Nissan Altima HL32 Hybrid. Manual - part 775

LAN-54

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[HEV SYSTEM CAN]

DIAGNOSIS AND REPAIR WORKFLOW

For abbreviations, refer to 

LAN-50, "Abbreviation List"

.

DETECT THE ROOT CAUSE

Description

To detect the root cause of HEV SYSTEM CAN, check for short circuit first. When there is no short circuit,

check for open circuit.

Short Circuit

Check for short circuit, and DLC branch line open circuit.

When the symptoms listed below exist, a short circuit of the HEV SYSTEM CAN communication line or control

unit is a possible cause.

Received data

• *1: Hybrid vehicle control ECU may display one or more DTCs (INF code) listed as follows; U0100 (211), U0100 (212), U0100 (530).
• *2: Hybrid vehicle control ECU may display one or more DTCs (INF code) listed as follows; U0129 (220), U0129 (222), U0129 (528).
• *3: Hybrid vehicle control ECU may display one or more DTCs (INF code) listed as follows; U0131 (433), U0131 (434).

Error symptom

• Most the units connected to the HEV SYSTEM CAN go into fail-safe mode or are deactivated.

Inspection procedure

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Item (CONSULT-III)

Indication

The printed or saved All DTC Reading

• The items of EPS and ABS are not displayed.
• U0129, U0293, U1020 and U1022 are displayed as the ENGINE items.
• U0100

*1

, U0129

*2

 and U0131

*3

 are displayed as the HYBRID SYSTEM items.

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DIAGNOSIS AND REPAIR WORKFLOW

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[HEV SYSTEM CAN]

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• Refer to 

LAN-68, "Short Circuit"

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NOTE:

DLC branch line circuit can be open when the following conditions are satisfied as All DTC Reading result;

• The DTCs related to HEV SYSTEM CAN are not displayed as ENGINE or HYBRID SYSTEM item.

• The items of EPS and ABS are not displayed.

For the DLC branch line circuit inspection procedure, refer to 

LAN-68, "Branch Line"

.

Open Circuit

Draw a line on the diagnosis sheet to indicate the possible cause. Narrow the search.

NOTE:

• Color-code when drawing lines.

• Do not draw a line onto a existing line.

• When the root cause appears to be a branch line, be sure to check the control unit as well as the communi-

cation line.

1. Check each item on the printed or saved All DTC Reading. Draw a line on the diagnosis sheet to indicate

the error circuit. Refer to 

LAN-59, "DTC Related to HEV SYSTEM CAN List"

.

a. Reception item of “HYBRID SYSTEM”:
i.

“U0100:LOST COMM [ECM]:211”, “U0100:LOST COMM [ECM]:212” and “U0100:LOST COMM

[ECM]:530” are indicated. This means HV ECU cannot receive the signal from ECM. Draw a line to indi-

cate an error between HV ECU and ECM (line 1-a-i in the figure below). 

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[HEV SYSTEM CAN]

DIAGNOSIS AND REPAIR WORKFLOW

ii.

“U0131:LOST COMM [EPS]:433” and “U0131:LOST COMM [EPS]:434” are indicated. This means HV

ECU cannot receive the signal from EPS. Draw a line to indicate an error between HV ECU and EPS (line

1-a-ii in the figure below).

b. Reception item of “ENGINE”:
i.

“U0293” and “U1020” are indicated. This means ECM cannot receive the signal from HV ECU. Draw a line

to indicate an error between ECM and HV ECU (line 1-b-i in the figure below).

JPMIA0254GB

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DIAGNOSIS AND REPAIR WORKFLOW

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[HEV SYSTEM CAN]

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ii.

“U0129” and “U1022” are indicated. This means ECM cannot receive the signal from ABS. Draw a line to

indicate an error between ECM and ABS (line 1-b-ii in the figure below).

2. Based on information received from the printed or saved All DTC Reading, place a check mark on the

known good HEV SYSTEM CAN communication line between ECM and HV ECU.

a. Through the previous procedure, the circuit between EPS splice and ABS splice has the most amount of

lines (shade 2-a in the figure below).

b. Place a check mark on the known good lines to establish the error circuit.

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