Pinpoint Test U: No Medium Speed Controller Area Network (MS-CAN) Communication, All Modules Are Not Responding
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). The smart junction box (SJB), the HVAC module, the Audio Control Module (ACM), the Driver Seat Module (DSM), the Rear Entertainment Module (RETM), the Satellite Digital Audio Receiver System (SDARS) module, the Liftgate/Trunk Module (LTM), the Accessory Protocol Interface Module (APIM) and the Instrument Cluster (IC) all communicate on the MS-CAN.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ACM
- APIM
- DSM
- RETM
- HVAC module
- IC
- LTM
- SDARS module
- SJB
PINPOINT TEST U: 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
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U1 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 U2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U2 CHECK THE MS-CAN TERMINATION RESISTANCE
- Ignition OFF.
- NOTE: Failure to disconnect the battery will result in false resistance readings.
- Disconnect the battery ground 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 U3.
No
GO to U5.
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U3 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 U4.
No
If the vehicle is equipped with a DSM, GO to U20.
Otherwise, GO to U21.
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U4 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO VOLTAGE
- Connect the battery ground 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 in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The CAN has tested within specifications. Go To Pinpoint Test T to test for an intermittent network fault condition. Pinpoint Test T: Intermittent No Medium Speed Controller Area Network (MS-CAN) Communication, Communication Can Be Intermittent
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U5 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 U6.
No
GO to U9.
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U6 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 U7.
No
GO to U8.
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U7 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DLC FOR AN OPEN
- Measure the resistance between the SJB C2280b-37, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
- Measure the resistance between the SJB C2280b-38, 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
GO to U30.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U8 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
GO to U36.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U9 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
If the vehicle is equipped with a DSM, GO to U11.
Otherwise, GO to U12.
No
GO to U10.
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U10 CHECK THE MS-CAN CIRCUITS FOR AN OPEN AT THE DLC
- 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 all modules. 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 network test with the scan tool.
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U11 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE DSM DISCONNECTED
- Disconnect: DSM C341d.
- 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 U10.
No
CONNECT the battery ground cable. GO to U27.
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U12 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 VDB06 (GY/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
If the vehicle is equipped with a RETM, GO to U13.
Otherwise, GO to U14.
No
CONNECT the battery ground cable. GO to U30.
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U13 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 U14.
No
CONNECT the battery ground cable. GO to U31.
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U14 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module - EATC C228a or HVAC Module - EMTC C2357a.
- 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
If the vehicle is equipped with a SDARS module, GO to U15.
Otherwise, GO to U16.
No
CONNECT the battery ground cable. GO to U32.
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U15 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 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 U16.
No
CONNECT the battery ground cable. GO to U33.
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U16 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE ACM DISCONNECTED
- Disconnect: ACM C240c.
- 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
If the vehicle is equipped with a LTM, GO to U17.
Otherwise, GO to U18.
No
CONNECT the battery ground cable. GO to U34.
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U17 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TOGETHER WITH THE LTM DISCONNECTED
- Disconnect: LTM C4174a.
- 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 U18.
No
CONNECT the battery ground cable. GO to U35.
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U18 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 VDB06 (GY/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
If the vehicle is equipped with an APIM, GO to U19.
Otherwise, REPAIR the circuit in question. CONNECT all modules. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
CONNECT the battery ground cable. GO to U36.
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U19 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
REPAIR the circuit in question. CONNECT all modules. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
CONNECT the battery ground cable. GO to U37.
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U20 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 battery ground cable. GO to U29.
No
GO to U21.
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U21 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 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 battery ground cable. GO to U30.
No
If the vehicle is equipped with a RETM, GO to U22.
Otherwise, GO to U23.
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U22 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 battery ground cable. GO to U31.
No
GO to U23.
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U23 CHECK THE MS-CAN (+) AND MS-CAN (-) CIRCUITS FOR A SHORT TO GROUND WITH THE HVAC MODULE DISCONNECTED
- Disconnect: HVAC Module - EATC C228a or HVAC Module - EMTC C2357a.
- 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 battery ground cable. GO to U32.
No
If the vehicle is equipped with a SDARS module, GO to U24.
Otherwise, GO to U25.
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U24 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 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 battery ground cable. GO to U33.
No
GO to U25.
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U25 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 battery ground cable. GO to U34.
No
If the vehicle is equipped with a LTM, GO to U26.
Otherwise, GO to U27.
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U26 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 battery ground cable. GO to U35.
No
GO to U27.
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U27 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 battery ground cable. GO to U36.
No
If the vehicle is equipped with an APIM, GO to U28.
Otherwise, REPAIR the circuit in question. CONNECT all modules. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U28 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
GO to U37.
No
REPAIR the circuit in question. CONNECT all modules. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U29 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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U30 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. 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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U31 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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U32 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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U33 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. 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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U34 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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U35 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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U36 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. 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. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U37 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. CLEAR the DTCs. REPEAT the network test with the scan tool.
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