P324E on 2010-2015 Toyota Prius (Prius, Prius v, Prius Plug-in Hybrid) — MG ECU Power Relay Intermittent Circuit
1 vehicles · 1 makes · $2,500-$5,000 repair
Most Reported On
P324E is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 2010-2015 Toyota Prius (Prius, Prius v, Prius Plug-in Hybrid), with repair costs ranging from $2,500 to $5,000.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
P324E does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does P324E mean?
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.
What are the most common causes of P324E?
The most common causes of P324E are: 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. The specific cause varies by vehicle.
How much does it cost to fix P324E?
Repair costs for P324E range from $2,500 to $5,000, depending on the vehicle and root cause.
Which vehicles are affected by P324E?
Au7o has documented P324E across 1 vehicle models from 1 manufacturers: Toyota.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.