Q1-Q27
Communications Network
Pinpoint Tests
Pinpoint Test Q: 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
- Accessory Protocol Interface Module (APIM) (if equipped)
- Audio Control Module (ACM)
- Driver Seat Module (DSM) (if equipped)
- HVAC module (if equipped)
- Instrument Cluster (IC)
- 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)
PINPOINT TEST Q: 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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Q1 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 Q2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q2 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 Q3.
No
GO to Q5.
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Q3 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
GO to Q4.
No
GO to Q28.
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Q4 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO VOLTAGE
- Connect: Negative Battery Cable.
- 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
The CAN has tested within specifications. Go To Pinpoint Test R to diagnose the intermittent MS-CAN fault. Pinpoint Test R: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, One Or More Modules Are Not Respo
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Q5 CHECK THE MS-CAN TERMINATION RESISTOR
- 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 108 and 132 ohms?
Yes
GO to Q6.
No
GO to Q9.
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Q6 CHECK THE MS-CAN TERMINATION RESISTOR WITH THE SJB DISCONNECTED
- Disconnect: SJB C2280b.
- 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 108 and 132 ohms?
Yes
GO to Q7.
No
GO to Q8.
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Q7 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DLC FOR AN OPEN
- Measure the resistance between the SJB C2280d-16, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
- Measure the resistance between the SJB C2280d-15, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to Q54.
No
REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q8 CHECK THE MS-CAN CIRCUITS BETWEEN THE IC AND THE DLC FOR AN OPEN
- Disconnect: IC C220.
- Measure the resistance between the IC C220-4, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
- Measure the resistance between the IC C220-5, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to Q45.
No
REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q9 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER
- 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 less than 5 ohms?
Yes
GO to Q11.
No
GO to Q10.
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Q10 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR AN OPEN
- 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 greater than 10,000 ohms?
Yes
REPAIR the DLC or REPAIR the circuit in question. CONNECT the negative battery cable. VERIFY the scan tool operation on a substitute vehicle. CLEAR the DTCs. REPEAT the network test on the suspect vehicle.
No
A capacitor internal to a module may still be draining causing irregular resistance readings. WAIT 5 minutes. REPEAT the pinpoint test.
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Q11 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE IC DISCONNECTED
- Disconnect: ICC220.
- 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 less than 5 ohms?
Yes
GO to Q12.
No
CONNECT the negative battery cable. GO to Q45.
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Q12 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE ACM DISCONNECTED
- Disconnect: ACMC290b.
- 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 less than 5 ohms?
Yes
GO to Q13.
No
CONNECT the negative battery cable. GO to Q46.
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Q13 VERIFY VEHICLE EQUIPMENT - HVAC MODULE
- Inspect the vehicle for an HVAC module.
- Is the vehicle equipped with an HVAC module?
Yes
GO to Q14.
No
GO to Q15.
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Q14 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module C228a.
- 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 less than 5 ohms?
Yes
GO to Q15.
No
CONNECT the negative battery cable. GO to Q47.
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Q15 VERIFY VEHICLE EQUIPMENT - RETM
- Inspect the vehicle for an RETM.
- Is the vehicle equipped with an RETM?
Yes
GO to Q16.
No
GO to Q17.
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Q16 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE RETM DISCONNECTED
- Disconnect: RETM C9029.
- 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 less than 5 ohms?
Yes
GO to Q17.
No
CONNECT the negative battery cable. GO to Q48.
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Q17 VERIFY VEHICLE EQUIPMENT - DSM
- Inspect the vehicle for a DSM.
- Is the vehicle equipped with a DSM?
Yes
GO to Q18.
No
GO to Q19.
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Q18 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE DSM DISCONNECTED
- Disconnect: DSM C341c.
- 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 less than 5 ohms?
Yes
GO to Q19.
No
CONNECT the negative battery cable. GO to Q49.
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Q19 VERIFY VEHICLE EQUIPMENT - SDARS MODULE
- Inspect the vehicle for a SDARS module.
- Is the vehicle equipped with a SDARS module?
Yes
GO to Q20.
No
GO to Q21.
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Q20 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE SDARS MODULE DISCONNECTED
- Disconnect: SDARS C3290.
- 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 less than 5 ohms?
Yes
GO to Q21.
No
CONNECT the negative battery cable. GO to Q50.
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Q21 VERIFY VEHICLE EQUIPMENT - PRB MODULE
- Inspect the vehicle for a PRB module.
- Is the vehicle equipped with a PRB module?
Yes
GO to Q22.
No
GO to Q23.
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Q22 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE PRB MODULE DISCONNECTED
- Disconnect: PRB Module C4322b.
- 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 less than 5 ohms?
Yes
GO to Q23.
No
CONNECT the negative battery cable. GO to Q51.
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Q23 VERIFY VEHICLE EQUIPMENT - PAM
- Inspect the vehicle for a PAM.
- Is the vehicle equipped with a PAM?
Yes
GO to Q24.
No
GO to Q25.
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Q24 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE PAM DISCONNECTED
- Disconnect: PAM C4014 (Mountaineer), C3267 (Explorer Sport Trac) or C4226 (Explorer).
- 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 less than 5 ohms?
Yes
GO to Q25.
No
CONNECT the negative battery cable. GO to Q52.
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Q25 VERIFY VEHICLE EQUIPMENT - APIM
- Inspect the vehicle for an APIM.
- Is the vehicle equipped with an APIM?
Yes
GO to Q26.
No
GO to Q27.
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Q26 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE APIM DISCONNECTED
- Disconnect: APIM C3342.
- 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 less than 5 ohms?
Yes
GO to Q27.
No
CONNECT the negative battery cable.GO to Q53.
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Q27 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE SJB DISCONNECTED
- Disconnect: SJB C2280d.
- 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 less than 5 ohms?
Yes
REPAIR the circuit. CONNECT all modules. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
CONNECT the negative battery cable. GO to Q54.
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