Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Computers/Controls - CAN Communication Diagnostic Flow Chart
2011 Infiniti M56 V8-5.6L (VK56VD)SECTION Computers/Controls - CAN Communication Diagnostic Flow Chart
Classification: EL13-010
Reference: ITB13-006
Date: March 22, 2013
2005-2013 INFINITI; CAN COMMUNICATION - NETWORK DIAGNOSTIC FLOW CHART
APPLIED VEHICLES: All 2005 - 2013MY Infiniti Vehicles
SERVICE INFORMATION
This TSB is for troubleshooting of CAN Modules with "Diag-On-CAN" Diagnostics. The flow charts below are meant to troubleshoot current CAN DTCs. The flow charts are intended to diagnose one module at a time; repeat the process as needed for additional control units.
Definition of CAN Codes:
U1000 - missing ECM CAN communications not related to OBD2 system
U1000 - missing CAN communications for all other ECUs
U1001 - missing ECM CAN communications related to OBD2 system
U1002 - similar to U1000, but has a tighter timing spec to set the DTC
U1010 - Module has internal Issues
CLAIMS INFORMATION
Helpful Tips:
^ Always diagnose CAN communication codes first, U1000, U1001, U1002, U1010, then network codes, UXXXX, and then all other codes.
^ A quick method to test CAN communications is to operate the vehicles functions such as Hazards, Brakes, Tachometer, PRNDL, Speedometer, 4WD, Difflock, Seat Memory, Power Back Door or High Beams.
^ In a low voltage situation (less than 10V), modules will stop communicating at different voltages.
^ Integrated Power Distribution Module (IPDM) is a smart relay and fuse box. It powers other modules in the same way fuses and relays do.
^ CAN voltages can be checked via CONSULT.
^ Missing "Ignition 2" fuse or other high level fuses can cause CAN Diag Support Monitor to not work.
^ High level fuses such as "Ignition 1", "Ignition 2" and "Elec B" power many modules.
^ Pins/terminals can be bent and still pass visual inspection.
^ When troubleshooting a harness that has multiple inline connections, section off the harness and isolate it one portion at a time. Add a terminating resistor to the end of the harness in substitution of the terminating modules.
^ If a module has multiple connectors, disconnect one at a time.
NOTE:
120 ohm resistors may be needed to perform diagnostics.
Normal CAN Measurements
Main Types of Issues
Troubleshooting Flowchart
Flowchart A
Flowchart B
Flowchart C
Harness Incident Type
Disclaimer
Reference: ITB13-006
Date: March 22, 2013
2005-2013 INFINITI; CAN COMMUNICATION - NETWORK DIAGNOSTIC FLOW CHART
APPLIED VEHICLES: All 2005 - 2013MY Infiniti Vehicles
SERVICE INFORMATION
This TSB is for troubleshooting of CAN Modules with "Diag-On-CAN" Diagnostics. The flow charts below are meant to troubleshoot current CAN DTCs. The flow charts are intended to diagnose one module at a time; repeat the process as needed for additional control units.
Definition of CAN Codes:
U1000 - missing ECM CAN communications not related to OBD2 system
U1000 - missing CAN communications for all other ECUs
U1001 - missing ECM CAN communications related to OBD2 system
U1002 - similar to U1000, but has a tighter timing spec to set the DTC
U1010 - Module has internal Issues
CLAIMS INFORMATION
Helpful Tips:
^ Always diagnose CAN communication codes first, U1000, U1001, U1002, U1010, then network codes, UXXXX, and then all other codes.
^ A quick method to test CAN communications is to operate the vehicles functions such as Hazards, Brakes, Tachometer, PRNDL, Speedometer, 4WD, Difflock, Seat Memory, Power Back Door or High Beams.
^ In a low voltage situation (less than 10V), modules will stop communicating at different voltages.
^ Integrated Power Distribution Module (IPDM) is a smart relay and fuse box. It powers other modules in the same way fuses and relays do.
^ CAN voltages can be checked via CONSULT.
^ Missing "Ignition 2" fuse or other high level fuses can cause CAN Diag Support Monitor to not work.
^ High level fuses such as "Ignition 1", "Ignition 2" and "Elec B" power many modules.
^ Pins/terminals can be bent and still pass visual inspection.
^ When troubleshooting a harness that has multiple inline connections, section off the harness and isolate it one portion at a time. Add a terminating resistor to the end of the harness in substitution of the terminating modules.
^ If a module has multiple connectors, disconnect one at a time.
NOTE:
120 ohm resistors may be needed to perform diagnostics.
Normal CAN Measurements
Main Types of Issues
Troubleshooting Flowchart
Flowchart A
Flowchart B
Flowchart C
Harness Incident Type
Disclaimer
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.