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Infiniti I30. Emission Control System (2003 year). Manual - part 29

CHECK MAF SENSOR POWER SUPPLY CIRCUIT

1. Disconnect mass air flow (MAF) sensor harness connector.

SEC055D

2. Turn ignition switch “ON”.
3. Check voltage between MAF sensor terminals 2, 4 and ground with CONSULT-II or tester.

SEF297X

OK or NG

䊳

GO TO 5.

䊳

GO TO 4.

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connectors E15, F18

쐌

Harness for open or short between ECM relay and mass air flow sensor

쐌

Harness for open or short between mass air flow sensor and ECM

䊳

Repair harness or connectors.

CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 80.

Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to power.

OK or NG

䊳

GO TO 6.

䊳

Repair open circuit or short to power in harness or connectors.

IDX

DTC P1102 MAF SENSOR

Diagnostic Procedure (Cont’d)

EC-449

CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between MAF sensor terminal 1 and ECM terminal 62.

Refer to Wiring Diagram.

Continuity should exist.

2. Also check harness for short to ground and short to power.

OK or NG

䊳

GO TO 7.

䊳

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK MASS AIR FLOW SENSOR

1. Reconnect harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 62 (Mass air flow sensor signal) and ground.

SEF391R

MTBL1160

4. If the voltage is out of specification, disconnect MAF sensor harness connector and connect it again.

Then repeat above check.

OK or NG

䊳

GO TO 8.

䊳

Replace mass air flow sensor.

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

䊳

INSPECTION END

DTC P1102 MAF SENSOR

Diagnostic Procedure (Cont’d)

EC-450

Component Description

NHEC1298

Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throttle
valve and feeds the voltage signals to the ECM. The ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening
angle properly in response to driving condition.

On Board Diagnosis Logic

NHEC1299

This self-diagnosis has the one trip detection logic.

DTC No.

Trouble diagnosis

name

DTC detecting condition

Possible cause

P1121
1121

Electric throttle control
actuator

Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.

쐌

Electric throttle control actuator

Throttle valve opening angle in fail-safe mode
is not in specified range.

ECM detect the throttle valve is stuck open.

FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.

Detected items

Engine operating condition in fail-safe mode

Malfunction A

The ECM controls the electric throttle control actuator by regulating the throttle opening around the idle
position. The engine speed will not rise more than 2,000 rpm.

Malfunction B

ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.

Malfunction C

While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in “N” or “P” position, and engine speed will not exceed 1,000 rpm or more.

DTC Confirmation Procedure

NHEC1300

NOTE:

쐌

Perform “PROCEDURE FOR MALFUNCTION A AND B”
first. If the DTC cannot be confirmed, perform “PROCE-
DURE FOR MALFUNCTION C”.
If there is no malfunction on “PROCEDURE FOR MAL-
FUNCTION A AND B”, perform “PROCEDURE FOR MAL-
FUNCTION C”.

쐌

“DTC

Confirmation

Procedure”

has

been

previously

conducted, always turn ignition switch “OFF” and wait at least
10 seconds before conducting the next test.

SEF058Y

PROCEDURE FOR MALFUNCTION A AND B

With CONSULT-II

Turn ignition switch “ON” and wait at least 1 second.

Select “DATA MONITOR” mode with CONSULT-II.

Shift selector lever to “D” position and wait at least 3 seconds.

Turn ignition switch “OFF”, wait at least 10 seconds and then
turn “ON”.

Turn ignition switch “ON” and wait at least 1 second.

Shift selector lever to “D” position and wait at least 3 seconds.

Turn ignition switch “OFF”, wait at least 10 seconds, and then
turn “ON”.

IDX

DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR

Component Description

EC-451

If DTC is detected, go to “Diagnostic Procedure”, EC-452.

With GST

Follow the procedure “WITH CONSULT-II” above.

SEF058Y

PROCEDURE FOR MALFUNCTION C

With CONSULT-II

Turn ignition switch “ON” and wait at least 1 second.

Select “DATA MONITOR” mode with CONSULT-II.

Shift selector lever to “D” position and wait at least 3 seconds.

Shift selector lever to “N” or “P” position.

Start engine and let it idle for 3 seconds.

If DTC is detected, go to “Diagnostic Procedure”, EC-452.

With GST

Follow the procedure “WITH CONSULT-II” above.

Diagnostic Procedure

NHEC1413

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1. Remove the intake air duct.
2. Check if a foreign matter is caught between the throttle valve and the housing.

SEC083D

OK or NG

䊳

GO TO 2.

䊳

Remove the foreign matter and clean the electric throttle control actuator inside.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1. Replace the electric throttle control actuator.
2. Perform “Throttle Valve Closed Position Learning”, EC-71.
3. Perform “Idle Air Volume Learning”, EC-71.

䊳

INSPECTION END

DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR

DTC Confirmation Procedure (Cont’d)

EC-452

Description

NHEC1301

NOTE:
If DTC P1122 is displayed with DTC P1121 or P1126, first perform the trouble diagnosis for DTC P1121
or P1126. Refer to EC-451, 461.
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides the
feedback to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.

On Board Diagnosis Logic

NHEC1448

This self-diagnosis has the one trip detection logic.

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P1122
1122

Electric throttle con-
trol performance
problem

Electric throttle control function does not operate
properly.

쐌

Harness or connectors
(Throttle control motor circuit is open
or shorted.)

쐌

Electric throttle control actuator

FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.

Engine operating condition in fail-safe mode

ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the
return spring.

DTC Confirmation Procedure

NHEC1449

NOTE:
If “DTC Confirmation Procedure” has been previously conducted,
always turn ignition switch “OFF” and wait at least 10 seconds
before conducting the next test.
TEST CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 11V when engine is running.

SEF058Y

With CONSULT-II

Turn ignition switch “ON” and wait at least 2 seconds.

Select “DATA MONITOR” mode with CONSULT-II.

Start engine and let it idle for 5 seconds.

If DTC is detected, go to “Diagnostic Procedure”, EC-456.

IDX

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Description

EC-453

With GST

Follow the procedure “WITH CONSULT-II” above.

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

DTC Confirmation Procedure (Cont’d)

EC-454

Wiring Diagram

NHEC1304

MEC359E

IDX

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Wiring Diagram

EC-455

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM’s transistor. Use a ground other than ECM terminals, such as the ground.

TERMI-

NAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA (DC Voltage)

Throttle control motor
relay

[Ignition switch “OFF”]

BATTERY VOLTAGE
(11 - 14V)

[Ignition switch “ON”]

0 - 1.0V

101

Throttle control motor
(Open)

[Ignition switch “ON”]

쐌

Engine stopped

쐌

Shift lever position is “D”

쐌

Accelerator pedal is fully depressed

0 - 14V

★

SEC037D

102

Throttle control motor
relay power supply

[Ignition switch “ON”]

BATTERY VOLTAGE
(11 - 14V)

103

Throttle control motor
(Close)

[Ignition switch “ON”]

쐌

Engine stopped

쐌

Shift lever position is “D”

쐌

Accelerator pedal is released

0 - 14V

★

SEC038D

107

Throttle control motor
ground

[Engine is running]

쐌

Idle speed

Approximately 0V

★

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

Diagnostic Procedure

NHEC1305

RETIGHTEN GROUND SCREWS

1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.

SEC047D

䊳

GO TO 2.

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Wiring Diagram (Cont’d)

EC-456

CHECK THROTTLE CONTROL MOTOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 107 and engine ground.

Refer to Wiring Diagram.

Continuity should exist.

3. Also check harness for short to power.

OK or NG

䊳

GO TO 3.

䊳

Repair open circuit or short to power in harness or connectors.

CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I

1. Reconnect harness connector disconnected.
2. Check voltage between ECM terminal 102 and ground under the following conditions with CONSULT-II or tester.

MTBL1168

OK or NG

䊳

GO TO 12.

䊳

GO TO 4.

CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT

1. Turn ignition switch “OFF”.
2. Disconnect throttle control motor relay.

SEC044D

3. Check voltage between throttle control motor relay terminals 2, 5 and ground with CONSULT-II or tester.

SEC091D

Voltage: Battery voltage

OK or NG

䊳

GO TO 6.

䊳

GO TO 5.

IDX

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Diagnostic Procedure (Cont’d)

EC-457

DETECT MALFUNCTIONING PART

Check the following.

쐌

15A fuse

쐌

Harness for open and short between throttle control motor relay and fuse

䊳

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 102 and throttle control motor relay terminal 3.

Refer to Wiring Diagram.

Continuity should exist.

3. Also check harness for short to ground and short to power.

OK or NG

䊳

GO TO 8.

䊳

GO TO 7.

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connector E15, F18

쐌

Harness for open and short between throttle control motor relay and ECM

䊳

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK THROTTLE CONTROL MOTOR RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ECM terminal 26 and throttle control motor relay terminal 1.

Refer to Wiring Diagram.

Continuity should exist.

2. Also check harness for short to ground and short to power.

OK or NG

䊳

GO TO 10.

䊳

GO TO 9.

DETECT MALFUNCTIONING PART

Check the following.

쐌

Harness connector E81, M15

쐌

Harness connectors M223, F53

쐌

Harness for open and short between throttle control motor relay and ECM

䊳

Repair open circuit or short to ground or short to power in harness or connectors.

CHECK THROTTLE CONTROL MOTOR RELAY

Refer to “Component Inspection”, EC-460.

OK or NG

䊳

GO TO 11.

䊳

Replace throttle control motor relay.

CHECK INTERMITTENT INCIDENT

Perform “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

䊳

INSPECTION END

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Diagnostic Procedure (Cont’d)

EC-458

CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT

1. Turn ignition switch “OFF”.
2. Disconnect electric throttle control actuator harness connector.

SEC054D

3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.

Refer to Wiring Diagram.

MTBL1169

5. Also check harness for short to ground and short to power.

OK or NG

䊳

GO TO 13.

䊳

Repair or replace.

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1. Remove the intake air duct.
2. Check if foreign matter is caught between the throttle valve and the housing.

SEC083D

OK or NG

䊳

GO TO 14.

䊳

Remove the foreign matter and clean the electric throttle control actuator inside.

IDX

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Diagnostic Procedure (Cont’d)

EC-459

CHECK THROTTLE CONTROL MOTOR

Refer to “Component Inspection”, EC-460.

OK or NG

䊳

GO TO 15.

䊳

GO TO 16.

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-151.

OK or NG

䊳

GO TO 16.

䊳

Repair or replace harness or connectors.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1. Replace the electric throttle control actuator.
2. Perform “Throttle Valve Closed Position Learning”, EC-71.
3. Perform “Idle Air Volume Learning”, EC-71.

䊳

INSPECTION END

PBIB0095E

Component Inspection

NHEC1306

THROTTLE CONTROL MOTOR

NHEC1306S01

Disconnect electric throttle control actuator harness connector.

Check resistance between terminals 3 and 6.

Resistance: Approximately 1 - 15

Ω

[at 25°C (77°F)]

If NG, replace electric throttle control actuator and go to next
step.

Perform “Throttle Valve Closed Position Learning”, EC-71.

Perform “Idle Air Volume Learning”, EC-71.

PBIB0098E

THROTTLE CONTROL MOTOR RELAY

NHEC1306S02

Apply 12V direct current between relay terminals 1 and 2.

Check continuity between relay terminals 3 and 5.

Conditions

Continuity

12V direct current supply between ter-
minals 1 and 2

Yes

No current supply

If NG, replace throttle control motor relay.

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION

Diagnostic Procedure (Cont’d)

EC-460

Component Description

NHEC1307

Power supply for the Throttle Control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition switch
is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not pro-
vided to the ECM.

CONSULT-II Reference Value in Data Monitor
Mode

NHEC1319

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

THRTL RELAY

쐌

Ignition switch: ON

On Board Diagnosis Logic

NHEC1450

These self-diagnoses have the one trip detection logic.

DTC No.

Trouble diagnosis

name

DTC Detecting Condition

Possible Cause

P1124
1124

Throttle control motor
relay circuit short

ECM detect the throttle control motor relay is stuck
ON.

쐌

Harness or connectors
(Throttle control motor relay circuit is
shorted)

쐌

Throttle control motor relay

P1126
1126

Throttle control motor
relay circuit open

ECM detects a voltage of power source for throttle
control motor is excessively low.

쐌

Harness or connectors
(Throttle control motor relay circuit is
open)

쐌

Throttle control motor relay

FAIL-SAFE MODE

NHEC1450S01

When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.

Engine operating condition in fail-safe mode

ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the
return spring.

DTC Confirmation Procedure

NHEC1451

NOTE:
If “DTC Confirmation Procedure” has been previously conducted,
always turn ignition switch “OFF” and wait at least 10 seconds
before conducting the next test.
PROCEDURE FOR DTC P1124
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 8V.

SEF058Y

With CONSULT-II

Turn ignition switch “ON” and wait at least 1 second.

Select “DATA MONITOR” mode with CONSULT-II.

If DTC is detected, go to “Diagnostic Procedure”, EC-464.

With GST

Follow the procedure “With CONSULT-II” above.

IDX

DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY

Component Description

EC-461

SEF058Y

PROCEDURE FOR DTC P1126

With CONSULT-II

Turn ignition switch “ON” and wait at least 2 seconds.

Select “DATA MONITOR” mode with CONSULT-II.

Start engine and let it idle for 5 seconds.

If DTC is detected, go to “Diagnostic Procedure”, EC-464.

With GST

Follow the procedure “With CONSULT-II” above.

DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY

DTC Confirmation Procedure (Cont’d)

EC-462

Wiring Diagram

NHEC1310

MEC360E

IDX

DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY

Wiring Diagram

EC-463

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM’s transistor. Use a ground other than ECM terminals, such as the ground.

TERMI-

NAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA (DC Voltage)

Throttle control motor
relay

[Ignition switch “OFF”]

BATTERY VOLTAGE
(11 - 14V)

[Ignition switch “ON”]

0 - 1.0V

102

Throttle control motor
relay power supply

[Ignition switch “ON”]

BATTERY VOLTAGE
(11 - 14V)

Diagnostic Procedure

NHEC1311

CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT

1. Turn ignition switch “OFF”.
2. Disconnect throttle control motor relay.

SEC044D

3. Check voltage between throttle control motor relay terminals 2, 5 and ground with CONSULT-II or tester.

SEC091D

Voltage: Battery voltage

OK or NG

䊳

GO TO 3.

䊳

GO TO 2.

DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY

Wiring Diagram (Cont’d)

EC-464

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