[SOLVED] P0Add Code: Fixing Hybrid Battery Negative Contactor Control Circuit/Open

The automobile fault code P0ADD indicates a problem with the System Main Relay. This can be identified by the Engine Light being ON or the Service Engine Soon Warning Light.

The cause of this fault code could be a faulty System Main Relay, an open or shorted harness, a poor electrical connection in the relay circuit, or a faulty HV control ECU. To fix this issue, you should visually inspect the wiring harness and connectors, checking for any damage or broken, bent, pushed out, or corroded pins in the connectors. The repair time for this issue is estimated to be 1.0.

To interpret the fault code, you can refer to the “Possible Causes” listed above.

Repair Importance Level10.0 (Out of 10)
Estimated Repair TimeApproximately 1.0 hour
Repair Difficulty Level10.0 (Out of 10)

When the engine light is on or the service engine soon warning light is illuminated, it could be a sign of the p0add fault code.

  • The symptoms of the automobile fault code p0add include the Engine Light being ON or the Service Engine Soon Warning Light being illuminated.

The automobile fault code p0add can be caused by a faulty System Main Relay, an open or shorted System Main Relay harness, a poor electrical connection in the System Main Relay circuit, or a faulty HV control ECU.

  • The fault code p0add can be caused by the following: a faulty System Main Relay, an open or shorted System Main Relay harness, a poor electrical connection in the System Main Relay circuit, and a faulty HV control ECU.

To fix the automobile fault code p0add, start by visually inspecting the wiring harness, connectors, and components for any damage or corrosion.

  • To fix the automobile fault code p0add, first, check the possible causes mentioned above.
  • Then, visually inspect the wiring harness and connectors related to the issue.
  • Look for any damaged components and check if there are any broken, bent, pushed out, or corroded pins in the connectors.
  • This fix is estimated to take approximately 1.0 hour.

The fault code P0ADD is associated with the hybrid system drive motor A position sensor circuit. The estimated repair time for this issue is 1.0 hour.

Auto repair shops typically charge between $75 and $150 per hour for this type of repair.

The P0ADD fault code refers to a problem with the Hybrid Battery Negative Contactor Control CircuitO. The SMRs (System Main Relays) are responsible for connecting and disconnecting the high-voltage power supply circuit as requested by the HV control ECU.

To ensure reliable operation, there are 3 relays in total – 1 for the negative side and 2 for the positive side. When connecting, SMR1 and SMR3 turn ON initially, followed by SMR2 turning ON and SMR1 turning OFF.

This process protects the circuit from high-voltage surge current by allowing the limit current to flow via the resistor. When disconnecting, 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 any malfunction.

What are the possible causes of the automobile fault code P0ADD?

If you see the engine light or service engine soon warning light on, it could be due to the fault code P0ADD. This code is often caused by a faulty system main relay, an open or shorted relay harness, a poor electrical connection in the relay circuit, or a faulty HV control ECU. To fix this issue, you should visually inspect the wiring harness and connectors, checking for any damage or corrosion. Additionally, look out for broken, bent, pushed out, or corroded pins in the connectors.

How can I visually inspect the wiring harness and connectors to fix the P0ADD fault code?

To fix the P0ADD fault code, start by visually inspecting the wiring harness and connectors. Look for any damaged components and check if there are any broken, bent, pushed out, or corroded pins in the connectors. This can help identify any issues with the System Main Relay or its circuit. Don’t forget to check the other possible causes mentioned, such as a faulty System Main Relay or poor electrical connection.

What should I look for when checking for damaged components and connector pins to resolve the P0ADD fault code?

When resolving the P0ADD fault code, start by checking for damaged components and connector pins. This can be done by visually inspecting the related wiring harness and connectors. Look for any broken, bent, pushed out, or corroded pins on the connectors. By doing this, you can identify any issues that may be causing the fault code and take the necessary steps to fix them.

p0add error fault code explained

If your engine light is on or you see the service engine soon warning light, it could be due to a faulty system main relay or issues with the relay harness and circuit. To fix it, visually inspect the wiring harness and connectors, checking for any damage or corrosion. Look out for broken or bent pins on the connectors.

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