Classification:

Reference:

EL13-007D

Date:

NTB13-027D

May 20, 2024

CAN COMMUNICATION – NETWORK
DIAGNOSTIC FLOW CHART
This bulletin has been amended. See AMENDMENT HISTORY on the last page.
Please discard previous versions of this bulletin.

APPLIED VEHICLES:

All 2005-2024 Nissan vehicles except:
 2023-2024 ARIYA (FE0)
 2022-2024 Pathfinder (R53)
 2021-2024 Rogue (T33)
 2020-2024 Sentra (B18)

SERVICE INFORMATION
This TSB is for troubleshooting of CAN Modules with “Diag-On-CAN” Diagnostics. The flow
charts included 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

Nissan Bulletins are intended for use by qualified technicians, not 'do-it-yourselfers'. Qualified technicians are
properly trained individuals who have the equipment, tools, safety instruction, and know-how to do a job
properly and safely. NOTE: If you believe that a described condition may apply to a particular vehicle, DO
NOT assume that it does. See your Nissan dealer to determine if this applies to your vehicle.
1/8

Helpful Tips:
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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 vehicle’s 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.

HINT: 120 ohm resistors may be needed to perform diagnostics.

Normal CAN Measurements
CAN
Normal Resistance measurement
* kΩ = kilo Ohms, OC = open circuit

HI-LO
60Ω

HI-GND
kΩ-OC *

LO-GND
kΩ-OC *

Main Types of Issues:
Harness Issue

Module Issue

Harness & Module Issue

DO NOT REPLACE ANY COMPONENTS UNLESS IT IS SUPPORTED BY DIAGNOSIS
HINT: Use legend below for flow charts on pages 3-6 and Table A on page 7.
OC=Open Circuit; SC=Short Circuit; H=High; L=Low; Mid=Middle; Term=Terminating;
V=voltage; DLC=data link connector

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NTB13-027D

Troubleshooting Flowchart
START

Yes

Does CONSULT list all DiagOn-CAN Modules all the time?

No

CAN Bus wires and
termination resistance are
OK.
Cycle Ignition

A

Go to
on
page 4

E

What current CAN DTCs are
shown in CONSULT?
HINT: If no current DTCs are shown,
this TSB does not apply. Reference
the Electronic Service Manual (ESM)
for diagnosis of intermittent issues.

U1000, U1001, U1002,
and other CAN related
DTCs UXXXX

Check the following items:
U1010

Replace the
module that
sets U1010.



Module was not connected



Module has internal issue



Module is not installed



Wrong Part Number



Module is not programmed



Wrong configuration

B

Go to
on
page 6

End Diagnosis 1
(See CLAIMS
INFORMATION)

3/8

NTB13-027D

A
No, it’s
intermittent

Yes, CAN module(s)
is always missing

Does CONSULT not communicate with
Diag on CAN module(s)?

Does CAN Bus
resistance = 60Ω?

Check battery,
ignition and fuse
powering DLC.

Yes
Is missing module
a terminator
module?

No
Check
terminator
module
connection

No

Check the following items:
 Confirm vehicle
battery voltage

Yes

Check: power feeds,
battery, ignition,
fuses, relay, other
module for bent pin,
swapped pins,
backed out pins,
harness continuity.

 Check shorting pin
 Check to see if inline
connectors are
swapped
 Check to see if
module was not
connected

Check DLC
ground

Check grounds

Fix the issue

Re-run diagnosis
to verify issue is
resolved.
Measure Voltage/Resistance,
match to type in table on
page 7.

Confirm good
connection at
front and back
of DLC.
Was DLC OK?
No

Yes
CAN Bus is
shorted or CAN
circuits are
swapped
Measure
Voltage/Resistance, match to
type in chart on
page 7.
Fix the issue

C

Go to
on
page 5

End Diagnosis 3
(See CLAIMS
INFORMATION)

Re-run
diagnosis to
verify issue is
resolved.

End Diagnosis 2
(See CLAIMS
INFORMATION)
4/8

NTB13-027D

No

C: Does CAN BUS have open
circuit?

Disconnect all
Diag-On-CAN
modules

Yes

D

Go to
on
page 6

Replace each
terminating module
with 120Ω resistor

Measure Voltage
from CAN H to L

Does Voltage = 0?

No

Yes

CAN Bus is shorted
to intermittent signal

Connect one (1) DiagON-CAN Module.
Fix the issue

Check module diagnosis
via CONSULT.

Was communication
intermittent?

Yes

Replace the
module

No
Have all modules
been added?
No

Re-run diagnosis to
verify issue resolved.
Yes

E

Go to
on
page 3

5/8

End Diagnosis 4
(See CLAIMS
INFORMATION)

NTB13-027D

B
Yes
Was the issue fixed?
End Diagnosis 2
(See CLAIMS
INFORMATION)

No
Disconnect the module setting the
CAN DTC.
Run harness continuity
check on module under
fault for CAN, Power and
Ground Circuits.

Yes

Does harness pass
continuity check?

D
No

There is a Wire
Harness issue