P0AE5 Code - Hybrid Battery Precharge Contactor Control Circuit Range/Performance
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
- P0AE5 indicates Hybrid Battery Precharge Contactor Control Circuit Range/Performance.
- 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.
Code P0AE5 Description
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.
What are the Possible Causes of the DTC P0AE5?
- 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 P0AE5?
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 P0AE5 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.
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Information for Specific Makes
- P0AE5 Lexus — Hybrid Battery Precharge Contactor Control Circuit Range/Performance
- P0AE5 Nissan — Hybrid Battery Precharge Contactor Control Circuit Range/Performance
- P0AE5 Toyota — Hybrid Battery Precharge Contactor Control Circuit Range/Performance
Frequently Asked Questions about P0AE5 Code
No Frequently Asked Questions about P0AE5 Code found.
Discuss the causes and fixes for P0AE5 OBDII Code
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P0AE5 on a 2017 Fusion Hybrid means the hybrid system is having trouble with the precharge circuit that safely connects the high-voltage battery to the rest of the system. The most common causes are a faulty system main relay, wiring/connectors to the relay, or in some cases the hybrid control module.
If the car still drives, pay attention to whether you are getting any "Stop Safely Now" messages, hybrid system warnings, or intermittent no-start conditions. Before replacing expensive components, I would inspect the relay connections and wiring for corrosion, loose terminals, or damage. On hybrids, a weak 12-volt battery can also cause strange control circuit faults, so make sure the 12V battery is in good condition.
Can you tell us what symptoms the Fusion is having besides the code? For example, does it start and drive normally, or are you getting hybrid system warnings on the dash? That information will help narrow down the cause.
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