STOP AND START SYSTEM > FAIL-SAFE CHART


If any of the following DTCs are stored, the engine stop and start ECU enters fail-safe mode to preserve vehicle operability.

DTC
Component
Fail-safe Operation
Fail-safe Deactivation Condition
P0335
Open in engine speed signal circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
All of the following conditions continue for 10 seconds:
  1. Normal communication with ECM
  2. Engine speed (pulse signal) 500 rpm or more
  3. Engine speed (communication signal) 500 rpm or more
  4. Difference between engine speed via pulse signal and engine speed via communication signal is less than 100 rpm
P0500
Vehicle speed circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Vehicle speed (pulse signal) 10 km/h (6.2 mph) or more
P0562
  1. Generator circuit
  2. Low battery voltage
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Both of the following conditions continue for at least 3 seconds while the engine is stopped due to Stop and Start system control and the generator is not generating electricity:
  1. +B voltage 11 V or more
  2. Engine stopped
P062F
Engine stop and start ECU
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
A/C information and the number of starter operations have been successfully registered
P1540
Vacuum sensor assembly circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Sensor output is within standard range
P1541
  1. Vacuum sensor assembly
  2. Vacuum sensor assembly circuit
  3. Brake booster assembly
  4. Brake booster hose
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Either of the following conditions is met:
  1. Vacuum changes while the brake pedal is depressed
  2. There is a specified number of times that vacuum changes while the vehicle is driven faster than a certain vehicle speed
P1545
  1. Starter assembly
  2. Starter circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
  1. The number of starter operations stored in the ECU is cleared (after the starter is replaced)
  2. Communication with ECM returns to normal and one of the following conditions (a) or (b) is met:
    1. When ECM STA is ON, starter signal is ON (determined if it remains ON for 0.3 seconds)
    2. When ECM STA is OFF, starter signal is OFF (determined if it remains OFF for 5 seconds)
P1644
  1. Starter drive circuit
  2. ST relay
  3. Engine stop and start ECU (STA circuit)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
The voltage conditions in the ECU internal drive circuit for starter are correctly recognized when the engine is idling and restarted
P1862
  1. Clutch start switch (lower)
  2. Clutch switch (upper)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Clutch pedal switches (upper and lower) remain off for 0.5 seconds
P2531
Ignition switch circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
All of the following conditions continue for at least 10 seconds:
  1. Ignition switch ON
  2. Normal communication with ECM
P323B
  1. Backup boost converter
  2. Backup boost converter circuit
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
DTCs are cleared by disconnecting the battery or using the intelligent tester
U0100
CAN communication (ECM)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 1.52 seconds
U0121
CAN communication (ABS/VSC)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 4.8 seconds
U0131
CAN communication (EPS)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 1.6 seconds
U0140
CAN communication (main body ECU)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 7.2 seconds
U0151
CAN communication (center airbag sensor)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 21.2 seconds
U0155
CAN communication (meter)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 21.2 seconds
U0164
CAN communication (A/C)
  1. Stop and Start system control is prohibited
  2. Engine is automatically restarted if a DTC is stored while the engine is stopped due to Stop and Start system control
Communication with engine stop and start ECU continues for 21.2 seconds