Pinpoint Test I: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
Communications Network
Pinpoint Tests
Pinpoint Test I: 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 1847 (WH/OG) and 1848 (PK/OG). The Smart Junction Box (SJB), the Audio Control Module (ACM), the Satellite Digital Audio Receiver System (SDARS) module and the Instrument Cluster (IC) communicate with the scan tool using the MS-CAN.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ACM
- IC
- SDARS module
- SJB
PINPOINT TEST I: 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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I1 CHECK DATA LINK CONNECTOR (DLC) PINS FOR DAMAGE
- Ignition OFF.
- Disconnect the scan tool cable from the DLC.
- Inspect DLC pins 3 and 11 for damage.
- Are DLC pins 3 and 11 OK?
Yes
GO to I2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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I2 CHECK THE MS-CAN TERMINATION RESISTANCE
- Disconnect: Negative Battery Cable.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance between 54 and 66 ohms?
Yes
GO to I3.
No
GO to I5.
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I3 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/OG), harness side and ground.
- Are the resistances greater than 1,000 ohms?
Yes
CONNECT the negative battery cable. GO to I4.
No
GO to I16.
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I4 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the DLC C251-3, circuit 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/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 H to test for an intermittent network fault condition. Pinpoint Test H: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, Communication Can Be Intermittent
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I5 CHECK THE MS-CAN TERMINATION RESISTOR
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance between 108 and 132 ohms?
Yes
GO to I6.
No
GO to I9.
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I6 CHECK THE MS-CAN TERMINATION RESISTOR WITH THE SJB DISCONNECTED
- Disconnect: SJB C2280b.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance between 108 and 132 ohms?
Yes
GO to I7.
No
GO to I8.
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I7 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DLC FOR AN OPEN
- Measure the resistance between the SJB C2280b-50, circuit 1847 (WH/OG), harness side and the DLC C251-3, circuit 1847 (WH/OG), harness side.
- Measure the resistance between the SJB C2280b-51, circuit 1848 (PK/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to I21.
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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I8 CHECK HIGH SPEED CAN CIRCUITS BETWEEN THE IC AND THE DLC FOR AN OPEN
- Disconnect: IC C220.
- Measure the resistance between the IC C220-18, circuit 1827 (WH/LG), harness side and the DLC C251-6, circuit 1827 (WH/LG), harness side.
- Measure the resistance between the IC C220-17, circuit 1828 (PK/LG), harness side and the DLC C251-14, circuit 1828 (PK/LG), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT all modules. CONNECT the negative battery cable. GO to I21.
No
REPAIR the circuit in question. CONNECT the negative battery cable. CONNECT all modules. CLEAR the DTCs. REPEAT the network test with the scan tool.
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I9 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I11.
No
GO to I10.
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I10 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR AN OPEN
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance greater than 1,000 ohms?
Yes
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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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I11 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE SJB DISCONNECTED
- Disconnect: SJB C2280b.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I12.
No
CONNECT the negative battery cable. GO to I21.
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I12 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE IC DISCONNECTED
- Disconnect: IC C220.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I13.
No
CONNECT all modules. CONNECT the negative battery cable. GO to I22.
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I13 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 I14.
No
GO to I15.
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I14 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE SDARS MODULE DISCONNECTED
- Disconnect: SDARS Module C4344.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I15.
No
CONNECT all modules. CONNECT the negative battery cable. GO to I23.
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I15 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE ACM DISCONNECTED
- Disconnect: ACM C290a.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and the DLC C251-11, circuit 1848 (PK/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 all modules. CONNECT the negative battery cable. GO to I24.
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I16 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE SJB DISCONNECTED
- Disconnect: SJB C2280b.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/OG), harness side and ground.
- Are the resistances greater than 1,000 ohms?
Yes
CONNECT the negative battery cable. GO to I21.
No
GO to I17.
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I17 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 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/OG), harness side and ground.
- Are the resistances greater than 1,000 ohms?
Yes
CONNECT all modules. CONNECT the negative battery cable. GO to I22.
No
GO to I18.
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I18 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 I19.
No
GO to I20.
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I19 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE SDARS MODULE DISCONNECTED
- Disconnect: SDARS Module C4344.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/OG), harness side and ground.
- Are the resistances greater than 1,000 ohms?
Yes
CONNECT all modules. CONNECT the negative battery cable. GO to I23.
No
GO to I20.
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I20 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE ACM DISCONNECTED
- Disconnect: SJB C290a.
- Measure the resistance between the DLC C251-3, circuit 1847 (WH/OG), harness side and ground; and between the DLC C251-11, circuit 1848 (PK/OG), harness side and ground.
- Are the resistances greater than 1,000 ohms?
Yes
CONNECT all modules. CONNECT the negative battery cable. GO to I24.
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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I21 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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I22 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. 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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I23 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. 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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I24 CHECK FOR CORRECT ACM OPERATION
- Disconnect all of the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all of 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. 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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