P0AF5 — Drive Motor Inverter Temperature Sensor “B” Circuit High #

Note: The description for code P0AF5 may differ depending on the vehicle manufacturer (OEM). Always refer to your specific service manual for the most accurate wording.

• Toyota/Lexus: Drive Motor Inverter Temperature Sensor “B” Circuit High
• Chevrolet (GM): Drive Motor Inverter Temp Sensor “B” Range/Performance High
• Nissan: Inverter Temperature Sensor B Circuit High Input

Summary of DTC P0AF5 #

DTC P0AF5 points to an electrical issue detected in the circuit of the Drive Motor Inverter Temperature Sensor “B”. This sensor monitors the temperature of the inverter—a critical power electronics component that converts DC to AC for your hybrid or electric vehicle’s drive motor. When the sensor or its circuit reports a voltage higher than expected, the powertrain control module (PCM) or hybrid control module sets this code. Most commonly, this signals a fault in the sensor itself, its wiring, or—less frequently—a genuine overheating event. Prompt diagnosis is essential to prevent inverter damage and avoid unexpected vehicle behavior.

Common Symptoms for DTC P0AF5 #

When code P0AF5 appears, your vehicle may exhibit a range of symptoms, although some issues can be subtle. The inverter’s temperature sensor plays a key role in protecting critical power electronics, so any malfunction can trigger protective measures by the control system. Here’s what you might notice:

• Illuminated Check Engine Light or Hybrid System Warning
• Reduced Power Mode (also called “limp” or “fail-safe” mode)
• Decreased overall performance or acceleration
• High-voltage battery and/or inverter cooling fan running continuously
• Possible warning messages related to the hybrid or EV system
• Rarely, the vehicle may not start or may shut down unexpectedly

Most Probable Causes for Code P0AF5 #

Several issues can trigger a P0AF5 code, but some are far more common than others. Here’s a breakdown of the most likely root causes, in order of frequency:

1. Faulty drive motor inverter temperature sensor “B” (internal short/open or high resistance)
2. Damaged, corroded, or loose wiring/connectors at the sensor or inverter (especially signal or ground wires)
3. Connector contamination (moisture, dirt, corrosion)
4. Short circuit to power or open circuit in the sensor harness
5. Defective inverter assembly (rare, but possible if sensors and wiring check out)
6. PCM/Hybrid Control Module fault (very rare)

Step-by-Step Diagnostic for DTC P0AF5 #

Diagnosing P0AF5 involves methodical checks to rule out common issues before considering sensor or inverter replacement. Follow these steps:

• Verify the code with a professional scan tool and note freeze frame data (operating conditions when the code set).
• Visually inspect the inverter temperature sensor “B,” its connector, and wiring for damage, corrosion, or loose connections.
• Check for continuity and shorts in the sensor wiring harness using a digital multimeter. Test both signal and ground circuits.
• Measure sensor resistance (ohms) at ambient temperature and compare with OEM specs. An open or out-of-range value indicates sensor failure.
• Backprobe the sensor connector with the ignition on to verify voltage reference and signal return to the control module.
• Clear the code and road test the vehicle to see if the code reappears after repairs or connector resets.
• If all checks pass but the code persists, consider testing the inverter assembly or control module per OEM procedure.

Possible Repairs for DTC P0AF5 #

Once you’ve pinpointed the cause, effective repair will address the root problem. Here’s what may be needed, based on typical findings:

• Replace the inverter temperature sensor “B” if it tests out-of-spec or open/shorted
• Repair or replace damaged wiring or connectors (corrosion, bent pins, broken insulation, poor crimps)
• Clean connectors with electrical contact cleaner and ensure a tight fit
• Replace the inverter assembly only if internal sensor or circuit faults are confirmed and not serviceable separately
• Reprogram or replace the PCM/Hybrid Control Module only if all else fails and verified by OEM troubleshooting

Is It Safe to Drive with Code P0AF5? #

Limited—Not Recommended: While your vehicle may still operate with code P0AF5, it’s not advisable to continue driving for extended periods. The inverter temperature sensor protects key power electronics from overheating; without accurate readings, the system may enter reduced power mode or shut down to prevent catastrophic damage. There’s also a risk of unexpected loss of propulsion or a no-start condition. If this code appears, arrange for diagnosis and repair as soon as possible.

Vehicles Most Commonly Affected by DTC P0AF5 #

This code is most frequently reported on hybrid or electric vehicles from manufacturers who use inverter temperature sensors for power electronics protection. While not exclusive to any make, the following models are known to see P0AF5 relatively often:

• Toyota Prius (various generations)
• Lexus hybrid models (CT, RX, ES, GS)
• Chevrolet Volt, Spark EV
• Nissan Leaf and e-NV200
• Honda Clarity and Accord Hybrid (some years)
• Kia Niro Hybrid/EV, Hyundai Ioniq Hybrid/EV

Common Mistakes & Best Practices for P0AF5 Diagnosis #

Avoiding common pitfalls can save time and prevent unnecessary parts replacement. Here’s what technicians and DIYers should watch out for:

• Replacing the sensor without inspecting wiring—connector or harness issues are often to blame
• Overlooking corrosion or moisture intrusion at the connector, especially in humid or wet climates
• Ignoring technical service bulletins (TSBs) that may apply to your model/year
• Not following proper lockout/tagout or HV safety procedures when working near high-voltage components
• Clearing the code without fixing the root cause—the fault will almost always return

Quick FAQ for P0AF5 #

Can I reset the code myself?
Yes, you can clear the code with a scan tool, but if the underlying problem isn’t fixed, it will likely reappear. Always address the root cause.

Is this an expensive repair?
Costs vary widely: a simple connector fix or sensor replacement is usually affordable, but inverter or module replacement can be costly. Accurate diagnosis is key to avoid unnecessary expense.