Condition of Error Detection
"U1000" or "U1001" is indicated on SELF-DIAG RESULTS on CONSULT-III if CAN communication signal is not transmitted or received between units for 2 seconds or more.
CAN COMMUNICATION SYSTEM ERROR
- CAN communication line open (CAN-H, CAN-L, or both)
- CAN communication line short (ground, between CAN communication lines, other harnesses)
- Error of CAN communication control circuit of the unit connected to CAN communication line
WHEN "U1000" OR "U1001" IS INDICATED EVEN THOUGH CAN COMMUNICATION SYSTEM IS NORMAL
- Removal/installation of parts: Error may be detected when removing and installing CAN communication unit and related parts while turning the ignition switch ON. (A DTC except for CAN communication may be detected.)
- Fuse blown out (removed): CAN communication of the unit may cease.
- Voltage drop: Error may be detected if voltage drops due to discharged battery when turning the ignition switch ON (Depending on the control unit which carries out CAN communication).
- Error may be detected if the power supply circuit of the control unit, which carries out CAN communication, malfunctions (Depending on the control unit which carries out CAN communication).
- Error may be detected if reprogramming is not completed normally. NOTE: CAN communication system is normal if "U1000" or "U1001" is indicated on SELF-DIAG RESULTS of CONSULT-III under the above conditions. Erase the memory of the self-diagnosis of each unit.
ERROR EXAMPLE
Note. Each vehicle differs in symptom of each unit under fail-safe mode and CAN communication line wiring. Refer to " ABBREVIATION LIST " for the unit abbreviation.
Example: TCM branch line open circuit
Scheme 13
| Unit name | Symptom |
|---|---|
| ECM | Engine torque limiting is affected, and shift harshness increases. |
| BCM | Reverse warning chime does not sound. |
| EPS control unit | Normal operation. |
| Combination meter | Shift position indicator and OD OFF indicator turn OFF. Warning lamps turn ON. |
| ABS actuator and electric unit (control unit) | Normal operation. |
| TCM | No impact on operation. |
| IPDM E/R | Normal operation. |
SYMPTOM CHART
Example: Data link connector branch line open circuit
Scheme 14
| Unit name | Symptom |
|---|---|
| ECM | Normal operation. |
| BCM | |
| EPS control unit | |
| Combination meter | |
| ABS actuator and electric unit (control unit) | |
| TCM | |
| IPDM E/R |
SYMPTOM CHART
Note. When data link connector branch line is open, transmission and reception of CAN communication signals are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit. The model (all units on CAN communication system are Diag on CAN) cannot perform CAN diagnosis with CONSULT-III if the following error occurs. The error is judged by the symptom.
| Error | Difference of symptom |
|---|---|
| Data link connector branch line open circuit | Normal operation. |
| CAN-H, CAN-L harness short-circuit | Most of the units which are connected to the CAN communication system enter fail-safe mode or are deactivated. |
SYMPTOM CHART
Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Control Unit) Open Circuit
Scheme 15
| Unit name | Symptom |
|---|---|
| ECM | Engine torque limiting is affected, and shift harshness increases. |
| BCM | Reverse warning chime does not sound. The front wiper moves under continuous operation mode even though the front wiper switch being in the intermittent position. |
| EPS control unit | The steering effort increases. |
| Combination meter | The shift position indicator and OD OFF indicator turn OFF. The speedometer is inoperative. The odo/trip meter stops. |
| ABS actuator and electric unit (control unit) | Normal operation. |
| TCM | No impact on operation. |
| IPDM E/R | When the ignition switch is ON, The headlamps (Lo) turn ON. The cooling fan continues to rotate. |
SYMPTOM CHART
Example: CAN-H, CAN-L Harness Short Circuit
Scheme 16
| Unit name | Symptom |
|---|---|
| ECM | Engine torque limiting is affected, and shift harshness increases. Engine speed drops. |
| BCM | Reverse warning chime does not sound. The front wiper moves under continuous operation mode even though the front wiper switch being in the intermittent position. The room lamp does not turn ON. The engine does not start (if an error or malfunction occurs while turning the ignition switch OFF.) The steering lock does not release (if an error or malfunction occurs while turning the ignition switch OFF.) |
| EPS control unit | The steering effort increases. |
| Combination meter | The tachometer and the speedometer do not move. Warning lamps turn ON. Indicator lamps do not turn ON. |
| ABS actuator and electric unit (control unit) | Normal operation. |
| TCM | No impact on operation. |
| IPDM E/R | When the ignition switch is ON, The headlamps (Lo) turn ON. The cooling fan continues to rotate. |
SYMPTOM CHART
MONITOR ITEM (CONSULT-III)
Example: CAN DIAG SUPPORT MNTR indication
Scheme 17
Without PAST
| Item | PRSNT | Description |
|---|---|---|
| Initial diagnosis | OK | Normal at present |
| NG | Control unit error (Except for some control units) | |
| Transmission diagnosis | OK | Normal at present |
| UNKWN | Unable to transmit signals for 2 seconds or more. | |
| Diagnosis not performed | ||
| Control unit name (Reception diagnosis) | OK | Normal at present |
| UNKWN | Unable to receive signals for 2 seconds or more. | |
| Diagnosis not performed | ||
| No control unit for receiving signals. (No applicable optional parts) |
ITEM DESCRIPTION CHART
With PAST
| Item | PRSNT | PAST | Description |
|---|---|---|---|
| Transmission diagnosis | OK | OK | Normal at present and in the past |
| 1 - 39 | Normal at present, but unable to transmit signals for 2 seconds or more in the past. (The number indicates the number of ignition switch cycles from OFF to ON.) | ||
| UNKWN | 0 | Unable to transmit signals for 2 seconds or more at present. | |
| Control unit name (Reception diagnosis) | OK | OK | Normal at present and in the past |
| 1 - 39 | Normal at present, but unable to receive signals for 2 seconds or more in the past. (The number indicates the number of ignition switch cycles from OFF to ON.) | ||
| UNKWN | 0 | Unable to receive signals for 2 seconds or more at present. | |
| Diagnosis not performed. | |||
| No control unit for receiving signals. (No applicable optional parts) |
ITEM DESCRIPTION CHART
How to Use CAN Communication Signal Chart
The CAN communication signal chart lists the signals needed for trouble diagnosis. It is useful for detecting the root cause by finding a signal related to the symptom, and by checking transmission and reception unit.
Scheme 18
Scheme 19
CREATE INTERVIEW SHEET
Fill out the symptom described by the customer, vehicle condition, and CAN system type on the interview sheet.
Interview Sheet (Example)
Scheme 20
DETECT THE ROOT CAUSE
CAN diagnosis function of CONSULT-III detects the root cause.
Caution
- This service information describes information peculiar to a vehicle and inspection procedures.
- For trouble diagnosis procedure, refer to " «TROUBLE DIAGNOSIS PROCEDURE»(ref-337619-S02955348912009080600000) ".
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER"
The Supplemental Restraint System such as "AIR BAG" and "SEAT BELT PRE-TENSIONER", used along with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collision. Information necessary to service the system safely is included in the SUPPLEMENTAL RESTRAINT SYSTEM and SEAT BELTS articles.
| WARNING | To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in the event of a collision which would result in air bag inflation, all maintenance must be performed by an authorized NISSAN/INFINITI dealer. Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag Module, see the " SUPPLEMENTAL RESTRAINT SYSTEM " article. Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this article. SRS wiring harnesses can be identified by yellow and/or orange harnesses or harness connectors. |
CAN Communication Signal Chart
Refer to " HOW TO USE CAN COMMUNICATION SIGNAL CHART " for how to use CAN communication signal chart.
Note. Refer to " ABBREVIATION LIST " for the abbreviations of the connecting units.
Scheme 21
Scheme 22
Note. CAN data of the air bag diagnosis sensor unit is not used by usual service work, thus it is omitted.
Scheme 23
Scheme 24
Scheme 25
Scheme 26
Main Line
| Malfunction Area | Refer To |
|---|---|
| Main line between data link connector and ABS actuator and electric unit (control unit) | " DIAGNOSIS PROCEDURE " |
| Main line between data link connector and TCM | " DIAGNOSIS PROCEDURE " |
MALFUNCTION AREA CHART - MAIN LINE
Branch Line
| Malfunction Area | Refer To |
|---|---|
| ECM branch line circuit | " DIAGNOSIS PROCEDURE " |
| BCM branch line circuit | " DIAGNOSIS PROCEDURE " |
| Data link connector branch line circuit | " DIAGNOSIS PROCEDURE " |
| EPS control unit branch line circuit | " DIAGNOSIS PROCEDURE " |
| Intelligent Key unit branch line circuit | " DIAGNOSIS PROCEDURE " |
| Combination meter branch line circuit | " DIAGNOSIS PROCEDURE " |
| ABS actuator and electric unit (control unit) branch line circuit | " DIAGNOSIS PROCEDURE " |
| TCM branch line circuit | " DIAGNOSIS PROCEDURE " |
| IPDM E/R branch line circuit | " DIAGNOSIS PROCEDURE " |
MALFUNCTION AREA CHART - BRANCH LINE
Short Circuit
| Malfunction Area | Refer To |
|---|---|
| CAN communication circuit | " DIAGNOSIS PROCEDURE " |
MALFUNCTION AREA CHART - SHORT CIRCUIT