U26-U50
Communications Network
Pinpoint Tests
Pinpoint Test U: 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
- Driver Seat Module (DSM)
- Front Controls Interface Module (FCIM)
- Front Display Interface Module (FDIM)
- HVAC module
- Instrument Cluster (IC)
- Liftgate/Trunk Module (LTM)
- Parking Aid Module (PAM)
- Rear Entertainment Module (RETM)
- Smart Junction Box (SJB)
PINPOINT TEST U: 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: 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: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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U26 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE PAM DISCONNECTED
- Disconnect: PAM C3267.
- 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 U40.
No
GO to U27.
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U27 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE ACM DISCONNECTED
- Disconnect: ACM C240c .
- 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 U41.
No
If the vehicle is equipped with an audio DSP module, GO to U28.
If the vehicle is not equipped with an audio DSP module, GO to U29.
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U28 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE AUDIO DSP MODULE DISCONNECTED
- Disconnect: Audio DSP Module C4208a.
- 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 U42.
No
GO to U29.
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U29 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE FCIM DISCONNECTED
- Disconnect: FCIM C2402 .
- 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 U43.
No
If the vehicle is equipped with an FDIM, GO to U30.
If the vehicle is not equipped with an FDIM, GO to U31.
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U30 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE FDIM DISCONNECTED
- Disconnect: FDIM C2123.
- 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 U44.
No
GO to U31.
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U31 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module C228a.
- 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 U45.
No
If the vehicle is equipped with an RETM, GO to U32.
If the vehicle is not equipped with an RETM, GO to U33.
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U32 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE RETM DISCONNECTED
- Disconnect: RETM C9029.
- 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 U46.
No
GO to U33.
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U33 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE IC DISCONNECTED
- Disconnect: IC C220.
- 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 U47.
No
If the vehicle is equipped with an LTM, GO to U34.
If the vehicle is not equipped with an LTM, GO to U35.
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U34 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE LTM DISCONNECTED
- Disconnect: LTM C4174a.
- 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 U48.
No
GO to U35.
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U35 VERIFY VEHICLE EQUIPMENT - DSM
- Verify whether the vehicle is equipped with a DSM.
- Is the vehicle equipped with a DSM?
Yes
GO to U36.
No
GO to U37.
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U36 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 the negative battery cable. GO to U49.
No
GO to U37.
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U37 VERIFY VEHICLE EQUIPMENT - APIM
- Verify whether the vehicle is equipped with an APIM.
- Is the vehicle equipped with an APIM?
Yes
GO to U38.
No
REPAIR the circuit. CONNECT all modules. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U38 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 the negative battery cable. GO to U50.
No
REPAIR the circuit. CONNECT all modules. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U39 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. 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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U40 CHECK FOR CORRECT PAM OPERATION
- Disconnect the PAM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the PAM 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 PAM. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U41 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U42 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U43 CHECK FOR CORRECT FCIM OPERATION
- Disconnect the FCIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the FCIM 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 FCIM. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U44 CHECK FOR CORRECT FDIM OPERATION
- Disconnect the FDIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the FDIM 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 FDIM. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U45 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U46 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U47 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC connector and make it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new IC. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U48 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U49 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U50 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. CONNECT all modules. 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. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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