P0AA1 TOYOTA - Hybrid Battery Positive Contactor Circuit Stuck Closed
P0AA1 TOYOTA Possible Causes
- Faulty System Main Relay
- System Main Relay harness is open or shorted
- System Main Relay circuit poor electrical connection
- Faulty HV control ECU
How is the P0AA1 TOYOTA code repair?Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
What is the cost to diagnose the P0AA1 TOYOTA code
Labor: 1.0The cost to diagnose the P0AA1 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
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- Engine Light ON (or Service Engine Soon Warning Light)
P0AA1 TOYOTA MeaningThe SMRs (System Main Relays) connect and disconnect the high-voltage power supply circuit in accordance with requests from the HV control ECU. To ensure a reliable operation, they consists of a total of 3 relays (1 for the negative side and 2 for the positive side).
To connect, SMR1 and SMR3 turn ON initially. Then, SMR2 turns ON and SMR1 turns OFF. This process protects the circuit from the high-voltage surge current by allowing the limit current to flow via the resistor. To disconnect, SMR2 and SMR3 turn OFF in that order. The HV control ECU checks that the relays have turned OFF properly.
The HV control ECU monitors the proper operation of the SMRs (CON1, CON2 and CON3) to check for a malfunction.
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