2007 INFINITI QX56 service

LAN-26
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
Reception item of “IPDM E/R”: On “ECM”, “OK” is indicated. IPDM-E communicates normally with ECM.
Put a check mark on the normal circuit between ECM and IPDM-E (check mark 3-b in the figure).
4. Through the above procedure, the error is detected in the TCM branch line (shaded in the figure).
NOTE:
For abbreviations, refer to LAN-37, "
Abbreviation List".
SKIB8728E

TROUBLE DIAGNOSES WORK FLOW
LAN-27
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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5. Perform the inspection for the detected error circuit. For the inspection procedure, refer to LAN-61, "Mal-
function Area Chart".
Present Error — Short Circuit —
When the symptoms listed below exist, a short circuit of the CAN communication line is a possible cause.
Received data
Error symptom• Most the units connected to the CAN communication system go into fail-safe mode or are deactivated.
Inspection procedure
SKIB8893E
Item (CONSULT-II) Indication
SELECT SYSTEM All Diag on CAN units are not indicated.
CAN DIAG SUPPORT MNTR “UNKWN” is indicated under “TRANSMIT DIAG” and most reception items.

LAN-28
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
• Refer to LAN-61, "Malfunction Area Chart".
Past Error — Open Circuit —
Review CAN communication signal chart based on information received from the interview with the customer
and on past error information from SELF-DIAG RESULTS and CAN DIAG SUPPORT MNTR.
SKIB8894E

TROUBLE DIAGNOSES WORK FLOW
LAN-29
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1. SELF-DIAG RESULTS: Inspect the control units indicating “U1000” or “U1001” on SELF-DIAG RESULTS.
2. CAN DIAG SUPPORT MNTR (with PAST): Check the CAN DIAG SUPPORT MNTR (with PAST) of units
indicating “U1000” or “U1001” on SELF-DIAG RESULTS. Draw a line on the diagnosis sheet to indicate
the possible error circuit.
NOTE:
For the details of each indication on CAN DIAG SUPPORT MNTR, refer to LAN-40, "
CAN Diagnostic Sup-
port Monitor".
a. Reception item of “ENGINE”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means ECM could not
receive the signal from ABS in the past. Draw a line between ECM and ABS (line 2-a in the figure).
SKIB8731E

LAN-30
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
b. Reception item of “METER”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means M&A could not
receive the signal from ABS in the past. Draw a line between M&A and ABS (line 2-b in the figure).
c. Reception item of “TRANSMISSION”: “VDC/TCS/ABS”, “3” is indicated in the “PAST”. This means TCM
could not receive the signal from ABS in the past. Draw a line between TCM and ABS (line 2-c in the fig-
ure).
3. CAN DIAG SUPPORT MNTR (without PAST): Check the CAN DIAG SUPPORT MNTR (without PAST) of
units indicating “U1000” or “U1001” on SELF-DIAG RESULTS. Draw a line on the diagnosis sheet to indi-
cate the possible error circuit.
NOTE:
• While an error occurred in the past according to SELF-DIAG RESULTS, it is unclear which signal is not
received. Assume that errors were detected from all reception items.
• Draw a single line among the unit and all reception items. (Work flow differs from CAN DIAG SUPPORT
MNTR (with PAST).)
a. Reception item of “EPS”: Assume that the unit could not receive the signals from ECM, ABS, and M&A.
Draw a line among EPS, ECM, ABS, and M&A (line 3-a in the figure).
SKIB8732E

TROUBLE DIAGNOSES WORK FLOW
LAN-31
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b. Reception item of “ABS”: Assume that the unit could not receive the signal from ECM. Draw a line
between ABS and ECM (line 3-b in the figure).
4. Search for the possible cause using CAN communication signal chart using information from the interview
with the customer.
NOTE:
For the details of CAN communication signal, refer to LAN-44, "
CAN Communication Signal Chart".
a. ABS warning lamp turned ON and speedometer did not move: This means that “ABS warning lamp signal”
and “Vehicle speed signal” could not communicate between M&A and ABS (4-a in the figure).
SKIB8733E

LAN-32
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSES WORK FLOW
b. The tachometer moved normally: This means that “Engine speed signal” could communicate normally
between ECM and M&A (4-b in the figure).
5. Fill out the diagnosis sheet based on information from step 4.
a. The ABS warning lamp turned ON and speedometer did not move: Assume that a possible cause is no
communication between M&A and ABS. Draw a line between M&A and ABS. (Line 5-a in the figure).
SKIB8895E

TROUBLE DIAGNOSES WORK FLOW
LAN-33
< SERVICE INFORMATION >[CAN FUNDAMENTAL]
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b. The tachometer moved normally: Put check marks between ECM and M&A. The circuit between ECM and
M&A is functioning properly (check marks 5-b in the figure).
6. The circuit which has the most amount of lines are the possible cause. Error is detected from ABS actua-
tor and electric unit (control unit) branch line (shaded in the figure).
NOTE:
For abbreviations, refer to LAN-37, "
Abbreviation List".
SKIB8735E