Precautions 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. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted. 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. |
Precautions Necessary for Steering Wheel Rotation After Battery Disconnect
Note. This Procedure is applied only to models with Intelligent Key system and NVIS/IVIS (NISSAN/INFINITI VEHICLE IMMOBILIZER SYSTEM - NATS). Remove and install all control units after disconnecting both battery cables with the ignition knob in the "LOCK" position. Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work. If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NVIS/IVIS, an electrically controlled steering lock mechanism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before starting the repair operation.
EPS MOTOR
EPS motor provides the assist torque by control signal from EPS control unit.
REDUCTION GEAR
Reduction gear increases the assist torque provided from EPS motor with worm gears, and outputs to the column shaft.
EPS WARNING LAMP
Turns ON when there is a malfunction in EPS system. It indicates that fail-safe mode is engaged and enters a manual steering state (Control turning force steering wheel becomes heavy).
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF after the engine starts if system is normal.
EPS Warning Lamp Indication
| Condition | EPS warning lamp |
|---|---|
| Lamp check | Turns ON when ignition switch is turned ON. Turns OFF after engine start. |
| EPS system malfunction | ON |
| Other than above (system normal) | OFF |
EPS WARNING LAMP CHART
Scheme 13
TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT
Data are reference values and are measured between each terminal and ground.
| Terminal | Wire color | Item | Condition | Data (Approx.) | |
|---|---|---|---|---|---|
| 4 | V | Torque sensor sub | Engine running | Steering wheel: Not steering (There in no steering force) | 2.5 V |
| Steering wheel: Steering | 1.7 V - 3.3 V (The value is changed according to steering left or right) | ||||
| 5 | BR | Torque sensor power supply | Ignition switch: ON | 8 V | |
| Ignition switch: OFF | 0 V | ||||
| 6 | G | Torque sensor main | Engine running | Steering wheel: Not steering (There is no steering force) | 2.5 V |
| Steering wheel: Steering | 1.7 V - 3.3 V (The value is changed according to steering left or right) | ||||
| 7 | R | Torque sensor ground | Always | 0 V | |
| 9 | L | CAN-H | |||
| 10 | O | Power supply | Ignition switch: ON | Battery voltage | |
| Ignition switch: OFF | 0 V | ||||
| 16 | P | CAN-L | |||
| 17 | R | Power supply (Memory back-up) | Ignition switch: ON | Battery voltage | |
| Ignition switch: OFF | Battery voltage | ||||
| 18 | B | Ground | Always | 0 V | |
| 19 | Motor (+) | ||||
| 20 | Motor (-) | ||||
TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT
| CAUTION | When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals. |
FUNCTION
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
| Diagnostic test mode | Function |
|---|---|
| SELF-DIAGNOSTIC RESULTS | Self-diagnostic results can be read and erased quickly. |
| DATA MONITOR | Input/Output data in the EPS control unit can be read. |
| CAN diagnostic support monitor | The results of transmit/receive diagnosis of CAN communication can be read. |
| ECU part number | EPS control unit part number can be read. |
DIAGNOSTIC TEST MODES CHART
Display Item List
| Item (CONSULT-II screen terms) | Diagnostic item is detected when.... | Refer To |
|---|---|---|
| BATTERY VOLT [C1601] | When the power supply malfunction supplied to EPS control unit is detected. | " DTC C1601 BATTERY VOLT " |
| TORQUE SENSOR [C1604] | When the torque sensor malfunction assembled in steering column assembly is detected. | " DTC C1604 TORQUE SENSOR " |
| EPS MOTOR [C1606] | When the motor driver malfunction of EPS control unit or EPS motor malfunction is detected. | " DTC C1606 EPS MOTOR " |
| EEPROM [C1607] | When the memory (EEPROM) system malfunction is detected in EPS control unit. | " DTC C1607 EEPROM " |
| CONTROL UNIT [C1608] | When the internal malfunction is detected in EPS control unit. | " DTC C1608 CONTROL UNIT " |
| CAN VHCL SPEED [C1609] | When the malfunction is detected in vehicle speed signal received with CAN communication. | " DTC C1609 CAN VHCL SPEED " |
| CAN ENG RPM [C1610] | When the malfunction is detected in engine status signal received with CAN communication. | " DTC C1610 CAN ENG RPM " |
| CAN COMM CIRCUIT [U1000] | When EPS control unit is not transmitting or receiving CAN communication signal 2 seconds or more. | " DTC U1000 CAN COMM CIRCUIT " |
| NO DTC IS DETECTED. FURTHER TESTING MAY BE REQUIRED. | No NG item has been detected. |
DISPLAY ITEM LIST
| CAUTION | If "CAN COMM CIRCUIT [U1000]" is displayed with other DTCs, first perform the trouble diagnosis for CAN communication line. |
| Monitor item (Unit) | Remarks |
|---|---|
| MOTOR VOL (V) | Power supply voltage for EPS control unit is displayed |
| TORQUE SENSOR (Nm) | Steering wheel turning force detected by torque sensor is displayed |
| MOTOR SIG (A) | Current commanded value to EPS motor is displayed |
| MOTOR CURRENT (A) | Current value consumed by EPS motor is displayed |
| VEHICLE SPEED (km/h) or (mph) | Vehicle speed is displayed from vehicle speed signal with CAN communication |
| WARNING LAMP (ON/OFF) | EPS warning lamp control status is displayed |
| DERATING STAT (ON/OFF) | Protect overload status is displayed |
| ENGINE STATUS (STOP/RUN) | Engine speed is displayed from engine status signal with CAN communication |
DISPLAY ITEM LIST
EPS CONTROL UNIT PART NUMBER
Display a part number of EPS control unit carried by a vehicle.
CONSULT-III REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
| Monitor item (Unit) | Content | Condition | Display value |
|---|---|---|---|
| MOTOR VOL (V) | Power supply voltage for EPS control unit | Ignition switch: ON | Battery voltage |
DATA REFERENCE VALUE CHART
Refer to " TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT ".
Scheme 14
Scheme 15
Scheme 16
- CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT Turn ignition switch "OFF". Disconnect EPS control unit harness connector. Turn ignition switch "ON". (Do not start engine.) Check voltage between EPS control unit harness connector (A) terminals and ground. TERMINALS VOLTAGE CHART Connector Terminal Voltage M53 10 - Ground Battery voltage M54 17 - Ground Battery voltage Turn ignition switch "OFF". Check voltage between EPS control unit harness connector (A) terminals and ground. TERMINALS VOLTAGE CHART Connector Terminal Voltage M53 10 - Ground Approx. 0 V M54 17 - Ground Battery voltage Connect EPS control unit harness connector. OK or NG OK >> GO TO 2. NG >> Check the following. If any items are damaged, repair or replace damaged parts. 60 A fusible link (No. m , located in the fuse and fusible link block). Refer to " «POWER SUPPLY ROUTING CIRCUIT»(ref-337618-S12320956552009080600000) ". 10 A fuses (No. 2, located in the fuse block). Refer to " «POWER SUPPLY ROUTING CIRCUIT»(ref-337618-S12320956552009080600000) ". Harness for short or open between battery and EPS control unit harness connector M54 terminal 17. Harness for short or open between ignition switch and EPS control unit harness connector M53 terminal 10.
- CHECK EPS CONTROL UNIT GROUND CIRCUIT Turn ignition switch "OFF". Disconnect EPS control unit harness connector. Check continuity between EPS control unit harness connector (A) terminal and ground. TERMINALS CONTINUITY CHART Connector Terminal Continuity M54 18 Yes Also check harness for short to power. Connect EPS control unit harness connector. OK or NG OK >> GO TO 3. NG >> Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK DTC Start engine. Does EPS warning lamp turn OFF? YES >> INSPECTION END NO >> Perform self-diagnosis, repair or replace damaged parts. Refer to " «SELF-DIAG RESULTS MODE»(ref-337639-S25531247662009080600000) ".
Data are reference value.
| Monitor item (Unit) | Content | Condition | Display value | |
|---|---|---|---|---|
| TORQUE SENSOR (Nm) | Steering wheel turning force | Engine running | Steering wheel: Not steering (There is no steering force) | 0.00 Nm |
| Steering wheel: Steering | 0 - 8.19 Nm (1) (The value is changed according to steering left or right) | |||
| (1) In the front of the value"L" is displayed at steering left and "R" is displayed at steering right. | ||||
| (1) | In the front of the value"L" is displayed at steering left and "R" is displayed at steering right. |
DATA REFERENCE VALUE CHART
Refer to " TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT ".
Scheme 17
- CHECK TORQUE SENSOR SIGNAL With CONSULT-III Start engine. Select "DATA MONITOR" mode for "EPS" with CONSULT-III. Check the value of "TORQUE SENSOR". Refer to " «SPECIFICATIONS WITH CONSULT-III»(ref-337639-S08191483022009080600000) ". Without CONSULT-III Start engine. Check voltage between EPS control unit harness connector M53 terminals 4, 5, 6, 7 and ground. Refer to " «TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT»(ref-337639-S30847268552009080600000) ". OK or NG OK >> GO TO 3 . NG >> GO TO 2.
- CHECK HARNESS AND CONNECTOR Turn ignition switch "OFF". Disconnect EPS control unit harness connector and torque sensor harness connector. Check continuity between EPS control unit harness connector (A) M53 terminals 4, 5, 6, 7 and torque sensor harness connector (B) M63 terminals 1, 2, 3, 4. TERMINALS CONTINUITY CHART Terminal Continuity 4 - 3 Yes 5 - 2 6 - 1 7 - 4 Also check harness for short to ground and short to power. Connect EPS control unit harness connector and torque sensor harness connector. OK or NG OK >> GO TO 3. NG >> Repair or replace damaged parts.
- CHECK EPS CONTROL UNIT Check EPS control unit input/output signal. Refer to " «EPS CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES»(ref-337639-S38338485312009080600000) ". OK or NG OK >> GO TO 4. NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
- CHECK DTC Perform the self-diagnosis, after driving the vehicle for a while. OK or NG OK >> INSPECTION END NG >> Torque sensor is malfunctioning. Replace steering column assembly. Refer to " «REMOVAL AND INSTALLATION»(ref-337621-S42121218432009080600000) ".
Data are reference value.
| Monitor item (Unit) | Content | Condition | Display value | |
|---|---|---|---|---|
| MOTOR SIG (A) | Command current to EPS motor | Engine running | Steering wheel: Not steering (There is no steering force) | 0.00 A |
| Steering wheel: Steering | 0 - 65.00 A (The value is changed according to steering left or right) | |||
| MOTOR CURRENT (A) | Consumption current of EPS motor | Engine running | Steering wheel: Not steering (There is no steering force) | 0.00 A |
| Steering wheel: Steering | 0 - 65.00 A (1) (The value is changed according to steering left or right) | |||
| (1) Almost in accordance with the value of "MOTOR SIG". It is not a malfunction though these values are not accorded when steering quickly. | ||||
| (1) | Almost in accordance with the value of "MOTOR SIG". It is not a malfunction though these values are not accorded when steering quickly. |
DATA REFERENCE VALUE CHART
Refer to " TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT ".
Scheme 18
- CHECK EPS MOTOR SIGNAL With CONSULT-III Start engine. Select "DATA MONITOR" mode for "EPS" with CONSULT-III. Check the values of "MOTOR SIG" and "MOTOR CURRENT". Refer to " «SPECIFICATIONS WITH CONSULT-III»(ref-337639-S08191483022009080600000) ". OK or NG OK >> GO TO 3 . NG >> GO TO 2.
- CHECK EPS MOTOR Turn ignition switch "OFF". Disconnect EPS control unit harness connector. Check resistance between EPS control unit harness connector (A) terminals. TERMINALS RESISTANCE CHART Connector Terminal Resistance M60 19 - 20 Approx. 0.1 ohms or less Connect EPS control unit harness connector. OK or NG OK >> GO TO 3. NG >> EPS motor is malfunctioning. Replace steering column assembly. Refer to " «REMOVAL AND INSTALLATION»(ref-337621-S42121218432009080600000) ".
- CHECK EPS CONTROL UNIT Check EPS control unit input/output signal. Refer to " «EPS CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES»(ref-337639-S38338485312009080600000) ". OK or NG OK >> GO TO 4. NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
- CHECK DTC Perform the self-diagnosis, after driving the vehicle for a while. OK or NG OK >> INSPECTION END NG >> GO TO 3.
Da0ta are reference value.
| Monitor item (Unit) | Content | Condition | Display value |
|---|---|---|---|
| VEHICLE SPEED (km/h) or (mph) | Vehicle speed | Vehicle stopped | 0 km/h (0 mph) |
| While driving | Approximately equal to the indication on speedometer (Inside of ±10%) | ||
| *: It is not a malfunction, though it might not be corresponding just after ignition switch is turned ON. | |||
DATA REFERENCE VALUE CHART
Data are reference value.
| Monitor item (Unit) | Content | Condition | Display value |
|---|---|---|---|
| ENGINE STATUS (RUN/STOP) | Engine status | Engine stopped (Engine speed: Less than 400 RPM) | STOP |
| Engine running (Engine speed: 400 RPM or more) | RUN |
DATA REFERENCE VALUE CHART
- Turn ignition switch "OFF".
- Disconnect EPS control unit harness connector.
- Check resistance between EPS control unit harness connector (A) terminals. TERMINALS RESISTANCE CHART Connector Terminal Resistance M60 19 - 20 Approx. 0.1 ohms or less
- If NG, replace the steering column assembly. Refer to " «REMOVAL AND INSTALLATION»(ref-337621-S42121218432009080600000) ".