Nissan Sentra. Manual - part 348

EC-88

< ECU DIAGNOSIS INFORMATION >

[MRA8DE]

ECM

84

(W)

—

Sensor power supply
(Intake manifold runner 
control valve position sen-
sor)

—

[Ignition switch: ON]

More than 4.98 V

86

(R)

128

(B/Y)

Ignition signal No. 1

Output

[Engine is running]
• Warm-up condition
• Idle speed

NOTE:
The pulse cycle changes depending 
on rpm at idle

0 - 0.1 V

87

(LG)

Ignition signal No. 2

90

(P)

Ignition signal No. 3

[Engine is running]
• Warm-up condition
• Engine speed: 2,000 rpm

0 - 0.2 V

91

(SB)

Ignition signal No. 4

89

(GR)

128

(B/Y)

ECM relay
(Self shut-off)

Output

[Engine is running]
[Ignition switch: OFF]
• A few seconds after turning ignition 

switch OFF

0 - 1.0 V

[Ignition switch: OFF]
• More than a few seconds after turn-

ing ignition switch OFF

Battery voltage

(11 - 14 V)

92

(LG)

—

Sensor ground
(Intake manifold runner 
control valve position sen-
sor)

—

—

—

93

(LG)

128

(B/Y)

Intake valve timing control 
solenoid valve

Output

[Engine is running]
• Warm-up condition
• Idle speed

0 V

[Engine is running]
• Warm-up condition
• When revving engine up to 2,000 

rpm quickly

11 – 14 V 

94

(G)

128

(B/Y)

Exhaust valve timing con-
trol solenoid valve

Output

[Engine is running]
• Warm-up condition
• Idle speed

0 V

[Engine is running]
• Warm-up condition
• Engine speed: 2,000 rpm

Battery voltage

(11 - 14 V)

97

(BR)

128

(GR)

EVAP canister vent con-
trol valve

Output

[Ignition switch: ON]

Battery voltage

(11 - 14 V) 

99

(P)

—

CAN communication line
(CAN-L)

Input/

Output

—

—

Terminal No.

(Wire color)

Description

Condition

Value

(Approx.)

+

−

Signal name

Input/

Output

JPBIA4733ZZ

JPBIA4734ZZ

JMBIA1638GB

ECM

EC-89

< ECU DIAGNOSIS INFORMATION >

[MRA8DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

100

(L)

—

CAN communication line
(CAN-H)

Input/

Output

—

—

101

(G)

128

(B/Y)

Starter relay cut off signal

Input/

Output

[Ignition switch: ON]

0 V

[Engine is running]
• Warm-up condition
• Idle speed

Battery voltage

(11 - 14 V)

103

(P)

124

(Y)

Refrigerant pressure sen-
sor

Input

[Engine is running]
• Warm-up condition
• Both A/C switch and blower fan mo-

tor switch: ON (Compressor oper-
ates)

1.0 - 4.0 V

104

(L)

—

Sensor power supply
(Refrigerant pressure 
sensor)

—

[Ignition switch: ON]

5.0 V

105

(V)

128

(B/Y)

Starter motor relay control 
signal

Output

[Engine is running]
• Warm-up condition
• Idle speed
• Selector lever: D (CVT)
• Shift lever: 1st (M/T)
• Engine speed: Less than 1,500 rpm
NOTE:
To decrease engine speed, perform 
the DTC confirmation procedure B in 
P1650. Refer to 

EC-399, "DTC Logic"

.

0 V

(While operating the starter mo-

tor)

[Engine is running]
• Warm-up condition
• Idle speed

Battery voltage

(11 - 14 V)

109

(O)

128

(B/Y)

Ignition switch

Input

[Ignition switch: OFF]

0 V

[Ignition switch: ON]

Battery voltage

(11 - 14 V)

110

(P)

111

(B)

ASCD steering switch

Input

[Ignition switch: ON]
• ASCD steering switch: OFF

4 V

[Ignition switch: ON]
• MAIN switch: Pressed

0 V

[Ignition switch: ON]
• CANCEL switch: Pressed

1 V

[Ignition switch: ON]
• ACCEL/RES switch: Pressed

3 V

[Ignition switch: ON]
• COAST/SET switch: Pressed

2 V

111

(B)

—

Sensor ground
(ASCD steering switch)

—

—

—

113

(G)

—

Sensor power supply
(EVAP control system 
pressure sensor)

—

[Ignition switch: ON]

5.0 V

114

(P)

124

(SB)

EVAP control system 
pressure sensor

Input

[Ignition switch: ON]

0.5 - 4.6 V

115

(SB)

128

(B/Y)

Stop lamp switch

Input

[Ignition switch: OFF]
• Brake pedal: Fully released

0 V

[Ignition switch: OFF]
• Brake pedal: Slightly depressed

Battery voltage

(11 - 14 V)

Terminal No.

(Wire color)

Description

Condition

Value

(Approx.)

+

−

Signal name

Input/

Output

EC-90

< ECU DIAGNOSIS INFORMATION >

[MRA8DE]

ECM

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to 

PG-4, "How to Han-

dle Battery"

.

Fail Safe

INFOID:0000000009758391

NON DTC RELATED ITEM

116

(G)

128

(B/Y)

Brake pedal position 
switch

Input

[Ignition switch: OFF]
• Brake pedal: Fully released

Battery voltage

(11 - 14 V)

[Ignition switch: OFF]
• Brake pedal: Slightly depressed

0 V

117

(BR)

128

(B/Y)

• PNP signal (CVT)
• Neutral switch (M/T)

Input

[Ignition switch: ON]
• Selector lever: P or N (CVT)
• Shifter  lever: Neutral (M/T)

Battery voltage

(11 - 14 V)

[Ignition switch: ON]
• Except above

0 V

118

(O)

—

Sensor power supply
(Accelerator pedal posi-
tion sensor 2)

—

[Ignition switch: ON]

5.0 V

119
(W)

120

(Y)

Accelerator pedal posi-
tion sensor 2

Input

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released

0.3 – 0.6 V

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed

1.95 – 2.4 V

120

(Y)

—

Sensor ground
(Accelerator pedal posi-
tion sensor 2)

—

—

—

121

(G)

128

(B/Y)

Power supply for ECM

Input

[Ignition switch: ON]

Battery voltage

(11 - 14 V)

122

(V)

—

Sensor power supply
(Accelerator pedal posi-
tion sensor 1)

—

[Ignition switch: ON]

5.0 V

123

(B/Y)

—

ECM ground

—

—

—

124

(V)

—

Sensor ground
(EVAP control system 
pressure sensor, refriger-
ant pressure sensor)

—

—

—

126

(R)

127

(GR)

Accelerator pedal posi-
tion sensor 1

Input

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released

0.6 – 0.9 V

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed

3.9 – 4.7 V

127

(GR)

—

Sensor ground
(Accelerator pedal posi-
tion sensor 1)

—

—

—

128

(B/Y)

—

ECM ground

—

—

—

Terminal No.

(Wire color)

Description

Condition

Value

(Approx.)

+

−

Signal name

Input/

Output

ECM

EC-91

< ECU DIAGNOSIS INFORMATION >

[MRA8DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

DTC RELATED ITEM

Description

When a DTC is detected, ECM executes a mode (in the Fail-safe mode) applicable to the DTC. The fail-safe

mode has the preset traveling control mode (accelerator angle variation and engine output limit) and device fix

mode.

Fail Safe Pattern

Fail Safe List

×:Applicable —: Not applicable

Detected 

items

Engine operating condition 

in fail-safe mode

Remarks

Reference page

Malfunction 
indicator 
circuit

Engine speed will not rise 
more than 2,500 rpm due 
to the fuel cut

When there is an open circuit on MIL circuit, the ECM cannot warn the 
driver by lighting up MIL when there is malfunction on engine control 
system.
Therefore, when electrical controlled throttle and part of ECM related 
diagnoses are continuously detected as NG for 5 trips, ECM warns the 
driver that engine control system malfunctions and MIL circuit is open 
by means of operating fail safe function.
The fail safe function also operates when above diagnoses except MIL 
circuit are detected and demands the driver to repair the malfunction.

EC-467, "Compo-
nent Function 
Check"

Fail safe mode

Vehicle behavior

Traveling con-
trol mode

Accelerator an-
gle variation 
control

ECM controls the accelerator pedal depression speed to make it slower than actual speed. This 
causes a drop in accelerating performance and encourages the driver to repair malfunction.
NOTE:
ECM does not control the accelerator pedal releasing speed.

Engine output 
control

ECM reduces the engine output, according to the rise in engine speed. This reduces the vehicle 
speed to encourage the driver to repair malfunction.

Device fix mode

• This mode fixes the IVT control solenoid valve and the EVT control solenoid valve in the refer-

ence position.

• The intake manifold runner control valve motor is turned OFF (intake manifold runner control 

valve opens).

Pattern

Fail safe mode

A

Traveling control mode

Accelerator angle variation control

B

Engine output control

C

Device fix mode

DTC 

No.

Detected items

Vehicle behavior

Pattern

Others

A

B

C

P0075

Intake valve timing control

—

—

×

ECM activates the IVT intermediate lock control solenoid 
valve to bring the cam sprocket into an intermediate lock con-
dition.

P0078

Exhaust valve timing control

—

—

×

—

P0101
P0102
P0103

Mass air flow sensor circuit

×

×

×

—

P0122
P0123
P0222
P0223
P2135

Throttle position sensor

—

—

—

The ECM controls the electric throttle control actuator in reg-
ulating the throttle opening in order for the idle position to be 
within +10 degrees.
The ECM regulates the opening speed of the throttle valve to 
be slower than the normal condition.
So, the acceleration will be poor.