Subaru 2009 IMPREZA Service Manual page 1271

ENGINE (DIAGNOSTICS)
2. DRIVE CYCLE A — DRIVE THE VEHICLE WITH 80 KM/H (50 MPH) FOR 20 MINUTES, AND
THEN IDLE THE ENGINE FOR A MINUTE
DTC
Insufficient Coolant Temperature for Closed Loop Fuel
*P0125
Control
*P0126 Insufficient Engine Coolant Temperature for Stable Operation
Coolant Thermostat
*P0128 (Engine Coolant Temperature Below Thermostat Regulating
Temperature)
*P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
*P0171 System Too Lean (Bank 1)
*P0172 System Too Rich (Bank 1)
*P0301 Cylinder 1 Misfire Detected
*P0302 Cylinder 2 Misfire Detected
*P0303 Cylinder 3 Misfire Detected
*P0304 Cylinder 4 Misfire Detected
*P0420 Catalyst System Efficiency below Threshold (Bank 1)
*P0441 Evaporative Emission System Incorrect Purge Flow
Evaporative Emission Control System Leak Detected
*P0442
(Small Leak)
*P0451 Evaporative Emission Control System Pressure Sensor
Evaporative Emission Control System Leak Detected
*P0456
(Very Small Leak)
Evaporative Emission Control System Leak Detected
*P0457
(Fuel Cap Loose/Off)
Evaporative Emission System Purge Control Valve Circuit
*P0459
High
P1443 Vent Control Solenoid Valve Function Problem
*P2096 Post Catalyst Fuel Trim System Too Lean (Bank 1)
*P2097 Post Catalyst Fuel Trim System Too Rich (Bank 1)
3. DRIVE CYCLE B — 10 MINUTES IDLING
NOTE:
Drive the vehicle at 10 km/h (6 MPH) or faster before diagnosis.
DTC
*P0171 System Too Lean (Bank 1)
*P0172 System Too Rich (Bank 1)
*P0301 Cylinder 1 Misfire Detected
*P0302 Cylinder 2 Misfire Detected
*P0303 Cylinder 3 Misfire Detected
*P0304 Cylinder 4 Misfire Detected
*P0464 Fuel Level Sensor Circuit Intermittent
*P2096 Post Catalyst Fuel Trim System Too Lean (Bank 1)
*P2097 Post Catalyst Fuel Trim System Too Rich (Bank 1)
Drive Cycle
Item
Item
EN(H4DOTC)(diag)-50
Condition
Engine coolant temperature at engine start is less
than 20°C (68°F).
—
Engine coolant temperature at engine start is less
than 55°C (131°F).
—
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
—
—
Engine coolant temperature at engine start is less
than 25°C (77°F).
—
Engine coolant temperature at engine start is less
than 25°C (77°F).
Engine coolant temperature at engine start is less
than 25°C (77°F).
—
—
Complete diagnosis with drive cycle B or C as well.
Complete diagnosis with drive cycle B or C as well.
Condition
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.
—
Complete diagnosis with drive cycle A or C as well.
Complete diagnosis with drive cycle A or C as well.