Engine-Codes - Generic - P0AA4

P0AA4 Code - Hybrid Battery Negative Contactor Circuit Stuck Closed

- Code Popularity: 7,849 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents

|What are the Possible Causes of the P0AA4 Code?

  • Faulty System Main Relay
  • System Main Relay harness is open or shorted
  • System Main Relay circuit poor electrical connection
  • Faulty HV control ECU

|How to Fix the P0AA4 Code?

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 P0AA4 code?

Labor: 1.0

The cost to diagnose the P0AA4 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|What are P0AA4 code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|What Does the P0AA4 Code Mean?

The 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.

Hybrid Battery Negative Contactor Circuit Stuck Closed

|Need more information with the P0AA4 code?

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|P0AA4 code information for specific makes

  • P0AA4 BUICK Hybrid/EV Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 CADILLAC Hybrid/EV Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 CHEVROLET Hybrid/EV Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 GMC Hybrid/EV Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 LEXUS Hybrid Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 NISSAN Hybrid Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 SATURN Hybrid/EV Battery Negative Contactor Circuit Stuck Closed
  • P0AA4 TOYOTA Hybrid Battery Negative Contactor Circuit Stuck Closed

|Need help with a P0AA4 code?

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