Subaru Legacy IV (2008 year). Manual - part 119

EN(H4SO)(diag)-79

Diagnostic Procedure for Subaru Select Monitor Communication

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK POWER SUPPLY CIRCUIT.
Connect the SDI (Subaru Diagnosis Interface) 
or general scan tool to data link connector.

Does SDI or general scan tool 
turn ON?

Go to step 4.

Go to step 2.

2

CHECK POWER SUPPLY CIRCUIT.
Measure the voltage between data link connec-
tor and chassis ground.

Connector & terminal

(B40) No. 16 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 3.

Repair the power 
supply circuit.

NOTE:
In this case, repair
the following item:
• Open or ground
short circuit of har-
ness between bat-
tery and data link
connector
• Blown out of fuse
(M/B No. 13)

3

CHECK HARNESS BETWEEN DATA LINK 
CONNECTOR AND CHASSIS GROUND.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between 
data link connector and chassis ground.

Connector & terminal

(B40) No. 4 — Chassis ground:
(B40) No. 5 — Chassis ground:

Is the resistance less than 5 

:? Repair the poor 

contact of data link 
connector.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and data link
connector
• Open circuit of
harness between
ECM and engine
ground
• Poor contact in
ECM connector
• Poor contact of
coupling connector

4

CHECK HARNESS BETWEEN ECM AND 
DATA LINK CONNECTOR.
1) Disconnect the connectors from ECM, 
TCM, ABS CM, VDC CM, airbag CM and body 
integrated unit.

CAUTION:
When disconnecting the connector from air-
bag control module, always follow the pre-
cautions on AB section. <Ref. to AB-4,
CAUTION, General Description.>
2) Measure the resistance of harness between 
ECM and data link connector.

Connector & terminal

(B136) No. 16 — (B40) No. 7:

Is the resistance less than 1 

:? Go to step 5.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and data link
connector

5

CHECK HARNESS BETWEEN ECM AND 
DATA LINK CONNECTOR.
Measure the resistance between data link con-
nector and chassis ground.

Connector & terminal

(B40) No. 7 — Chassis ground:

Is the resistance 1 M

: or 

more?

Repair the poor 
contact in the ECM 
or data link con-
nector.

Repair the ground 
short circuit of har-
ness between 
ECM and data link 
connector.

EN(H4SO)(diag)-80

List of Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

19.List of Diagnostic Trouble Code (DTC)

A: LIST

DTC

Item

Reference

P0026

Intake Valve Control Solenoid Circuit 
Range/Performance (Bank 1)

<Ref. to EN(H4SO)(diag)-87, DTC P0026 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT RANGE/PERFORMANCE (BANK 1), Diagnostic Procedure 
with Diagnostic Trouble Code (DTC).>

P0028

Intake Valve Control Solenoid Circuit 
Range/Performance (Bank 2)

<Ref. to EN(H4SO)(diag)-89, DTC P0028 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT RANGE/PERFORMANCE (BANK 2), Diagnostic Procedure 
with Diagnostic Trouble Code (DTC).>

P0030

HO2S Heater Control Circuit (Bank 1 
Sensor 1)

<Ref. to EN(H4SO)(diag)-91, DTC P0030 HO2S HEATER CONTROL CIR-
CUIT (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0031

HO2S Heater Control Circuit Low 
(Bank 1 Sensor 1)

<Ref. to EN(H4SO)(diag)-93, DTC P0031 HO2S HEATER CONTROL CIR-
CUIT LOW (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0032

HO2S Heater Control Circuit High 
(Bank 1 Sensor 1)

<Ref. to EN(H4SO)(diag)-95, DTC P0032 HO2S HEATER CONTROL CIR-
CUIT HIGH (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0037

HO2S Heater Control Circuit Low 
(Bank 1 Sensor 2)

<Ref. to EN(H4SO)(diag)-97, DTC P0037 HO2S HEATER CONTROL CIR-
CUIT LOW (BANK 1 SENSOR 2), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0038

HO2S Heater Control Circuit High 
(Bank 1 Sensor 2)

<Ref. to EN(H4SO)(diag)-99, DTC P0038 HO2S HEATER CONTROL CIR-
CUIT HIGH (BANK 1 SENSOR 2), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0068

MAP/MAF - Throttle Position Correla-
tion

<Ref. to EN(H4SO)(diag)-101, DTC P0068 MAP/MAF - THROTTLE POSI-
TION CORRELATION, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0076

Intake Valve Control Solenoid Circuit 
Low (Bank 1)

<Ref. to EN(H4SO)(diag)-103, DTC P0076 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT LOW (BANK 1), Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0077

Intake Valve Control Solenoid Circuit 
High (Bank 1)

<Ref. to EN(H4SO)(diag)-105, DTC P0077 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT HIGH (BANK 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0082

Intake Valve Control Solenoid Circuit 
Low (Bank 2)

<Ref. to EN(H4SO)(diag)-107, DTC P0082 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT LOW (BANK 2), Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0083

Intake Valve Control Solenoid Circuit 
High (Bank 2)

<Ref. to EN(H4SO)(diag)-109, DTC P0083 INTAKE VALVE CONTROL SOLE-
NOID CIRCUIT HIGH (BANK 2), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0101

Mass or Volume Air Flow Circuit 
Range/Performance

<Ref. to EN(H4SO)(diag)-111, DTC P0101 MASS OR VOLUME AIR FLOW 
CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0102

Mass or Volume Air Flow Circuit Low 
Input

<Ref. to EN(H4SO)(diag)-113, DTC P0102 MASS OR VOLUME AIR FLOW 
CIRCUIT LOW INPUT, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0103

Mass or Volume Air Flow Circuit High 
Input

<Ref. to EN(H4SO)(diag)-115, DTC P0103 MASS OR VOLUME AIR FLOW 
CIRCUIT HIGH INPUT, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0107

Manifold Absolute Pressure/Baromet-
ric Pressure Circuit Low Input

<Ref. to EN(H4SO)(diag)-117, DTC P0107 MANIFOLD ABSOLUTE PRES-
SURE/BAROMETRIC PRESSURE CIRCUIT LOW INPUT, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P0108

Manifold Absolute Pressure/Baromet-
ric Pressure Circuit High Input

<Ref. to EN(H4SO)(diag)-119, DTC P0108 MANIFOLD ABSOLUTE PRES-
SURE/BAROMETRIC PRESSURE CIRCUIT HIGH INPUT, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

EN(H4SO)(diag)-81

List of Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

P0111

Intake Air Temperature Sensor 1 Cir-
cuit Range/Performance

<Ref. to EN(H4SO)(diag)-121, DTC P0111 INTAKE AIR TEMPERATURE 
SENSOR 1 CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P0112

Intake Air Temperature Sensor 1 Cir-
cuit Low

<Ref. to EN(H4SO)(diag)-123, DTC P0112 INTAKE AIR TEMPERATURE 
SENSOR 1 CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0113

Intake Air Temperature Sensor 1 Cir-
cuit High

<Ref. to EN(H4SO)(diag)-125, DTC P0113 INTAKE AIR TEMPERATURE 
SENSOR 1 CIRCUIT HIGH, Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0117

Engine Coolant Temperature Circuit 
Low

<Ref. to EN(H4SO)(diag)-127, DTC P0117 ENGINE COOLANT TEMPERA-
TURE CIRCUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0118

Engine Coolant Temperature Circuit 
High

<Ref. to EN(H4SO)(diag)-129, DTC P0118 ENGINE COOLANT TEMPERA-
TURE CIRCUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0122

Throttle/Pedal Position Sensor/Switch 
“A” Circuit Low

<Ref. to EN(H4SO)(diag)-131, DTC P0122 THROTTLE/PEDAL POSITION 
SENSOR/SWITCH “A” CIRCUIT LOW, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0123

Throttle/Pedal Position Sensor/Switch 
“A” Circuit High

<Ref. to EN(H4SO)(diag)-133, DTC P0123 THROTTLE/PEDAL POSITION 
SENSOR/SWITCH “A” CIRCUIT HIGH, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0125

Insufficient Coolant Temperature for 
Closed Loop Fuel Control

<Ref. to EN(H4SO)(diag)-135, DTC P0125 INSUFFICIENT COOLANT TEM-
PERATURE FOR CLOSED LOOP FUEL CONTROL, Diagnostic Procedure 
with Diagnostic Trouble Code (DTC).>

P0126

Insufficient Engine Coolant Tempera-
ture for Stable Operation

<Ref. to EN(H4SO)(diag)-136, DTC P0126 INSUFFICIENT ENGINE COOL-
ANT TEMPERATURE FOR STABLE OPERATION, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P0128

Coolant Thermostat (Engine Coolant 
Temperature Below Thermostat Reg-
ulating Temperature)

<Ref. to EN(H4SO)(diag)-138, DTC P0128 COOLANT THERMOSTAT 
(ENGINE COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING 
TEMPERATURE), Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0131

O2 Sensor Circuit Low Voltage (Bank 
1 Sensor 1)

<Ref. to EN(H4SO)(diag)-139, DTC P0131 O2 SENSOR CIRCUIT LOW 
VOLTAGE (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0132

O2 Sensor Circuit High Voltage (Bank 
1 Sensor 1)

<Ref. to EN(H4SO)(diag)-141, DTC P0132 O2 SENSOR CIRCUIT HIGH 
VOLTAGE (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0133

O2 Sensor Circuit Slow Response 
(Bank 1 Sensor 1)

<Ref. to EN(H4SO)(diag)-143, DTC P0133 O2 SENSOR CIRCUIT SLOW 
RESPONSE (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0134

O2 Sensor Circuit No Activity 
Detected (Bank 1 Sensor 1)

<Ref. to EN(H4SO)(diag)-145, DTC P0134 O2 SENSOR CIRCUIT NO ACTIV-
ITY DETECTED (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0137

O2 Sensor Circuit Low Voltage (Bank 
1 Sensor 2)

<Ref. to EN(H4SO)(diag)-147, DTC P0137 O2 SENSOR CIRCUIT LOW 
VOLTAGE (BANK 1 SENSOR 2), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0138

O2 Sensor Circuit High Voltage (Bank 
1 Sensor 2)

<Ref. to EN(H4SO)(diag)-149, DTC P0138 O2 SENSOR CIRCUIT HIGH 
VOLTAGE (BANK 1 SENSOR 2), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

P0139

O2 Sensor Circuit Slow Response 
(Bank 1 Sensor 2)

<Ref. to EN(H4SO)(diag)-151, DTC P0139 O2 SENSOR CIRCUIT SLOW 
RESPONSE (BANK 1 SENSOR 2), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0140

O2 Sensor Circuit No Activity 
Detected (Bank 1 Sensor 2)

<Ref. to EN(H4SO)(diag)-153, DTC P0140 O2 SENSOR CIRCUIT NO ACTIV-
ITY DETECTED (BANK1 SENSOR2), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0171

System Too Lean (Bank 1)

<Ref. to EN(H4SO)(diag)-155, DTC P0171 SYSTEM TOO LEAN (BANK 1), 
Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

DTC

Item

Reference

EN(H4SO)(diag)-82

List of Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

P0172

System Too Rich (Bank 1)

<Ref. to EN(H4SO)(diag)-156, DTC P0172 SYSTEM TOO RICH (BANK 1), 
Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0181

Fuel Temperature Sensor “A” Circuit 
Range/Performance

<Ref. to EN(H4SO)(diag)-158, DTC P0181 FUEL TEMPERATURE SENSOR 
“A” CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

P0182

Fuel Temperature Sensor “A” Circuit 
Low Input

<Ref. to EN(H4SO)(diag)-160, DTC P0182 FUEL TEMPERATURE SENSOR 
“A” CIRCUIT LOW INPUT, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0183

Fuel Temperature Sensor “A” Circuit 
High Input

<Ref. to EN(H4SO)(diag)-162, DTC P0183 FUEL TEMPERATURE SENSOR 
“A” CIRCUIT HIGH INPUT, Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P0196

Engine Oil Temperature Sensor Cir-
cuit Range/Performance

<Ref. to EN(H4SO)(diag)-164, DTC P0196 ENGINE OIL TEMPERATURE 
SENSOR CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P0197

Engine Oil Temperature Sensor Low

<Ref. to EN(H4SO)(diag)-166, DTC P0197 ENGINE OIL TEMPERATURE 
SENSOR LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0198

Engine Oil Temperature Sensor High

<Ref. to EN(H4SO)(diag)-168, DTC P0198 ENGINE OIL TEMPERATURE 
SENSOR HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0222

Throttle/Pedal Position Sensor/Switch 
“B” Circuit Low

<Ref. to EN(H4SO)(diag)-170, DTC P0222 THROTTLE/PEDAL POSITION 
SENSOR/SWITCH “B” CIRCUIT LOW, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0223

Throttle/Pedal Position Sensor/Switch 
“B” Circuit High

<Ref. to EN(H4SO)(diag)-172, DTC P0223 THROTTLE/PEDAL POSITION 
SENSOR/SWITCH “B” CIRCUIT HIGH, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0301

Cylinder 1 Misfire Detected

<Ref. to EN(H4SO)(diag)-173, DTC P0301 CYLINDER 1 MISFIRE 
DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0302

Cylinder 2 Misfire Detected

<Ref. to EN(H4SO)(diag)-173, DTC P0302 CYLINDER 2 MISFIRE 
DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0303

Cylinder 3 Misfire Detected

<Ref. to EN(H4SO)(diag)-173, DTC P0303 CYLINDER 3 MISFIRE 
DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0304

Cylinder 4 Misfire Detected

<Ref. to EN(H4SO)(diag)-174, DTC P0304 CYLINDER 4 MISFIRE 
DETECTED, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0327

Knock Sensor 1 Circuit Low (Bank 1 
or Single Sensor)

<Ref. to EN(H4SO)(diag)-180, DTC P0327 KNOCK SENSOR 1 CIRCUIT 
LOW (BANK 1 OR SINGLE SENSOR), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0328

Knock Sensor 1 Circuit High (Bank 1 
or Single Sensor)

<Ref. to EN(H4SO)(diag)-182, DTC P0328 KNOCK SENSOR 1 CIRCUIT 
HIGH (BANK 1 OR SINGLE SENSOR), Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

P0335

Crankshaft Position Sensor “A” Circuit <Ref. to EN(H4SO)(diag)-184, DTC P0335 CRANKSHAFT POSITION SEN-

SOR “A” CIRCUIT, Diagnostic Procedure with Diagnostic Trouble Code 
(DTC).>

P0336

Crankshaft Position Sensor “A” Circuit 
Range/Performance

<Ref. to EN(H4SO)(diag)-186, DTC P0336 CRANKSHAFT POSITION SEN-
SOR “A” CIRCUIT RANGE/PERFORMANCE, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P0340

Camshaft Position Sensor “A” Circuit 
(Bank 1 or Single Sensor)

<Ref. to EN(H4SO)(diag)-188, DTC P0340 CAMSHAFT POSITION SENSOR 
“A” CIRCUIT (BANK 1 OR SINGLE SENSOR), Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P0341

Camshaft Position Sensor “A” Circuit 
Range/Performance (Bank 1 or Single 
Sensor)

<Ref. to EN(H4SO)(diag)-190, DTC P0341 CAMSHAFT POSITION SENSOR 
“A” CIRCUIT RANGE/PERFORMANCE (BANK 1 OR SINGLE SENSOR), 
Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0400

Exhaust Gas Recirculation Flow

<Ref. to EN(H4SO)(diag)-192, DTC P0400 EXHAUST GAS RECIRCULATION 
FLOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>

P0420

Catalyst System Efficiency below 
Threshold (Bank 1)

<Ref. to EN(H4SO)(diag)-194, DTC P0420 CATALYST SYSTEM EFFICIENCY 
BELOW THRESHOLD (BANK 1), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>

DTC

Item

Reference