LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2024 >> Impreza Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2.0L) (Diagnostics) - Introduction >> Fail Safe >> List
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fail Safe: List

NOTE: Depending on the driving environment and vehicle conditions at the time when a failure is detected, there may be a difference in how vehicle behavior feels due to failsafe control.
DTC Main failsafe operation Main vehicle behavior pattern Failsafe deactivation condition
P000A OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
Power reduction is felt compared to normal condition.
Noise is emitted.
After the condition returns to normal, turn to IG ON again.
P000B
P000C
P000D
P0010
P0011
P0013
P0014
P0016
P0017
P0018
P0019
P0020
P0021
P0023
P0024
P0030 CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Air fuel ratio feedback learning is stopped. Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
Gasoline odor may occur.
P0031 A/F correction value #1 is set to 0%.
Power to A/F sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Air fuel ratio feedback learning is stopped.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Gasoline odor may occur.
P0032
P0037 Power to oxygen sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.) A/F correction value #12 is set to 0%. -
P0038
P0068 Intake manifold absolute pressure is changed to intake air volume converted estimated value.
Number of EGR steps is set to 0 STEP.
ISC feedback air volume correction is set to 0 g/s (0 oz/s).
Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
Power reduction is felt compared to normal condition.
P0087 Fuel pressure is set to approx. 0.45 MPa. Power reduction is felt compared to normal condition.
Engine speed does not rise.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Engine starting performance becomes poor.
P0088
P0101 Load is changed to intake manifold pressure converted estimated value.
CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Gasoline odor may occur.
P0102
P0103
P0107 Number of EGR steps is set to 0 STEP.
Intake manifold absolute pressure is changed to intake air volume converted estimated value.
ISC feedback air volume correction is set to 0 g/s.
Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
Power reduction is felt compared to normal condition.
P0108
P0111 Intake air temperature is fixed to 20°C (68°F). Noise is emitted.
P0112
P0113
P0116 Radiator fan relay 1/radiator fan relay 2 is set to ON.
Coolant temperature is fixed to 70°C (158°F) for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
Active grille shutter drive instruction status is set to open.
TGV drive is fixed to closing direction.
OCV DUTY R/L is set to 0% and
intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0%
and exhaust VVT is stopped.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Radiator fan keeps rotating.
Engine starting performance becomes poor.
P0117
P0118
P0122 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg.
Fuel cut is performed according to the accelerator opening angle and engine speed.
Power reduction is felt compared to normal condition.
Engine speed does not rise.
P0123
P0125 Radiator fan relay 1/radiator fan relay 2 is set to ON.
Coolant temperature is fixed to 70°C (158°F) for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
TGV drive is fixed to closing direction.
OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
 
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Radiator fan keeps rotating.
Engine starting performance becomes poor.
P0131 A/F correction value #1 is set to 0%.
Power to A/F sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Air fuel ratio feedback learning is
stopped.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Gasoline odor may occur.
P0132
P0134
P0137 Power to oxygen sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.) A/F correction value #12 is set to 0%. -
P0138
P0140
P0141 A/F correction value #12 is set to 0%.
P014C CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
Gasoline odor may occur.
P0151 A/F correction value #1 is set to 0%.
Power to A/F sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Air fuel ratio feedback learning is stopped.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
P0152
P0153 CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
Gasoline odor may occur.
P0154 A/F correction value #1 is set to 0%.
Power to A/F sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Air fuel ratio feedback learning is stopped.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Gasoline odor may occur.
P0157 Power to oxygen sensor heater is set to OFF. (This cannot be confirmed on Subaru Select Monitor data monitor.) A/F correction value #12 is set to 0%. -
P0158
P015B CPC duty is set to 0%.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
Gasoline odor may occur.
P0172 CPC duty is set to 0%. Gasoline odor may occur.
P0191 High-pressure fuel pump is stopped.
(This cannot be confirmed on Subaru Select Monitor data monitor.)
Power reduction is felt compared to normal condition.
Engine speed does not rise.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Engine starting performance becomes poor.
P0192
P0193
P0196 Engine oil temperature is fixed to 70°C (158°F) for control purposes.
(This cannot be confirmed on Subaru Select Monitor data monitor.)
OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
Active grille shutter drive instruction status is set to open.
Power reduction is felt compared to normal condition.
Radiator fan keeps rotating.
P0197
P0198
P0222 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg.
Fuel cut is performed according to the accelerator opening angle and engine speed.
Power reduction is felt compared to normal condition.
Engine speed does not rise.
P0223
P0300 Number of EGR steps is set to 0 STEP.
Fuel injection for corresponding cylinder is stopped.
Power reduction is felt compared to normal condition.
Vibration easily occurs during idling.
P0301
P0302
P0303
P0304
P0327 Ignition timing #1 is set to maximum retard angle. Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
P0328
P0332
P0333
P0335 -
P0336 -
P0340 OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
Power reduction is felt compared to
normal condition.
Vehicle vibration easily occurs during
driving.
Noise is emitted.
P0341
P0345
P0346
P0365 Power reduction is felt compared to normal condition.
Noise is emitted.
P0366
P0390
P0391
P0400 OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
P0401
P0402
P0451 ELCM switching valve command is set to open. -
P0452 ELCM switching valve command is set to open.
Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
Noise is emitted.
Engine starting performance becomes poor.
P0453
P0500 Control is performed with vehicle speed set at 10 km/h (6.2 MPH) (displayed as 255 km/h (158.5 MPH) on Subaru Select Monitor data monitor).
Number of EGR steps is set to 0 STEP.
Radiator fan relay 1/radiator fan
relay 2 is set to ON.
Active grille shutter drive instruction
status is set to open.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Radiator fan keeps rotating.
P059A Active grille shutter drive instruction status is set to open. Radiator fan keeps rotating.
P05A0
P05A1
P05A2
P05A6
P05C0
P0604 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg. Power reduction is felt compared to normal condition.
Engine speed does not rise.
P0605
P0606
P060A
P060B
P0851 Fuel cut is performed at 4000 rpm.
P0852
P1160 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg.
P1235 High-pressure fuel pump is stopped.
(This cannot be confirmed on Subaru Select Monitor data monitor.)
Power reduction is felt compared to normal condition.
Engine speed does not rise.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Engine starting performance becomes poor.
P1449 Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Noise is emitted.
Gasoline odor may occur.
Engine starting performance becomes poor.
P1451 CPC duty is set to 0%. Gasoline odor may occur.
P1492 OCV DUTY R/L is set to 0% and intake VVT is stopped.
Exhaust OCV DUTY R/L is set to 0% and exhaust VVT is stopped.
Number of EGR steps is set to 0 STEP.
Power reduction is felt compared to normal condition.
P1493
P1494
P1495
P1496
P1497
P1498
P1499
P2004 TGV output duty is set to 12.5% and TGV drive is fixed to opening direction. Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
P2005
P2006 TGV output duty is set to 12.5% and TGV drive is fixed to closing direction. Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
P2007
P2008 TGV output duty is set to 0% and TGV drive is stopped.
P2009 TGV operation is restricted. Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
P2011 TGV output duty is set to 0% and TGV drive is stopped. Power reduction is felt compared to normal condition. Vehicle vibration easily occurs during driving.
P2012
P2016 TGV operation is restricted. Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
P2017
P2021
P2022
P2101 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg. Power reduction is felt compared to normal condition.
Engine speed does not rise.
P2102
P2109
P2119
P2122 Normal accelerator pedal position sensor is used alternatively until certain opening angle is reached.
BOS control is stopped.
Fuel cut is performed according to the accelerator opening angle and engine speed.
P2123
P2127
P2128
P2135 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg.
Fuel cut is performed according to the accelerator opening angle and engine speed.
P2138 Electronic throttle control is stopped and the actual throttle opening angle is fixed to about 22 deg.
Accelerator pedal opening angle is fixed to approx. 12%. BOS control is stopped.
BOS control is stopped.
Fuel cut is performed according to the accelerator opening angle and engine speed.
P2195 Generation voltage of generator is fixed to 14.5 V.
Battery current is fixed to 0 A, battery temperature to 20°C (68°F) and battery voltage to 14.3 V.
-
P2196
P2401 Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.) Noise is emitted.
Engine starting performance becomes poor.
P2419 Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
CPC duty is set to 0%.
Noise is emitted.
Gasoline odor may occur.
Engine starting performance becomes poor.
P24B9 ELCM switching valve command is set to open.
Atmospheric pressure is fixed to 1 bar for control purposes. (This cannot be confirmed on Subaru Select Monitor data monitor.)
Noise is emitted.
Engine starting performance becomes poor.
P24BA
P24BB
U0073 Torque value requested by driver is restricted.
Active grille shutter drive instruction status is set to open.
Auto Start Stop is prohibited.
Radiator fan relay 1/radiator fan relay 2 is set to ON.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Radiator fan keeps rotating.
Auto Start Stop does not operate.
U0077 Active grille shutter drive instruction status is set to open.
Generation voltage of generator is fixed to 14.5 V.
Battery current is fixed to 0 A, battery temperature to 20°C (68°F) and battery voltage to 14.3 V.
Radiator fan keeps rotating.
U0101 Torque value requested by driver is restricted.
Active grille shutter drive instruction status is set to open.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Radiator fan keeps rotating.
U0122 Torque value requested by driver is restricted.
Active grille shutter drive instruction status is set to open.
Control is performed with vehicle speed set at 10 km/h (6.2 MPH) (displayed as 255 km/h (158.5 MPH) on Subaru Select Monitor data monitor).
Number of EGR steps is set to 0 STEP.
Radiator fan relay 1/radiator fan relay 2 is set to ON.
Active grille shutter drive instruction status is set to open.
U0131 Active grille shutter drive instruction status is set to open. Radiator fan keeps rotating.
U0155 Active grille shutter drive instruction status is set to open.
Radiator fan relay 1/radiator fan relay 2 is set to ON.
Power reduction is felt compared to normal condition.
Radiator fan keeps rotating.
U01B0 Generation voltage of generator is fixed to 14.5 V.
Battery current is fixed to 0 A, battery temperature to 20°C (68°F) and battery voltage to 14.3 V.
-
U0284 Active grille shutter drive instruction status is set to open. Radiator fan keeps rotating.
U0402 Torque value requested by driver is restricted.
Active grille shutter drive instruction status is set to open.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Radiator fan keeps rotating.
U0416 Control is performed with vehicle speed set at 10 km/h (6.2 MPH) (displayed as 255 km/h (158.5 MPH) on Subaru Select Monitor data monitor).
Number of EGR steps is set to 0 STEP.
Radiator fan relay 1/radiator fan relay 2 is set to ON.
Active grille shutter drive instruction status is set to open.
Power reduction is felt compared to normal condition.
Vehicle vibration easily occurs during driving.
Vibration easily occurs during idling.
Radiator fan keeps rotating.
U0420 Active grille shutter drive instruction status is set to open. Radiator fan keeps rotating.
U0423 Active grille shutter drive instruction status is set to open.
Radiator fan relay 1/radiator fan relay 2 is set to ON.
Power reduction is felt compared to normal condition.
Radiator fan keeps rotating.