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P040DModeratePowertrain

P040D: Exhaust Gas Recirculation Temperature Sensor "A" Circuit High

2 vehicles · 2 makes · $350-$1,500 repair

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Most Reported On

2010-2020Skoda OctaviaActive +52019-2025Toyota RAV4Hybrid LE +6

P040D is an OBD-II diagnostic trouble code meaning “Exhaust Gas Recirculation Temperature Sensor "A" Circuit High.” This code means the engine computer detected an abnormally high voltage on the circuit for EGR temperature sensor 'A'. This sensor measures the temperature of exhaust gases moving through the EGR system (often around the EGR cooler) to confirm the system is flowing and to protect components from overheating. A high-circuit reading usually points to a sensor or wiring problem rather than an actual overheat. It typically triggers the check engine light and may affect emissions and EGR operation. This code is most commonly reported on 2010-2020 Skoda Octavia (Active, Ambition, Elegance, Style, L&K, RS), and 2019-2025 Toyota RAV4 (Hybrid LE, Hybrid XLE, Hybrid XSE, Hybrid Limited, Hybrid Woodland, Prime SE, Prime XSE), with repair costs ranging from $350 to $1,500.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (2)
  • Related Codes
  • FAQ
  • Sources (2)

Makes

  • Skoda1
  • Toyota1
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Common Causes

1Faulty EGR temperature sensor (sensor A)
2Open circuit or broken wire in the sensor circuit
3Corroded, loose, or disconnected connector
4Wiring shorted to a high-reference voltage
5Poor sensor ground
6Failing PCM/ECM (rare)

Typical Repair Cost

$350 - $1,500

Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose P040D, you'll need an OBD-II scanner. Here are our recommendations at every price point.

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ANCEL AD310 Classic OBD-II Scanner

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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

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Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

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Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

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A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

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Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

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Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

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Vehicles Affected (2)

Skoda P040D page →
OctaviaCritical

2.0 TDI EGR Cooler Failure (Dieselgate-Era Engines)

2010-2020$500-$1,4000 reports
Toyota P040D page →
RAV4Moderate

Hybrid EGR Cooler/Valve Clogging and Coolant Leak on A25A-FXS 2.5L (White Smoke, Power Loss)

2019-2025$350-$1,5000 reports

Related Codes (8)

P0400Exhaust Gas Recirculation (EGR) Flow MalfunctionP0401Exhaust Gas Recirculation Flow InsufficientP0402Exhaust Gas Recirculation Flow ExcessiveP0403Exhaust Gas Recirculation Circuit MalfunctionP0013"B" Camshaft Position Actuator Circuit/Open (Bank 1)P0020Camshaft Position 'A' Actuator Circuit (Bank 2)P0023"B" Camshaft Position Actuator Circuit/Open (Bank 2)P0025"B" Camshaft Position - Timing Over-Retarded (Bank 2)

FAQ

What does P040D mean?

P040D stands for "Exhaust Gas Recirculation Temperature Sensor "A" Circuit High." This code means the engine computer detected an abnormally high voltage on the circuit for EGR temperature sensor 'A'. This sensor measures the temperature of exhaust gases moving through the EGR system (often around the EGR cooler) to confirm the system is flowing and to protect components from overheating. A high-circuit reading usually points to a sensor or wiring problem rather than an actual overheat. It typically triggers the check engine light and may affect emissions and EGR operation.

What are the most common causes of P040D?

The most common causes of P040D are: Faulty EGR temperature sensor (sensor A), Open circuit or broken wire in the sensor circuit, Corroded, loose, or disconnected connector, Wiring shorted to a high-reference voltage, Poor sensor ground, Failing PCM/ECM (rare). The specific cause varies by vehicle.

How much does it cost to fix P040D?

Repair costs for P040D range from $350 to $1,500, depending on the vehicle and root cause.

Which vehicles are affected by P040D?

Au7o has documented P040D across 2 vehicle models from 2 manufacturers: Skoda, Toyota.

Sources (2)

  • article2019-2024 Toyota RAV4 2.5L Hybrid Engine (A25A-FXS): Problems, Longevity, and Specs - EGR cooler leaks and valve clogging
  • manufacturerA25A-FXS (EMISSION CONTROL): EGR COOLER: REMOVAL; 2022-2025 MY RAV4 HV (Toyota repair manual)
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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