K: The Audio Control Module (ACM) Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U8.

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U8 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE SJB DISABLED


- Disconnect: SJB Fuse 5 (10A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test H. Pinpoint Test H: The Smart Junction Box (SJB) Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U9.

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U9 VERIFY VEHICLE EQUIPMENT - DSM


- Inspect the vehicle for a DSM.
- Is the vehicle equipped with a DSM?

Yes
GO to U10.

No
GO to U11.

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U10 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE DSM DISABLED


- Disconnect: SJB Fuse 2 (15A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test Q. Pinpoint Test Q: The Power Running Board (PRB) Module Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U11.

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U11 VERIFY VEHICLE EQUIPMENT - LTM


- Inspect the vehicle for a Liftgate/Trunk Module (LTM).
- Is the vehicle equipped with an LTM?

Yes
GO to U12.

No
GO to U13.

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U12 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE LTM DISABLED


- Disconnect: Battery Junction Box (BJB) Fuse 36 (30A) and SJB Fuse 14 (10A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuses. GO to Pinpoint Test J. Pinpoint Test J: The Liftgate/Trunk Module (LTM) Does Not Respond To The Scan Tool

No
INSTALL the removed fuses. GO to U13.

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U13 VERIFY VEHICLE EQUIPMENT - AUDIO RCU MODULE AND SDARS MODULE


- Inspect the vehicle for an audio Rear Control Unit (RCU) module and/or a Satellite Digital Audio Receiver System (SDARS) module.
- Is the vehicle equipped with any of the following: an audio RCU module, and/or a SDARS module?

Yes
GO to U14.

No
GO to U17.

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U14 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE AUDIO RCU MODULE AND SDARS MODULE DISABLED


- Disconnect: SJB Fuse 3 (15A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to U15.

No
INSTALL the removed fuse. GO to U17.

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U15 VERIFY VEHICLE EQUIPMENT - SDARS MODULE


- Inspect the vehicle for a SDARS module.
- Is the vehicle equipped with a SDARS module?

Yes
GO to U16.

No
GO to Pinpoint Test N. Pinpoint Test N: The Audio Rear Control Unit (RCU) Module Does Not Respond To The Scan Tool

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U16 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE SDARS MODULE DISABLED


- Disconnect: SDARS Module C3290.
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
GO to Pinpoint Test M. Pinpoint Test M: The Satellite Digital Audio Receiver System (SDARS) Module Does Not Respond To The Scan Tool

No
GO to Pinpoint Test N. Pinpoint Test N: The Audio Rear Control Unit (RCU) Module Does Not Respond To The Scan Tool

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U17 VERIFY VEHICLE EQUIPMENT - AUDIO DSP MODULE


- Inspect the vehicle for an audio Digital Signal Processing (DSP) module.
- Is the vehicle equipped with an audio DSP module?

Yes
GO to U18.

No
GO to U19.

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U18 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE AUDIO DSP MODULE DISABLED


- Disconnect: SJB Fuse 38 (20A) and 40 (20A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuses. GO to Pinpoint Test L. Pinpoint Test L: The Audio Digital Signal Processing (DSP) Module Does Not Respond To The Scan Tool

No
INSTALL the removed fuses. GO to U19.

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U19 VERIFY VEHICLE EQUIPMENT - DCSM


- Inspect the vehicle for a Dual Climate Controlled Seat Module (DCSM).
- Is the vehicle equipped with a DCSM?

Yes
GO to U20.

No
GO to U21.

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U20 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE DCSM DISABLED


- Disconnect: BJB Fuse 67 (40A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test P. Pinpoint Test P: The Dual Climate Controlled Seat Module (DCSM) Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U21.

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U21 VERIFY VEHICLE EQUIPMENT - PRB MODULE


- Inspect the vehicle for a Power Running Board (PRB) module.
- Is the vehicle equipped with a PRB module?

Yes
GO to U22.

No
GO to U23.

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U22 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE PRB MODULE DISABLED


- Disconnect: BJB Fuse 11 (40A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test Q. Pinpoint Test Q: The Power Running Board (PRB) Module Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U23.

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U23 VERIFY VEHICLE EQUIPMENT - PAM


- Inspect the vehicle for a Parking Aid Module (PAM).
- Is the vehicle equipped with a PAM?

Yes
GO to U24.

No
GO to U25.

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U24 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE PAM DISABLED


- Disconnect: SJB Fuse 35 (10A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuse. GO to Pinpoint Test R. Pinpoint Test R: The Parking Aid Module (PAM) Does Not Respond To The Scan Tool

No
INSTALL the removed fuse. GO to U25.

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U25 VERIFY VEHICLE EQUIPMENT - APIM


- Inspect the vehicle for a Accessory Protocol Interface Module (APIM).
- Is the vehicle equipped with APIM?

Yes
GO to U26.

No
GO to U27.

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U26 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE APIM DISABLED


- Disconnect: APIM C3342.
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
CONNECT the APIM. GO to Pinpoint Test S. Pinpoint Test S: The Accessory Protocol Interface Module (APIM) Does Not Respond To The Scan Tool

No
CONNECT the APIM. GO to U27.

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U27 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE IC DISABLED


- Disconnect: SJB Fuse 26 (10A) and 29 (5A).
- Enter the following diagnostic mode on the scan tool: Network Test.
- Repeat the network test.
- Do all other modules pass the network test?

Yes
INSTALL the removed fuses. GO to Pinpoint Test C. Pinpoint Test C: The Instrument Cluster (IC) Does Not Respond To The Scan Tool

No
INSTALL the removed fuses. An intermittent fault is not present. GO to Pinpoint Test V. Pinpoint Test V: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding

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