What Does P0A35 Mean?
DTC P0A35 indicates that hybrid drive motor "B" has exceeded its maximum allowable operating temperature threshold as monitored by the Hybrid Control Module. This is an actual over-temperature condition, not a sensor circuit fault, meaning the motor is genuinely overheating. The HCM will typically reduce motor power output or shut down the electric drive to prevent permanent damage to the motor windings, magnets, and insulation. Continued operation under overheating conditions can lead to irreversible demagnetization of permanent magnets and winding insulation breakdown.
Safety Warning
An overheating drive motor may cause sudden power loss or limp mode activation during driving, posing a safety risk in traffic. Prolonged overheating can cause permanent motor damage and potential fire risk in extreme cases.
Common Causes
30%
Restricted or failed electric motor coolant circulation (clogged lines, failing electric water pump)
25%
Low hybrid drivetrain coolant level due to leak
20%
Sustained high-load driving conditions (towing, steep grades, aggressive acceleration) beyond thermal capacity
15%
Faulty electric water pump for the motor cooling circuit
10%
Degraded thermal paste or heat transfer interface between motor and cooling jacket
Diagnostic Steps
1
Step 1: Check the hybrid drivetrain coolant level in the dedicated motor/inverter cooling circuit (separate from engine coolant on most hybrids). Top off if low and inspect for leaks.
2
Step 2: Verify operation of the electric water pump for the motor cooling circuit using scan tool active commands or by listening/feeling for pump operation with the key on.
3
Step 3: Use an infrared thermometer or thermal camera to check motor "B" surface temperature and compare to scan tool reported temperature to validate the sensor reading.
4
Step 4: Inspect coolant hoses and lines in the motor cooling circuit for kinks, blockages, or collapsed sections. Check the heat exchanger or radiator for the motor cooling loop for debris or blockage.
5
Step 5: Review driving conditions at the time of the fault via freeze frame data. If the overheating occurred only during extreme conditions, the system may be operating at its design limit and cooling upgrades or driving habit changes may be needed.
6
Step 6: If coolant system checks pass, the motor may have internal issues such as increased bearing friction or shorted windings drawing excessive current and generating abnormal heat. Measure motor insulation resistance and current draw.
Estimated Repair Cost
$200 - $2,500
Parts + labor, varies by vehicle and location
DTC P0A35 indicates that hybrid drive motor "B" has exceeded its maximum allowable operating temperature threshold as monitored by the Hybrid Control Module. This is an actual over-temperature condition, not a sensor circuit fault, meaning the motor is genuinely overheating. The HCM will typically r...
The most common cause of P0A35 (Drive Motor "B" Over Temperature) is: Restricted or failed electric motor coolant circulation (clogged lines, failing electric water pump)
Typical repair costs for P0A35 range from $200 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
An overheating drive motor may cause sudden power loss or limp mode activation during driving, posing a safety risk in traffic. Prolonged overheating can cause permanent motor damage and potential fire risk in extreme cases.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0A35 to identify the root cause.
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Quick Info
Category
Powertrain
System
Hybrid/EV Drivetrain
Difficulty
Type
Generic (SAE)
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