TOYOTA CAMRY,
LEXUS & PRIUS
TROUBLESHOOTING CODES
While Toyota Camry Hybrids, Lexus Hybrids, and Priuses share similar hybrid technology, each model may have specific fault codes. However, many common codes apply to these vehicles. Here’s a detailed breakdown to help you understand and troubleshoot potential issues:
P0A81–P0A85: Battery Cooling Fan Issues
Possible Symptoms:
- Warning light for hybrid system
- Reduced engine performance
- Overheating of hybrid battery
- Increased fan noise
Possible Causes:
- Malfunctioning battery cooling fan
- Clogged or blocked fan duct
- Faulty fan control circuit
- Wiring harness damage
P0A93: Inverter Cooling System Performance
Possible Symptoms:
- “Check Hybrid System” warning
- Vehicle stalling or going into limp mode
- No A/C performance (in some models)
- Overheating of inverter or engine
Possible Causes:
- Failed inverter water pump
- Low or contaminated inverter coolant
- Air trapped in cooling system
- Faulty inverter temperature sensor
P0A94: DC/DC Converter Performance
Possible Symptoms:
- Dashboard warning lights
- Power loss or failure to start
- Inconsistent 12V accessory operation
- Charging issues for 12V battery
Possible Causes:
- Malfunction in DC/DC converter circuit
- Faulty inverter/converter assembly
- Voltage fluctuations from hybrid system
- Wiring or grounding issue
P0A0F: Engine Failed to Start
Possible Symptoms:
- Engine cranks but doesn’t start
- Vehicle runs on EV mode only
- Warning lights on dashboard
- Engine shuts off suddenly
Possible Causes:
- Weak or dead 12V battery
- Faulty fuel system (injectors, pump)
- Hybrid battery below starting threshold
- Inverter or ignition system failure
P1A10: Battery Voltage Fault
Possible Symptoms:
- Check hybrid battery light on
- Loss of electric-only driving capability
- Poor acceleration
- System shuts down intermittently
Possible Causes:
- Imbalance in battery cells
- Overcharged or undercharged cells
- Battery ECU sensor error
- Faulty battery module
C1241: Low Battery Positive Voltage
Possible Symptoms:
- Multiple warning lights triggered
- ABS or VSC not functioning
- Radio and accessories reset
- Vehicle may not start
Possible Causes:
- Multiple warning lights triggered
- ABS or VSC not functioning
- Radio and accessories reset
- Vehicle may not start
C1259 & C1310: HV System Malfunctions
Possible Symptoms:
- Brake system warning light
- “Check Hybrid System” warning
- Regenerative braking not functioning
- Poor fuel efficiency
Possible Causes:
- HV ECU detecting hybrid malfunction
- Regenerative brake system fault
- Communication error between ECUs
- HV battery or inverter issue
P0A0D: High Voltage System Interlock Circuit High
Possible Symptoms:
- Warning lights on the dashboard (e.g., Check Engine light, hybrid system warning light)
- Reduced power or inability to start the car
- In some cases, no noticeable symptoms
Possible Causes:
- Short circuit in the high voltage system wiring
- Faulty high voltage system contactor
- Inverter or other high voltage system component malfunction
P0A7F: Hybrid Battery Pack Deterioration
Possible Symptoms:
- Reduced fuel efficiency
- Decreased power output, especially during acceleration
- Difficulty maintaining battery charge
- In some cases, no noticeable symptoms
Possible Causes:
- Age and wear of the hybrid battery pack
- Excessive heat exposure
- Frequent shallow discharges (not fully depleting the battery)
P0A80: Replace Hybrid Battery Pack
Possible Symptoms:
- All symptoms listed for P0A7F (reduced fuel efficiency, decreased power, etc.)
- The car may go into limp mode (reduced power) to protect itself
- In some cases, no noticeable symptoms
Possible Causes:
- Severe degradation or failure of the hybrid battery pack
- Multiple cell failures within the battery
- Internal short circuits or other critical issues
P3000-P3024: Battery Block Voltage System Malfunction
Possible Symptoms:
- Reduced fuel efficiency
- Decreased power output
- Erratic engine or hybrid system behavior
- Warning lights on the dashboard
Possible Causes:
- Faulty or damaged individual battery block
- Corrosion or loose connections within the battery pack
- Internal cell imbalances within the battery
P0AA6: Hybrid Battery Voltage System Isolation Fault
Possible Symptoms:
- Warning lights on the dashboard (e.g., Check Engine light, hybrid system warning light)
- The car may go into limp mode (reduced power) to protect itself
- In some cases, no noticeable symptoms (but still a critical safety concern)
Possible Causes:
- Damage to the high-voltage system insulation
- Malfunction of the isolation contactor
- Internal inverter or other high-voltage component failure
P3011-P3024: Battery Block Voltage System
Possible Symptoms:
- Reduced fuel efficiency
- Decreased power output, especially during acceleration
- Erratic engine or hybrid system behavior
- Warning lights on the dashboard (e.g., Check Engine light, hybrid system warning light)
Possible Causes:
- Faulty or damaged specific battery block indicated by the code (e.g., P3011 points to block 1, P3012 to block 2, and so on)
- Corrosion or loose connections within the specific battery block
- Internal cell imbalances within the specific battery block
P3004: HV Battery Voltage Sense Line
Possible Symptoms:
- Inaccurate state of charge (SOC) display
- Sudden drop in hybrid performance
- Check hybrid system warning
- Engine running more frequently
Possible Causes:
- Damaged voltage sensing wire
- Faulty battery monitoring sensor
- Corroded connector or plug
- Intermittent contact in harness