Part 2
Communications Network
Pinpoint Tests
Pinpoint Test W: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number
Normal Operation
The Medium Speed Controller Area Network (MS-CAN) uses an unshielded twisted pair cable, circuits VDB06 (GY/OG) and VDB07 (VT/OG) provide the network connection to all modules on the network.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Audio Control Module (ACM)
- Accessory Protocol Interface Module (APIM)
- Audio Digital Signal Processing (DSP) module (if equipped)
- Audio Rear Control Unit (RCU) module (if equipped)
- Dual Climate Controlled Seat Module (DCSM) (if equipped)
- Driver Seat Module (DSM) (if equipped)
- Global Positioning System Module (GPSM)
- HVAC module (if equipped)
- Instrument Cluster (IC)
- Liftgate/Trunk Module (LTM) (if equipped)
- Parking Aid Module (PAM) (if equipped)
- Power Running Board (PRB) module (if equipped)
- Rear Entertainment Module (RETM) (if equipped)
- Satellite Digital Audio Receiver System (SDARS) module (if equipped)
- Smart Junction Box (SJB)
- Data Link Connector (DLC)
PINPOINT TEST W: NO MS-CAN COMMUNICATION, ALL MODULES ARE NOT RESPONDING
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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W39 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE AUDIO DSP MODULE DISCONNECTED
- Disconnect: Audio DSP Module C2364c.
- 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 all modules. CONNECT the negative battery cable. GO to W65.
No
GO to W40.
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W40 VERIFY VEHICLE EQUIPMENT - HVAC MODULE
- Inspect the vehicle for an HVAC module.
- Is the vehicle equipped with an HVAC module?
Yes
GO to W41.
No
GO to W42.
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W41 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module C228a (EATC) or C2357a (EMTC).
- 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 all modules. CONNECT the negative battery cable. GO to W66.
No
GO to W42.
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W42 VERIFY VEHICLE EQUIPMENT - APIM
- Inspect the vehicle for an Accessory Protocol Interface Module (APIM).
- Is the vehicle equipped with an APIM?
Yes
GO to W43.
No
GO to W44.
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W43 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE APIM DISCONNECTED
- Disconnect: APIM C3342.
- 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 all modules. CONNECT the negative battery cable. GO to W67.
No
GO to W44.
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W44 VERIFY VEHICLE EQUIPMENT - AUDIO RCU MODULE
- Inspect the vehicle for an audio Rear Control Unit (RCU) module.
- Is the vehicle equipped with an audio RCU module?
Yes
GO to W45.
No
GO to W46.
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W45 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE AUDIO RCU MODULE DISCONNECTED
- Disconnect: Audio RCU module C3077.
- 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 all modules. CONNECT the negative battery cable. GO to W68.
No
GO to W46.
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W46 VERIFY VEHICLE EQUIPMENT - RETM
- Inspect the vehicle for a Rear Entertainment Module (RETM).
- Is the vehicle equipped with an RETM?
Yes
GO to W47.
No
GO to W48.
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W47 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE RETM DISCONNECTED
- Disconnect: RETM C949.
- 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 all modules. CONNECT the negative battery cable. GO to W69.
No
GO to W48.
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W48 VERIFY VEHICLE EQUIPMENT - DSM
- Inspect the vehicle for a Driver Seat Module (DSM).
- Is the vehicle equipped with a DSM?
Yes
GO to W49.
No
GO to W50.
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W49 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE DSM DISCONNECTED
- Disconnect: DSM C341d.
- 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 all modules. CONNECT the negative battery cable. GO to W70.
No
GO to W50.
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W50 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 W51.
No
GO to W52.
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W51 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE DCSM DISCONNECTED
- Disconnect: DCSM C3265c.
- 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 all modules. CONNECT the negative battery cable. GO to W71.
No
GO to W52.
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W52 VERIFY VEHICLE EQUIPMENT - SDARS MODULE
- Inspect the vehicle for a Satellite Digital Audio Receiver System (SDARS) module.
- Is the vehicle equipped with a SDARS module?
Yes
GO to W53.
No
GO to W54.
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W53 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE SDARS MODULE DISCONNECTED
- Disconnect: SDARS Module C3290.
- 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 all modules. CONNECT the negative battery cable. GO to W72.
No
GO to W54.
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W54 VERIFY VEHICLE EQUIPMENT - PRB MODULE
- Inspect the vehicle for a PRB module.
- Is the vehicle equipped with a PRB module?
Yes
GO to W55.
No
GO to W56.
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W55 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE PRB MODULE DISCONNECTED
- Disconnect: PRB Module C3313b.
- 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 all modules. CONNECT the negative battery cable. GO to W73.
No
GO to W56.
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W56 VERIFY VEHICLE EQUIPMENT - PAM
- Inspect the vehicle for a PAM.
- Is the vehicle equipped with a PAM?
Yes
GO to W57.
No
GO to W58.
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W57 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE PAM DISCONNECTED
- Disconnect: PAM C4226 (Expedition) or C4014a (Navigator).
- 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 all modules. CONNECT the negative battery cable. GO to W74.
No
GO to W58.
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W58 VERIFY VEHICLE EQUIPMENT - GPSM
- Inspect the vehicle for a GPSM.
- Is the vehicle equipped with a GPSM?
Yes
GO to W59.
No
GO to W60.
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W59 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE GPSM DISCONNECTED
- Disconnect: GPSM C2398.
- 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
GO to W60.
No
CONNECT all modules. CONNECT the negative battery cable. GO to W76.
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W60 VERIFY VEHICLE EQUIPMENT - LTM
- Inspect the vehicle for an LTM.
- Is the vehicle equipped with an LTM?
Yes
GO to W61.
No
REPAIR the circuit in question. CONNECT all modules. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W61 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE LTM DISCONNECTED
- Disconnect: LTM C4174b.
- 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 all modules. CONNECT the negative battery cable. GO to W75.
No
REPAIR the circuit in question. CONNECT all modules. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W62 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new SJB. REFER to Body Control Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W63 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IC. REFER to Instrument Panel, Gauges and Warning Indicators. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W64 CHECK FOR CORRECT ACM OPERATION
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ACM. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W65 CHECK FOR CORRECT AUDIO DSP MODULE OPERATION
- Disconnect all the audio DSP module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the audio DSP module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new audio DSP module. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W66 CHECK FOR CORRECT HVAC MODULE OPERATION
- Disconnect all the HVAC module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the HVAC module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new HVAC module. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W67 CHECK FOR CORRECT APIM OPERATION
- Disconnect the APIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the APIM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new APIM. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W68 CHECK FOR CORRECT AUDIO RCU MODULE OPERATION
- Disconnect the audio RCU module connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the audio RCU module connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new audio RCU module. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W69 CHECK FOR CORRECT RETM OPERATION
- Disconnect the RETM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the RETM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new RETM. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W70 CHECK FOR CORRECT DSM OPERATION
- Disconnect all the DSM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DSM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new DSM. REFER to Body Control Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W71 CHECK FOR CORRECT DCSM OPERATION
- Disconnect all the DCSM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DCSM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new DCSM. REFER to Seats. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W72 CHECK FOR CORRECT SDARS MODULE OPERATION
- Disconnect the SDARS module connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the SDARS module connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new SDARS module. REFER to Accessories and Optional Equipment. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W73 CHECK FOR CORRECT PRB MODULE OPERATION
- Disconnect all the PRB module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PRB module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PRB module. REFER to Auxiliary Step / Running Board. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W74 CHECK FOR CORRECT PAM OPERATION
- Disconnect all the PAM connector(s).
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PAM connector(s) and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PAM. REFER to Collision Avoidance and Parking Assist Systems. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W75 CHECK FOR CORRECT LTM OPERATION
- Disconnect all the LTM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LTM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new LTM. REFER to Doors, Hood and Trunk. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.
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W76 CHECK FOR CORRECT GPSM OPERATION
- Disconnect: Disconnect the GPSM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DSM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new GPSM. Refer to Accessories and Optional Equipment.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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