DIDYN−01

−DIAGNOSTICS ENGINEDI−91

1HD−FTV ENGINE SUP (RM1179E)

CIRCUIT INSPECTION

DTC P1222/15 Throttle Motor Circuit

CIRCUIT DESCRIPTIONThe throttle control motor is operated by the engine ECU and it opens and closes the throttle valve.The fully open condition of the throttle valve is detected by the diesel throttle position switch, which ismounted on the throttle body.If this DTC is stored, the engine ECU shuts down the power for the throttle control motor.

DTC No. DTC Detection Condition Trouble Area

O h t i th ttl t l t i it

SOpen or short in throttle control motor circuitSOpen or short in diesel throttle position switch circuit

P1222/15

Open or short in throttle control motor circuit SThrottle control motorSThrottle valveSThrottle drive gear

Open or short in diesel throttle position switch circuit

SThrottle drive gearSDiesel throttle bodySDiesel throttle position switchSEngine ECU

A23871

T3Diesel Throttle Control Motor

6

1

3

4

G−R

V

Engine ECU

G

LU+A

LU+B

LU−A

LU−B

15

13

14

12

E16

THOP

15

1

2

GR

D32Diesel ThrottlePosition Switch W−B

E1617

E01

G−W

E16

E16

E16

E17

LU+A

LU+B

LU−A

LU−B

+B1

+B25

2BR

ED ED

MAIN

4

5C3 2

2A

Cowl Side J/B LH

Engine Room J/B

44

Battery

EFI OR ECD NO. 1

F37FusibleLink Block

J/B No. 5

W−B

EFI ORECDRelay MREL

1B

1

2B−W

15

B

8

E195D

IV21

SB

EFI ORECD NO. 2

2Q5 45

B−YB−W

1 1

11

Battery

2 B−GW−B

EEEA

1 1C

11 1B

W−BG−Y

43 1A 1B

B−Y

B−Y

B−Y

39

Engine Room R/B

DI−92−DIAGNOSTICS ENGINE

1HD−FTV ENGINE SUP (RM1179E)

WIRING DIAGRAM

A09818

Signal Waveform

10 V/Division

GND

0.5 msec./Division

A23893

+B1

+B2

−DIAGNOSTICS ENGINEDI−93

1HD−FTV ENGINE SUP (RM11 79E)

INSPECTION PROCEDUREHINT:Read freeze frame data using the intelligent tester II. Freeze frame data records the engine conditions whena malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle wasrunning or stopped, if the engine was warmed up or not, and other data from the time the malfunction oc-curred.

1 Check throttle control motor circuit.

PREPARATION:(a) Connect t he oscilloscope bet ween t er m inals LU+ A,

LU+B, LU−A, LU−B and E01 of the engine ECU.(b) Start the engine.CHECK:Check the waveform between terminals LU+A, LU+B, LU−A,LU−B and E01 of the engine ECU when the engine is racing.OK:

The correct waveforms are as shown.

OK Go to step 5.

NG

2 Check voltage of throttle control motor circuit.

PREPARATION:(a) Disconnect the throttle control motor.(b) Turn the ignition switch ON.CHECK:Measure the voltage between terminals 2 and 5 of the throttlecontrol motor connector and body ground.OK:

Voltage: 9 to 14 V

NG Check for open in harness and connector be-tweenEFIORECD relay and throttle controlmo-tor (See page IN−1 9) .

OK

A16946

123456

Ohmmeter

DI−94−DIAGNOSTICS ENGINE

1HD−FTV ENGINE SUP (RM1179E)

3 Check throttle control motor.

PREPARATION:Disconnect the throttle control motor connector.CHECK:S Measure the resistance between terminals 1, 3 and 2 of

the throttle control motor.S Measure the resistance between terminals 4, 6 and 5 of

the throttle control motor.OK:

Resistance: 18 to 22 � at 20˚C (68˚F)

NG Replace diesel throttle body assembly (See PubNo. RM896E, page ED−1).

OK

4 Check for open and short in harness and connector between throttle control mo-tor and engine ECU (See page IN−1 9) .

NG Repair or replace harness or connector.

OK

Check and replace engine ECU (See pageIN−1 9) .

A23900Ohmmeter

−DIAGNOSTICS ENGINEDI−95

1HD−FTV ENGINE SUP (RM1179E)

5 Check diesel throttle position switch.

PREPARATION:Disconnector the diesel throttle position switch.CHECK:Measure the resistance between terminal of the diesel throttleposition switch.OK:

Throttle Valve Position Diesel throttle position switch signal

Fully closed 10 k� or higher

Fully open Below 1 �

NG Replace diesel throttle body assembly (See PubNo. RM896E, page ED−1).

OK

6 Check for open and short in harness and connector between diesel throttle posi-tion switch and engine ECU (See page IN−1 9) .

NG Repair or replace harness or connector.

OK

7 Check for open and short in harness and connector between diesel throttle posi-tion switch and body ground (See page IN−1 9) .

NG Repair or replace harness or connector.

OK

Check and replace engine ECU (See pageIN−1 9) .