AutoCodes – Generic – P0ADF

P0ADF Code - Hybrid Battery Negative Contactor Control Circuit Low

Quick Answer

The SMRs (System Main Relays) connect and disconnect the high-voltage power supply circuit in accordance with requests from the HV control ECU. Common causes include Faulty System Main Relay, System Main Relay harness is open or shorted, System Main Relay circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0ADF indicates Hybrid Battery Negative Contactor Control Circuit Low.
Common causes: Common causes include Faulty System Main Relay, System Main Relay harness is open or shorted, System Main Relay circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 4,066

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Feb 15, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0ADF Description

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.

OBDII Code P0ADF - Hybrid Battery Negative Contactor Control Circuit Low - AutoCodes.com — P0ADF Code - Hybrid Battery Negative Contactor Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0ADF?

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 DTC P0ADF?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0ADF code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0ADF code?

Need more information on how to fix the P0ADF code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0ADF code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0ADF Lexus — Hybrid Battery Negative Contactor Control Circuit Low
P0ADF Nissan — Hybrid Battery Negative Contactor Control Circuit Low
P0ADF Toyota — Hybrid Battery Negative Contactor Control Circuit Low

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0ADF Code

1. What does the OBDII code P0ADF mean?

Code P0ADF indicates an issue with the Hybrid Battery Negative Contactor Control Circuit, specifically that the circuit voltage is lower than expected.

2. What are the common symptoms of P0ADF?

Symptoms may include warning lights on the dashboard, reduced hybrid system performance, a failure to start the vehicle, or inability to charge the hybrid battery.

3. What causes the P0ADF code to appear?

Common causes include a faulty hybrid battery negative contactor, damaged wiring or connectors in the control circuit, or a malfunctioning hybrid battery control module.

4. Can I still drive my car with the P0ADF code?

It’s not recommended, as this issue can lead to further damage to the hybrid system and may result in the vehicle entering a limp mode or failing to start.

5. How is the P0ADF code diagnosed?

A technician will use an OBDII scanner to confirm the code, inspect the hybrid battery negative contactor and associated wiring, and test the control module for faults.

6. How do you fix the P0ADF code?

Repairs may include replacing the hybrid battery negative contactor, repairing damaged wiring or connectors, or replacing the hybrid battery control module if necessary.

7. How much does it cost to repair the P0ADF code?

Repair costs vary widely depending on the specific issue but can range from $200 for wiring repairs to over $1,000 for component replacement.

8. Can a weak hybrid battery cause the P0ADF code?

While a weak battery itself may not directly cause this code, it can contribute to voltage irregularities that trigger related electrical issues.

9. Does the P0ADF code affect fuel efficiency?

Yes, the code can reduce fuel efficiency by limiting the effectiveness of the hybrid system and forcing the vehicle to rely more on the internal combustion engine.

10. Will clearing the P0ADF code fix the issue?

Clearing the code may temporarily turn off the warning light, but the underlying problem must be resolved to prevent the code from returning.