Subaru Legacy (2005 year). Manual — part 324

EN(H4DOTC)(diag)-65

ENGINE (DIAGNOSTICS)

List of Diagnostic Trouble Code (DTC)

P1577

IMM Control Module EEPROM

<Ref. to IM(diag)-25, DTC P1577 IMM CONTROL MODULE EEPROM,
Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P1578

Meter Failure

<Ref. to IM(diag)-25, DTC P1578 METER FAILURE, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

P2088

Intake Camshaft Position Actuator
Control Circuit Low (Bank 1)

<Ref. to EN(H4DOTC)(diag)-168, DTC P2088 INTAKE CAMSHAFT POSI-
TION ACTUATOR CONTROL CIRCUIT LOW (BANK 1), Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2089

Intake Camshaft Position Actuator
Control Circuit High (Bank 1)

<Ref. to EN(H4DOTC)(diag)-170, DTC P2089 INTAKE CAMSHAFT POSI-
TION ACTUATOR CONTROL CIRCUIT HIGH (BANK 1), Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2090

Exhaust Camshaft Position Actua-
tor Control Circuit Low (Bank 1)

<Ref. to EN(H4DOTC)(diag)-172, DTC P2090 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT LOW (BANK 1), Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

P2091

Exhaust Camshaft Position Actua-
tor Control Circuit High (Bank 1)

<Ref. to EN(H4DOTC)(diag)-174, DTC P2091 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT HIGH (BANK 1), Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

P2092

Intake Camshaft Position Actuator
Control Circuit Low (Bank 2)

<Ref. to EN(H4DOTC)(diag)-176, DTC P2092 INTAKE CAMSHAFT POSI-
TION ACTUATOR CONTROL CIRCUIT LOW (BANK 2), Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2093

Intake Camshaft Position Actuator
Control Circuit High (Bank 2)

<Ref. to EN(H4DOTC)(diag)-178, DTC P2093 INTAKE CAMSHAFT POSI-
TION ACTUATOR CONTROL CIRCUIT HIGH (BANK 2), Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2094

Exhaust Camshaft Position Actua-
tor Control Circuit Low (Bank 2)

<Ref. to EN(H4DOTC)(diag)-180, DTC P2094 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT LOW (BANK 2), Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

P2095

Exhaust Camshaft Position Actua-
tor Control Circuit High (Bank 2)

<Ref. to EN(H4DOTC)(diag)-182, DTC P2095 EXHAUST CAMSHAFT
POSITION ACTUATOR CONTROL CIRCUIT HIGH (BANK 2), Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

P2101

Throttle Actuator Control Motor Cir-
cuit Range/Performance

<Ref. to EN(H4DOTC)(diag)-183, DTC P2101 THROTTLE ACTUATOR
CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2102

Throttle Actuator Control Motor Cir-
cuit Low

<Ref. to EN(H4DOTC)(diag)-189, DTC P2102 THROTTLE ACTUATOR
CONTROL MOTOR CIRCUIT LOW, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>

P2103

Throttle Actuator Control Motor Cir-
cuit High

<Ref. to EN(H4DOTC)(diag)-192, DTC P2103 THROTTLE ACTUATOR
CONTROL MOTOR CIRCUIT HIGH, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>

P2109

Throttle/Pedal Position Sensor “A”
Minimum Stop Performance

<Ref. to EN(H4DOTC)(diag)-193, DTC P2109 THROTTLE/PEDAL POSI-
TION SENSOR “A” MINIMUM STOP PERFORMANCE, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P2122

Throttle/Pedal Position Sensor/
Switch “D” Circuit Low Input

<Ref. to EN(H4DOTC)(diag)-194, DTC P2122 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “D” CIRCUIT LOW INPUT, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

P2123

Throttle/Pedal Position Sensor/
Switch “D” Circuit High Input

<Ref. to EN(H4DOTC)(diag)-197, DTC P2123 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “D” CIRCUIT HIGH INPUT, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

P2127

Throttle/Pedal Position Sensor/
Switch “E” Circuit Low Input

<Ref. to EN(H4DOTC)(diag)-199, DTC P2127 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “E” CIRCUIT LOW INPUT, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

P2128

Throttle/Pedal Position Sensor/
Switch “E” Circuit High Input

<Ref. to EN(H4DOTC)(diag)-202, DTC P2128 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “E” CIRCUIT HIGH INPUT, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

P2135

Throttle/Pedal Position Sensor/
Switch “A”/“B” Voltage Correlation

<Ref. to EN(H4DOTC)(diag)-204, DTC P2135 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “A” / “B” VOLTAGE CORRELATION, Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

DTC

Item

Reference

EN(H4DOTC)(diag)-66

ENGINE (DIAGNOSTICS)

List of Diagnostic Trouble Code (DTC)

P2138

Throttle/Pedal Position Sensor/
Switch “D”/“E” Voltage Correlation

<Ref. to EN(H4DOTC)(diag)-208, DTC P2138 THROTTLE/PEDAL POSI-
TION SENSOR/SWITCH “D” / “E” VOLTAGE CORRELATION, Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>

P2228

Barometric Pressure Circuit Low

<Ref. to EN(H4DOTC)(diag)-212, DTC P2228 BAROMETRIC PRESSURE
CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P2229

Barometric Pressure Circuit High

<Ref. to EN(H4DOTC)(diag)-212, DTC P2229 BAROMETRIC PRESSURE
CIRCUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>

DTC

Item

Reference

EN(H4DOTC)(diag)-67

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

18.Diagnostic Procedure with Diagnostic Trouble Code (DTC)

A: DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)

DTC DETECTING CONDITION:
Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-
37, OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)(diag)-30, PROCE-
DURE, Inspection Mode.>.
WIRING DIAGRAM:

EN-03522

SBF-5

B47

1

2

4

6

3

5

E

E

B21

F2

54

A6

A7

A2

A3

A26

A33

A25

ECM

B134

3

1

4

2

B18

3 4

1 2

3

4

1

2

5

6

B21

B47

B18

B134

5

6

7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26 27

28

16 17

18 19 20 21

33 34

29

32

30 31

MAIN RELAY

FRONT OXYGEN
(A/F) SENSOR

BATTERY

A:

1 2 3 4

12 13 14 15

5 6 7 8

16 17 18 19

9 10 11

20 21 22

23 24 25 26 27 28 29 30 31 32 33

35

34

37

36

39

38

41

40

43

42

44

45

47

46

49

48

51

50

53

52

54

A:

EN(H4DOTC)(diag)-68

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK POWER SUPPLY TO FRONT OXY-
GEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between front oxygen
(A/F) sensor connector and engine ground.

Connector & terminal

(B18) No. 3 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Go to step 2.

Repair the power
supply line.

NOTE:
In this case, repair
the following:
• Open circuit of
harness between
main relay and
front oxygen (A/F)
sensor connector
• Poor contact in
front oxygen (A/F)
sensor connector
• Poor contact in
main relay connec-
tor

2

CHECK HARNESS BETWEEN FRONT OXY-
GEN (A/F) SENSOR AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between front oxy-
gen (A/F) sensor connector and ECM connec-
tor.

Connector & terminal

(B18) No. 4 — (B134) No. 2:
(B18) No. 4 — (B134) No. 3:

Is the resistance less than 1
Ω?

Go to step 3.

Repair the open
circuit of harness
between ECM and
front oxygen (A/F)
sensor.

3

CHECK HARNESS BETWEEN FRONT OXY-
GEN (A/F) SENSOR AND ECM.
Measure the resistance between ECM connec-
tor and chassis ground.

Connector & terminal

(B134) No. 2 — Chassis ground:
(B134) No. 3 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 4.

Repair the ground
short circuit of har-
ness between
ECM and front
oxygen (A/F) sen-
sor.

4

CHECK FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between front oxy-
gen (A/F) sensor connector terminals.

Terminals

No. 3 — No. 4:

Is the resistance 2.4

Ω?

Repair the poor
contact in ECM
connector.

Replace the front
oxygen (A/F) sen-
sor. <Ref. to
FU(H4DOTC)-32,
Front Oxygen (A/
F) Sensor.>