P324E on Toyota
MG ECU Power Relay Intermittent Circuit
P324E on Toyota vehicles indicates mg ecu power relay intermittent circuit. Au7o has documented this code across 1 Toyota model — most commonly on Prius. The MG ECU, which lives inside the inverter with converter assembly and controls the motor-generators, lost and regained its power source. When the MG ECU resets because of a problem with the power supply inside the inverter, the power management control ECU records P324E. It is an intermittent power-supply fault, not a motor fault. Toyota bulletin T-SB-0036-16 lists P324E (sub-code 788) alongside P0A94, P0A1A, and P3004 as inverter-assembly malfunctions on 2010-2014 Prius and 2012-2014 Prius v, and the prescribed repair for the P324E path is replacement of the IPM transistor and the MG ECU. Toyota's later IPM programs extend coverage where the IPM failed from a thermal event. Typical repair costs on Toyota range from $2,500 to $5,000, depending on the specific model and root cause.
Common Causes of P324E
- •Intelligent Power Module (IPM) failure inside the inverter, often thermally induced
- •MG ECU (MG control computer sub-assembly) internal fault
- •Loss or interruption of the MG ECU power supply inside the inverter with converter assembly
- •Inverter internal connector or solder-joint degradation
P324E on Toyota by Model
Toyota Prius(1 issue)
- Inverter Intelligent Power Module (IPM) Overheating and Hybrid System Stall2010-2015
Transistors inside the Intelligent Power Module of the inverter/converter assembly can overheat and fail under sustained high load (long grades, hard acceleration, hot weather). When the module faults, the hybrid system shuts down and the car can stall at speed, sometimes without warning. Toyota first issued a software recall to reduce IPM thermal stress (NHTSA 14V-053, ~701,000 US Gen 3 cars), later expanded remedies (18V-684), and created Customer Support Program ZE3 extending inverter coverage on 2010-2014 Prius to 15 years/unlimited miles. Owners report stalls persisting after the software remedy, which drove follow-on litigation. This is failure of the inverter itself - distinct from the inverter coolant pump.
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View P324E across all makes →Frequently Asked Questions
What does P324E mean on Toyota?▼
P324E stands for "MG ECU Power Relay Intermittent Circuit." The MG ECU, which lives inside the inverter with converter assembly and controls the motor-generators, lost and regained its power source. When the MG ECU resets because of a problem with the power supply inside the inverter, the power management control ECU records P324E. It is an intermittent power-supply fault, not a motor fault. Toyota bulletin T-SB-0036-16 lists P324E (sub-code 788) alongside P0A94, P0A1A, and P3004 as inverter-assembly malfunctions on 2010-2014 Prius and 2012-2014 Prius v, and the prescribed repair for the P324E path is replacement of the IPM transistor and the MG ECU. Toyota's later IPM programs extend coverage where the IPM failed from a thermal event. On Toyota specifically, this code is documented across 1 model.
What causes P324E on Toyota vehicles?▼
Common causes on Toyota: Intelligent Power Module (IPM) failure inside the inverter, often thermally induced, MG ECU (MG control computer sub-assembly) internal fault, Loss or interruption of the MG ECU power supply inside the inverter with converter assembly, Inverter internal connector or solder-joint degradation. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P324E on a Toyota?▼
Repair costs on Toyota range from $2,500 to $5,000, depending on the specific model and root cause.
Which Toyota models have P324E documented?▼
Au7o has documented P324E on 1 Toyota model: Prius.