Pinpoint Test H: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, Communication Can Be Intermittent
Communications Network
Pinpoint Tests
Pinpoint Test H: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, Communication Can Be Intermittently Established
Normal Operation
The Medium Speed Controller Area Network (MS-CAN) uses an unshielded twisted pair cable, circuits VDB06 (GY/OG) and VDB07 (VT/OG). The Audio Control Module (ACM), Satellite Digital Audio Receiver System (SDARS) module, Smart Junction Box (SJB) and the Instrument Cluster (IC) all communicate on the MS-CAN.
In the event that one 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 H: INTERMITTENT NO MS-CAN COMMUNICATION, COMMUNICATION CAN BE INTERMITTENTLY ESTABLISHED
NOTE: Various modules will set network DTCs during this test procedure. Clear DTCs from all modules after the diagnostic procedure is completed.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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H1 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 H2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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H2 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 H3.
No
CONNECT the negative battery cable. Go To Pinpoint Test I. Pinpoint Test I: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
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H3 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 H4.
No
CONNECT the negative battery cable. Go To Pinpoint Test I. Pinpoint Test I: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
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H4 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 H5.
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H5 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE ACM AND SDARS MODULE DISABLED
NOTE: When re-running the network test, the network test application must be first closed or the screen display will revert back to the prior run network test results.
- Disconnect: SJB Fuse 56 (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
If the vehicle is equipped with a SDARS module, GO to H6.
Otherwise, Go To Pinpoint Test E. Pinpoint Test E: The Audio Control Module (ACM) Does Not Respond To The Scan Tool
No
INSTALL the removed fuse. GO to H7.
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H6 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE ACM DISCONNECTED
NOTE: When re-running the network test, the network test application must be first closed or the screen display will revert back to the prior run network test results.
- Disconnect: ACM C290a.
- 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 ACM. Go To Pinpoint Test E. Pinpoint Test E: The Audio Control Module (ACM) Does Not Respond To The Scan Tool
No
CONNECT the ACM. Go To Pinpoint Test F. Pinpoint Test F: The Satellite Digital Audio Receiver System (SDARS) Module Does Not Respond To The Scan Tool
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H7 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE SJB DISABLED
NOTE: When re-running the network test, the network test application must be first closed or the screen display will revert back to the prior run network test results.
- Disconnect: Bussed Electrical Center (BEC) Fuses 59 (30A), 63 (30A) and 67 (30A).
- 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 D. Pinpoint Test D: The Smart Junction Box (SJB) Does Not Respond To The Scan Tool
No
INSTALL the removed fuses. GO to H8.
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H8 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE IC DISABLED
NOTE: When re-running the network test, the network test application must be first closed or the screen display will revert back to the prior run network test results.
- Disconnect: SJB Fuses 19 (5A) and 16 (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 fuse. GO to H9.
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H9 CHECK FOR RESTORED NETWORK COMMUNICATION WITH THE IC DISCONNECTED
- Disconnect: IC C220.
- 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 fuse. An intermittent fault is not present. Go To Pinpoint Test I. Pinpoint Test I: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
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