P2426 – Low Exhaust Gas Recirculation Cooler Control Valve Circuit

How severe is this DTC?

A stored P2426 code is related to the exhaust gas recirculation system. It should not be classified as severe.

What are some symptoms of the code?

Symptoms of a P2426 trouble code may include:

No symptoms (except stored code)
Increased cylinder temperature
Reduced energy efficiency
Exhaust temperature sensor codes
Engine temperature sensor codes

What are some common causes of the code?

Causes of this code may include:

Open or shorted EGR cooling valve control wires or connectors
Low coolant level
Faulty EGR temperature sensor(s)
Clogged EGR cooler
Engine overheating
Faulty EGR cooling fan

What are the troubleshooting steps for P2426?

The engine cooling system must be filled to the appropriate level with the proper coolant before proceeding. If there are engine coolant leaks or if the engine is overheating, it must be repaired before diagnosing the stored P2426.

A diagnostic scanner, digital volt/ohmmeter, vehicle information source, and infrared thermometer (with laser pointer) are some of the tools I would use to diagnose a P2426.

I might start with a visual inspection of the wiring harnesses and connectors associated with the EGR temperature sensor and ECT sensor. Harnesses that are near hot exhaust pipes and manifolds should be carefully examined.

Connect the scanner to the vehicle’s diagnostic port and retrieve all stored codes and relevant freeze frame data. Before clearing codes and testing the vehicle, I like to note this information in case it turns out to be an intermittent code.

At this point, two things happen: either the PCM enters readiness mode (with no stored codes), or the P2426 is reset.

If the PCM further enters a ready state, the P2426 is intermittent and will be more difficult to diagnose. In many cases, the condition will need to worsen before an accurate diagnosis can be made.

If the P2426 is reset, use the scanner’s data stream to observe EGR temperature sensor data and ECT sensor data. Restricting the scanner’s data stream to include only relevant information will produce a faster data response. If the scanner indicates that EGR temperature and ECT are within acceptable parameters, suspect a faulty PCM or PCM programming error. This is your least likely scenario.

If the EGR temperature sensor data or ECT sensor data is erratic or does not meet desired parameters, test the sensor(s) in question by following the test procedures and specifications located in your vehicle information source. Sensors that do not match manufacturer specifications should be considered faulty.

Use the DVOM to test the EGR cooling valve control circuit if the sensors are functioning properly. Remember to disconnect all associated controllers before testing. Repair or replace open or shorted circuits as needed.

If all EGR cooling valve control sensor circuits are intact, use the infrared thermometer to check the exhaust gas temperature at the EGR cooler (valve) inlet and at the EGR cooler outlet (with the engine running and at normal operating temperature). Compare your results with manufacturer specifications and replace faulty EGR cooling system components if necessary.

Installing high-performance aftermarket EGR parts and components may result in storing a P2426

P2427 – High Exhaust Gas Recirculation Cooler Control Valve Circuit

How severe is this DTC?

A stored P2427 code is related to the exhaust gas recirculation system. It should not be classified as severe.

What are some symptoms of the code?

Symptoms of a P2427 fault code may include:

No symptoms (except code storage)
Increased cylinder temperature
Reduced energy efficiency
Exhaust temperature sensor codes
Engine temperature sensor codes

What are some common causes of the code?

Causes of this code may include:

Open or shorted EGR cooling valve control wires or connectors
Low coolant level
Faulty EGR temperature sensor(s)
Clogged EGR cooler
Engine overheating
Faulty EGR cooling fan

What are the troubleshooting steps for P2427?

A diagnostic scanner, digital volt/ohmmeter, vehicle information source, and infrared thermometer (with laser pointer) are some of the tools I would use to diagnose a P2427.

At this point, one of two things happens: either the PCM enters readiness mode (with no stored codes), or the P2427 is reset.

If the PCM further enters a ready state, the P2427 is intermittent and will be more difficult to diagnose. In many cases, the condition will need to worsen before an accurate diagnosis can be made.

If the P2427 is reset, use the scanner’s data stream to observe EGR temperature sensor data and ECT sensor data. Restricting the scanner’s data stream to include only relevant information will produce a faster data response. If the scanner indicates that EGR temperature and ECT are within acceptable parameters, suspect a faulty PCM or PCM programming error. This is your least likely scenario.

If EGR temperature sensor data or ECT sensor data is erratic or does not meet desired parameters, test the sensor(s) in question by following the test procedures and specifications located in your vehicle information source. Sensors that do not match manufacturer specifications should be considered faulty.

Installing high-performance replacement parts and EGR components may result in storing a P2427

P2428 – Exhaust Gas Temperature Too High, Bank 1

P2428 Possible Causes

Faulty Exhaust Gas Temperature (EGT) sensor
Exhaust Gas Temperature (EGT) circuit wiring open or shorted
Poor electrical connection in Exhaust Gas Temperature (EGT) circuit
Extreme ambient temperature changes shortly after turning key ON, engine running

How to Fix Code P2428

Check the “Possible Causes” listed above. Visually inspect related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P2428 Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P2428 Meaning

The Powertrain Control Module (PCM) monitors the Exhaust Gas Temperature (EGT) sensor for a biased signal value. After an 8-hour soak, the PCM records the EGT sensor temperature value at key ON, engine OFF. After several minutes of vehicle operation at speeds above 40.2 km/h (25 mph), the PCM calculates an expected key ON, engine OFF value. The PCM determines what the expected EGT value at key ON, engine OFF should have been based on inputs from other sensors. The test fails when the difference between the expected calculated value and the actual recorded value is greater than 40°C (72°F).

P2429 – Exhaust Gas Temperature Too High, Bank 2

P2429 Possible Causes

Faulty Exhaust Gas Temperature (EGT)
Exhaust Gas Temperature (EGT) harness is open or shorted
Poor electrical connection in the Exhaust Gas Temperature (EGT) circuit
Extreme ambient temperature changes shortly after turning key ON, engine running

How to Fix Code P2429

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P2429

Symptoms

Possible

Illuminated engine light (or service engine soon warning light)

P2429 Meaning

P242A – Exhaust Gas Temperature Sensor Circuit, Bank 1 Sensor 3

The P242A code is related to an issue with the Exhaust Gas Temperature Sensor (EGTS), specifically the Bank 1, Sensor 3. This sensor plays an essential role in managing engine emissions by monitoring exhaust gas temperature and sending a signal to the Powertrain Control Module (PCM).

Explanation of Code P242A:

The Powertrain Control Module (PCM) monitors the Exhaust Gas Temperature Sensor (EGTS) to ensure it is functioning correctly and that temperature values are within expected ranges. This sensor is typically located near the Diesel Oxidation Catalyst (DOC) or the Diesel Particulate Filter (DPF). It detects exhaust gas temperature and sends a signal back to the PCM to control engine conditions, which helps reduce emissions. If this sensor sends incorrect values or if the sensor circuit has issues, the PCM triggers the P242A code.

Possible Causes of Code P242A:

Faulty Exhaust Gas Temperature Sensor (EGTS) (Bank 1, Sensor 3):
- The sensor may be defective or have an internal malfunction, preventing the PCM from receiving accurate temperature data.
Open or Shorted Sensor Circuit:
- A wire in the sensor circuit may be damaged, disconnected, or shorted, preventing proper exhaust gas temperature readings.
Poor Electrical Connection of the Sensor:
- The exhaust gas temperature sensor connectors may be corroded, loose, or have broken or bent pins, affecting signal communication.
Exhaust Leaks:
- Leaks in the exhaust system can disrupt gas temperature readings, skewing the data sent to the PCM.
Excessive Particulate Buildup on the Sensor:
- An accumulation of soot or particles from exhaust gases can clog the sensor and prevent it from accurately detecting temperature.

Symptoms Associated with Code P242A:

Check Engine Light illuminated.
Loss of engine performance or increased fuel consumption if emission management is affected.
Issues with Diesel Particulate Filter (DPF) regeneration, if the sensor is malfunctioning.
Malfunctioning emission management system due to incorrect sensor data.

Repair Steps for Code P242A:

Check the Exhaust Gas Temperature Sensor (EGTS):
- Inspect the temperature sensor (Bank 1, Sensor 3). If it is faulty, it may need to be replaced.
Check Electrical Connections:
- Inspect the connectors and wires associated with the sensor. Look for broken, bent, corroded pins or loose wires. If problems are detected, repair or replace the damaged components.
Check for Exhaust Leaks:
- Look for leaks in the exhaust system, especially around the temperature sensor. Exhaust leaks can disrupt temperature readings and must be repaired.
Clean or Replace the Sensor if Necessary:
- If the sensor is clogged with particles or soot, try to clean it thoroughly. If cleaning is not effective, replacing the sensor may be necessary.
Perform a Continuity Test:
- Use a multimeter to check the circuit continuity and ensure the sensor is functioning correctly.
Clear Error Codes:
- Once the repair is completed, clear the error codes using an OBD scanner and monitor the vehicle to check if the code reappears.

Recommended Repair:

If the temperature sensor is faulty, it should be replaced with a new one.
If exhaust leaks or wiring issues are identified, these should be repaired before resetting the codes.
A sensor cleaning may be attempted if particulate buildup is the cause of the problem.

P242B – Exhaust Gas Temperature Sensor Circuit Range/Performance, Bank 1 Sensor 3

P242B Possible Causes

Faulty Exhaust Gas Temperature Sensor (EGTS), Bank 1 Sensor 3
Exhaust Gas Temperature Sensor, Bank 1 Sensor 3 harness is open or short-circuited
Poor electrical connection in Bank 1 Sensor 3 circuit of the Exhaust Gas Temperature Sensor
Exhaust leaks
Excessive particulate buildup on the sensor

How to Fix Code P242B

Check the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P242B Possible Symptoms

Engine light on (or service engine soon warning light)

P242B Meaning

The Powertrain Control Module (PCM) continuously monitors the Exhaust Gas Temperature Sensor (EGTS) for proper circuit continuity and out-of-range high values. The EGTS is located in front of the Diesel Oxidation Catalyst (DOC) and/or in front of the Diesel Particulate Filter (DPF). The EGTS detects exhaust gas temperature and converts it to voltage, then sends it back to the PCM with the voltage signal to control engine conditions for effective emission reduction. The PCM sets the OBDII code P242B when the Exhaust Gas Temperature Sensor is outside factory specifications.

P242C – Low value in the exhaust gas temperature sensor circuit, bank 1 sensor 3

Code P242C: Causes, Symptoms, and Solutions

Code P242C is an OBD-II diagnostic trouble code related to the Exhaust Gas Temperature Sensor (EGTS) circuit. It indicates a performance range or signal out of specification issue for the Exhaust Gas Temperature Sensor, Bank 1, Sensor 3. This sensor plays a crucial role in emission management, particularly on diesel engines equipped with a Diesel Oxidation Catalyst (DOC) or a Diesel Particulate Filter (DPF).

Possible Causes of Code P242C

Faulty EGTS (Bank 1, Sensor 3).
Electrical Circuit Problem: Open circuit, short circuit, or damaged wiring.
Faulty Connections: Corrosion, bent pins, or loose connections on the connector.
Exhaust Leaks near the sensor or the aftertreatment system.
Sensor Fouling: Buildup of soot or particles disrupting the measurement.

Associated Symptoms

Illuminated Check Engine Light (or warning message).
Possible decrease in engine performance (depending on the severity of the fault).
Risk of increased fuel consumption or higher pollutant emissions.

EGTS Function

Located upstream of the DOC (Diesel Oxidation Catalyst) or DPF (Diesel Particulate Filter), the EGTS measures the exhaust gas temperature and converts it into an electrical signal (voltage) sent to the PCM (Powertrain Control Module). This data allows the PCM to:

Control DPF regenerations.
Optimize fuel dosing.
Limit pollutant emissions.

Code P242C is triggered when the PCM detects an abnormal voltage or inconsistency in the sensor values (e.g., unrealistic temperature).

Diagnostic and Repair Procedures

Visual Inspection:

Check the EGTS, its connector, and the wiring harness for damage, corrosion, or exposed wires.
Inspect the exhaust system for leaks.

Electrical Testing:

Use a multimeter to measure the sensor’s resistance and voltage (compare with manufacturer specifications).
Check for continuity and the absence of short circuits in the wiring.

Cleaning or Replacement:

Remove and clean the sensor if fouled (using an appropriate cleaner).
Replace the EGTS if faulty or out of specification.

Code Reset:

Clear the P242C code after repair using a diagnostic tool, then test drive the vehicle to confirm the issue is resolved.

Practical Tips

Specific Sensor: Always use a sensor compatible with your vehicle’s Bank 1, Sensor 3.
DOC/DPF: Inspect these components if the code persists, as severe fouling can distort measurements.
PCM Software: In rare cases, a PCM software update may be necessary.

For detailed instructions, refer to the manufacturer’s repair manual or consult a certified professional.

(Note: This code primarily concerns diesel vehicles equipped with emission aftertreatment systems.)

P242D – Exhaust Gas Temperature Sensor Circuit, Bank 1, Sensor 3

Meaning of Code P242D

Code P242D indicates a problem with the Exhaust Gas Temperature Sensor (EGTS) Bank 1 Sensor 3. This sensor plays a key role in:

🔥 Monitoring temperature before the DOC (Diesel Oxidation Catalyst) or DPF (Diesel Particulate Filter)
⚡ Transmitting data to the PCM to optimize combustion and DPF regeneration
🌍 Controlling pollutant emissions to comply with anti-pollution standards

A fault can lead to poor DPF regeneration management and increased pollutant emissions.

Possible Causes of Code P242D

1. EGTS Sensor Failure

Faulty sensor providing inconsistent values
Excessive soot deposits or physical damage

2. Electrical Problems

Cut or short-circuited wiring harness
Oxidized, loose, or corroded connector
Power supply or ground issue

3. Exhaust Leaks

Leak before the sensor skewing measurements
Damaged gaskets or pipes

4. Particle Accumulation

Severe sensor clogging from soot
DPF regeneration problem

Symptoms of Code P242D

🚨 Check engine light on (and possibly DPF light)
⚠ More frequent DPF regenerations or impossible regenerations
⛽ Increased fuel consumption
🐌 Loss of engine power (possible limp mode)
💨 Excessive exhaust smoke

Diagnosis and Repair of Code P242D

🔧 Required Tools:

Advanced OBD2 scanner (for real-time data)
Digital multimeter
Flashlight and inspection mirror
Sensor cleaner (if clogged)

📋 Diagnostic Procedure:

1. Visual Inspection

Check the condition of the sensor and its connector
Look for exhaust leaks before the sensor
Check for soot or deposit buildup on the sensor

2. EGTS Sensor Test

Measure the sensor’s resistance (compare to manufacturer specifications)
Check the supply voltage (typically 5V)
Compare temperature values with a scanner (should be plausible)

3. Electrical Circuit Check

Test continuity between the sensor and PCM
Look for short circuits or poor grounds

4. Corrective Solutions

Cleaning the sensor if clogged (with specific product)
Replacing the sensor if faulty
Repairing exhaust leaks
Replacing the wiring harness if damaged

Consequences of Not Repairing

🔥 Exhaust system overheating
💰 Costly damage to DPF or DOC
⚠ Exceeding pollutant emission limits
🚗 Engine entering limp mode

Conclusion

Code P242D signals a critical problem in the exhaust temperature monitoring system. Prompt action is necessary to:

Avoid damage to the DPF/DOC
Maintain engine performance
Comply with anti-pollution standards

⚠ Tip: If diagnosis is complex, consult a diesel systems specialist to avoid improper repairs.

➡ Is your vehicle showing this code? Describe your symptoms in the comments for personalized help!

P242E – Intermittent/Erratic Exhaust Gas Temperature Sensor Circuit, Bank 1, Sensor 3

P242E Possible Causes

Faulty Exhaust Gas Temperature Sensor (EGTS), Bank 1 Sensor 3
Exhaust Gas Temperature Sensor, Bank 1 Sensor 3 harness is open or short-circuited
Poor electrical connection in Bank 1 Sensor 3 circuit of the Exhaust Gas Temperature Sensor
Exhaust leaks
Excessive particulate buildup on the sensor

How to Fix Code P242E

P242E Possible Symptoms

Engine light on (or service engine soon warning light)

P242E Meaning

The Powertrain Control Module (PCM) continuously monitors the Exhaust Gas Temperature Sensor (EGTS) for proper circuit continuity and out-of-range high values. The EGTS is located in front of the Diesel Oxidation Catalyst (DOC) and/or in front of the Diesel Particulate Filter (DPF). The EGTS detects exhaust gas temperature and converts it to voltage, sending it back to the PCM with the voltage signal to control engine conditions for effective emission reduction. The PCM sets the OBDII code P242E when the exhaust gas temperature sensor is outside factory specifications.

P242F – Diesel Particulate Filter Restriction – Ash Accumulation

Explanation of Code P242F: “Diesel Particulate Filter (DPF) – Ash Accumulation”

Severity

Level : 🔴 High (risk of complete DPF clogging, engine damage, and major additional costs).
Urgency :
Significant power loss.
Risk of DPF failure (replacement cost: €800 to €3000).
Failure in technical inspection (excessive pollutant emissions).

Symptoms

🚗 Power loss (weak acceleration, especially uphill).
🌫️ Black smoke from the exhaust.
⚠️ Engine warning light on (MIL) and/or flashing DPF light.
🔥 High temperatures of the engine and exhaust.
⛽ Increased fuel consumption (up to +30%).

Main Causes

Excessive ash accumulation :

Origin : Unburned combustion residues (engine oil, poor-quality fuel).
Aggravating factors : Frequent short trips (prevent passive regeneration).

Regeneration system malfunction :

Interrupted active regeneration (e.g., engine shutdown during the process).
Faulty temperature sensor or defective lambda sensor.

Mechanical/electrical problems :

Faulty differential pressure sensor or clogged tubes.
Exhaust leaks (cracked manifold gaskets).
Faulty injectors (poor fuel atomization).

Diagnostic Procedure

Step 1: Reading OBD2 codes and data

Use a compatible diesel scanner (e.g., Autel DS808 or Launch X431) to:
Check differential pressures before/after DPF.
Analyze the ash counter (grams accumulated).

Step 2: Visual inspection

Check the pressure sensor tubes (detached, melted, or clogged).
Look for exhaust leaks (localized smoke, damaged gaskets).

Step 3: Differential pressure sensor test

Resistance measurement : Compare with manufacturer specifications (e.g., 4.6 kΩ at 20°C).
Vacuum test : Use a vacuum pump to check sensor responsiveness.

Step 4: Regeneration conditions check

Fuel level : Must be > 25% to initiate forced regeneration.
Coolant temperature : > 70°C.

Solutions & Costs

Solution	Procedure	Average Cost
Forced regeneration	Via scanner or dedicated button (depending on model)	€50 – €150 (garage)
Chemical DPF cleaning	Use of additives (e.g., Wynns DPF Cleaner)	€30 – €80
DPF replacement	Necessary if clogging > 90%	€800 – €3000
Pressure sensor replacement	New sensor + recalibration	€100 – €300
Exhaust leak repair	Replacement of gaskets/manifold	€200 – €600

Pro Tips

Avoid short trips : Prefer trips > 20 minutes at high RPM (2500-3000 rpm) to promote passive regeneration.
Use low-SAPS oils : Specific for diesel engines equipped with DPF (e.g., Total Quartz INEO ECS).
Monitor the ash counter : Via a scanner, trigger DPF replacement before 180,000 km (depending on manufacturer).

Mistakes to Avoid

❌ Ignoring the DPF light : Complete clogging can immobilize the vehicle.
❌ Forcing regeneration without diagnosis : Risk of overheating or fire.
❌ Using unapproved additives : Can damage catalysts.

Practical Case

Problem : Code P242F on a Peugeot 308 1.6 HDi with power loss.
Diagnosis : Ash counter at 45g (manufacturer limit: 40g).
Solution : Forced regeneration via scanner + cleaning of sensor tubes.

Frequently Affected Vehicles

Peugeot/Citroën : 308, 3008, 508, C4 Picasso.
Renault : Mégane, Scénic, Kadjar.
Ford : Focus, Kuga (1.5/2.0 TDCI engines).

Warnings

⚠️ Handling exhaust gases : Extreme temperatures (risk of burns).
⚠️ Professional repair recommended for forced regenerations or DPF replacements.

If the DPF is too clogged, regeneration alone will not suffice: consult a specialized garage to avoid engine damage! 🔧🚗