Nissan Silvia. Instruction — part 159

Diagnostic Procedure

NMEC0726

1

CHECK INPUT SIGNAL CIRCUIT

1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector and TCM (Transmission control module) harness connector.
3. Check harness continuity between ECM terminal 12 and TCM terminal 7, ECM terminal 44 and terminal TCM 6, ECM

terminal 45 and TCM terminal 5.
Refer to wiring diagram.

Continuity should exist.

OK or NG

OK

©

GO TO 2.

NG

©

Repair harness or connectors.

2

CHECK INPUT SIGNAL CIRCUIT

1. Check harness continuity between ECM terminals 12, 44, 45 and ground.

Refer to wiring diagram.

Continuity should not exist.

2. Also check harness for short to power.

OK or NG

OK

©

GO TO 3.

NG

©

Repair short to ground or short to power in harness.

3

CHECK INTERMITTENT INCIDENT

Refer to “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-82.

©

INSPECTION END

GI

MA

EM

LC

FE

CL

MT

AT

PD

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

DTC 0504 A/T CONTROL

Diagnostic Procedure

EC-151

SEF463R

SEF288D

Component Description

NMEC0727

The heated oxygen sensor 1 (front) is placed into the exhaust
manifold. It detects the amount of oxygen in the exhaust gas com-
pared to the outside air. The heated oxygen sensor 1 (front) has a
closed-end tube made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions. The heated oxygen sensor 1 (front) signal is sent to the
ECM. The ECM adjusts the injection pulse duration to achieve the
ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical
change from 1V to 0V.

CONSULT-II Reference Value in Data Monitor
Mode

NMEC0728

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

O2S1

I

Engine: After warming up

Maintaining engine speed at 2,000
rpm

0 - 0.3V

+,

Approx. 0.6 - 1.0V

M/R F/C MNT

LEAN

+,

RICH

Changes more than 5 times during
10 seconds.

ECM Terminals and Reference Value

NMEC0729

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)

19

W

Heated oxygen sensor
1 (front)

[Engine is running]

I

After warming up to normal operating temperature
and engine speed is 2,000 rpm

0 - Approximately 1.0V

SEC363C

HEATED OXYGEN SENSOR 1 (FRONT)

Component Description

EC-152

Wiring Diagram

NMEC0730

TEC808

GI

MA

EM

LC

FE

CL

MT

AT

PD

AX

SU

BR

ST

RS

BT

HA

SC

EL

IDX

HEATED OXYGEN SENSOR 1 (FRONT)

Wiring Diagram

EC-153

Diagnostic Procedure

NMEC0731

1

INSPECTION START

Do you have CONSULT-II?

Yes or No

Yes

©

GO TO 2.

No

©

GO TO 3.

2

CHECK OVERALL FUNCTION

With CONSULT-II

1. Start engine and warm it up to normal operating temperature.
2. Select M/R F/C MNT in “DATA MONITOR” mode with CONSULT-II.
3. Keep the engine speed at 2,000 rpm under no load, and make sure that the monitors fluctuate between LEAN and

RICH more than five times in 10 seconds.

SEC419C

OK or NG

OK

©

INSPECTION END

NG

©

GO TO 4.

3

CHECK OVERALL FUNCTION

Without CONSULT-II

1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 5 seconds.
3. Set ECM in “Diagnostic test mode-II [Heated oxygen sensor 1 monitor (front)]”. Refer to “How to Switch Diagnostic Test

Modes”, EC-36.

4. Keep the engine speed at 2,000 rpm under no load, and make sure that the MIL comes ON more than five times in 10

seconds.

SAT652J

OK or NG

OK

©

INSPECTION END

NG

©

GO TO 4.

HEATED OXYGEN SENSOR 1 (FRONT)

Diagnostic Procedure

EC-154