EPS system
EPS SYSTEM : System Description
SYSTEM DIAGRAM

DESCRIPTION
EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.
In case of a malfunction in the electrical system, the fail-safe function stops output signals to the EPS motor. Refer to STC-9, "EPS SYSTEM : Fail-Safe".
EPS control unit decreases the output signal to EPS motor while extremely using the power steering function (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection control). Refer to STC-13, "Protection Function".
Extensive steering at low speed will cause the EPS control unit and EPS motor to heat up, once temperature reaches critical point EPS control unit will reduce current to reduce heat up. System will recover as temperature lowers (reduced or no assistance).

EPS Warning lamp indication
Turn ON when there is a malfunction in EPS system. If 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.

CAUTION:
EPS warning lamp also turns ON due to data reception error, CAN communication error etc.
EPS SYSTEM : Fail-Safe
If any malfunction occurs in the system and control unit detects the malfunction, EPS warning lamp on combination meter turns ON to indicate system malfunction.
When EPS warning lamp is ON, the system enters into a manual steering state. (Control turning force steering wheel becomes heavy.)
Under abnormal vehicle speed signal conditions, vehicle speed is judged as constant.
EPS SYSTEM : Protection Function
EPS control unit decreases the output signal to EPS motor while extremely using the power steering function (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection control).
While activating overload protection control, the assist torque gradually decreases, and the steering wheel turning force becomes heavy. The normal assist torque is recovered if the steering wheel is not turned for a while.
Warning/indicator/chime list
WARNING/INDICATOR/CHIME LIST : Warning Lamp/Indicator Lamp

Component parts
Diagnosis system (EPS control unit)NISSAN vehicle immobilizer system
The NISSAN Vehicle Immobilizer system will not
allow the engine to start without the use of the
registered key.
If the engine fails to start using a registered key
(for example, when interference is caused by
another registered key, an automated toll road
device or automatic payment device o ...
Headlamp (hi) circuit
Description
The IPDM E/R (intelligent power distribution module engine room) controls the
headlamp high relay based on
inputs from the BCM over the CAN communication lines. When the headlamp high
relay is energized, power
flows through fuses 41 and 42, located in the IPDM E/R. Power then flo ...
Main power supply and ground circuit
Diagnosis Procedure
1.CHECK TCM POWER CIRCUIT (PART 1)
Turn ignition switch OFF.
Disconnect TCM connector.
Check voltage between TCM harness connector terminals and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 4.
2.CHECK TCM POWER CIRCUIT (PAR ...