Nissan Frontier D22. Manual - part 255

POWER SUPPLY CIRCUIT FOR ECM

EC-123

[KA24DE]

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2. 

CHECK POWER SUPPLY-I

1.

Turn ignition switch OFF and then ON.

2.

Check voltage between ECM terminal 24 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 12.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M65, E43

●

Harness connectors M59, F27

●

Fuse block (J/B) connector E49

●

10A fuse

●

Harness for open or short between ECM and fuse

>> Repair harness or connectors.

4. 

CHECK POWER SUPPLY-II

1.

Stop engine.

2.

Check voltage between ECM terminal 80 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M81, F36

●

Fuse block (J/B) connector M27

●

10A fuse

●

Harness for open or short between ECM and fuse

>> Repair harness or connectors.

Voltage

: Battery voltage

SEF600P

Voltage

: Battery voltage

MEC698B

EC-124

[KA24DE]

POWER SUPPLY CIRCUIT FOR ECM

6. 

CHECK POWER SUPPLY-III

1.

Turn ignition switch ON and then OFF.

2.

Check voltage between ECM terminals 67, 72, 117 and ground
with CONSULT-II or tester.

OK or NG

OK

>> GO TO 12.

NG (Battery voltage does not exist.)>>GO TO 7.
NG (Battery voltage exists for more than a few seconds.)>>GO  TO

11.

7. 

CHECK HARNESS CONTINUITY BETWEEN ECM RELAY AND ECM

1.

Disconnect ECM harness connector.

2.

Disconnect ECM relay.

3.

Check harness continuity between ECM terminals 67, 72, 117
and ECM relay terminal 3.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 8

NG

>> Repair open circuit or short to ground or short to power

in harness or connectors.

8. 

CHECK VOLTAGE BETWEEN ECM RELAY AND GROUND

Check voltage between ECM relay terminals 2, 5 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 9.

9. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness for open or short between ECM relay and harness connector F36

>> Repair harness or connectors.

Voltage

: After turning ignition switch OFF, battery 
voltage will exist for a few seconds, then 
drop to approximately 0V.

PBIB2168E

Continuity should exist.

LEC106A

Voltage

: Battery voltage

SEF120V

POWER SUPPLY CIRCUIT FOR ECM

EC-125

[KA24DE]

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EC

10. 

CHECK OUTPUT SIGNAL CIRCUIT

1.

Check harness continuity between ECM terminal 4 and ECM relay terminal 1.
Refer to Wiring Diagram.

2.

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

OK or NG

OK

>> GO TO 11.

NG

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

11. 

CHECK ECM RELAY

1.

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

2.

Check continuity between ECM relay terminals 3 and 5.

OK or NG

OK

>> GO TO 12.

NG

>> Replace ECM relay.

12. 

CHECK GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminals 10, 19, 25, 32, 116, 124 and engine ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 13.

NG

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

13. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-120, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END.

Continuity should exist.

12V (1 - 2) applied

: Continuity exists.

No voltage applied

: No continuity

SEF511P

Continuity should exist.

EC-126

[KA24DE]

DTC P0031, P0032 HO2S1 HEATER

DTC P0031, P0032 HO2S1 HEATER

PFP:22690

Description

UBS00D1X

SYSTEM DESCRIPTION

The ECM performs ON/OFF duty control of the heated oxygen sensor 1 heater corresponding to the engine
speed and engine coolant temperature. The duty percent varies with engine coolant temperature when engine
is started.

OPERATION

CONSULT-II Reference Value in Data Monitor Mode

UBS00D1Y

Specification data are reference values.

On Board Diagnosis Logic

UBS00D1Z

Sensor

Input Signal to ECM

ECM function

Actuator

Camshaft position sensor

Engine speed

Heated oxygen sensor 1 
heater control

Heated oxygen sensor 1 heater

Engine coolant temperature sensor

Engine coolant temperature

Engine speed

Heated oxygen sensor 1 heater

Above 3,600 rpm

OFF

Below 3,600 rpm after warming up

ON

MONITOR ITEM

CONDITION

SPECIFICATION

HO2S1 HTR (B1)

●

Engine: After warming up

●

Engine speed: Below 3,600 rpm 

ON

●

Engine speed: Above 3,600 rpm

OFF

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P0031

Heated oxygen 
sensor 1 heater 
control circuit low

The current amperage in the heated oxygen 
sensor 1 heater circuit is out of the normal 
range.
(An excessively low voltage signal is sent to 
ECM through the heated oxygen sensor 1 
heater.)

●

Harness or connectors
(The heated oxygen sensor 1 heater circuit is 
open or shorted.)

●

Heater oxygen sensor 1 heater

P0032

Heated oxygen 
sensor 1 heater 
control circuit high

The current amperage in the heated oxygen 
sensor 1 heater circuit is out of the normal 
range.
(An excessively high voltage signal is sent to 
ECM through the heated oxygen sensor 1 
heater.)

●

Harness or connectors
(The heated oxygen sensor 1 heater circuit is 
shorted.)

●

Heater oxygen sensor 1 heater