Exhaust Gas Recirculation Valves and Sensors

Exhaust Gas Recirculation Valves

The Exhaust Gas Recirculation Valve, also referred to as EGR, meters the exhaust gas that is being recirculated into the intake manifold. This exhaust gas recirculation process reduces combustion chamber temperatures, resulting in reduced NOx emissions.

Common causes of Exhaust Gas Recirculation Valve failure include:

Valve gets stuck in the closed or open position due to a build-up of dirt, debris, or carbon
Clogged catalytic converter
Electrical issues with the valve control unit
Intake leaks
Incorrect vacuum hose connection
Damaged or missing EGR valve gasket
Issues with the vacuum control or switching valve
Defective EGR solenoid

Symptoms of a failing Exhaust Gas Recirculation Valve may include:

Difficult starts
Engine surging
Rough idle or stalls when idling
Reduced fuel efficiency
Fuel odor
Knocking noises coming from the engine
Check Engine Light on

The following OBD II error codes are the most commonly found with this product type. In an effort to reduce vehicle emissions, the Environmental Protection Agency (EPA), mandated that all vehicles manufactured after 1996 would be equipped with OBD II (On Board Diagnostics 2) technology. OBD II is now the standard in diagnosing vehicle emissions, which was implemented by all automotive manufacturers in 1996. The codes listed for this product type are common instances that may relate to your vehicle and should be used as a guide only. Walker Products will not be held responsible for any use of this information. It is highly suggested that you consult with a professionally trained mechanic prior to any automotive repair, and that you follow all vehicle manufacturer and EPA guidelines for removal, replacement, diagnostics, OBD II code clearing, ECU, and PCM relearn procedures.

o P2BAB nox Exceedence – Incorrect EGR Flow
o P2BAC nox Exceedence – Deactivation of EGR
o P0400 Exhaust Gas Recirculation “A” Flow
o P0401 Exhaust Gas Recirculation “A” Flow Insufficient Detected
o P0402 Exhaust Gas Recirculation “A” Flow Excessive Detected
o P0403 Exhaust Gas Recirculation “A” Control Circuit
o P0404 Exhaust Gas Recirculation “A” Control Circuit Range/Performance
o P0405 Exhaust Gas Recirculation Sensor “A” Circuit Low
o P0406 Exhaust Gas Recirculation Sensor “A” Circuit High
o P0407 Exhaust Gas Recirculation Sensor “B” Circuit Low
o P0408 Exhaust Gas Recirculation Sensor “B” Circuit High
o P0409 Exhaust Gas Recirculation Sensor “A” Circuit
o P040A Exhaust Gas Recirculation Temperature Sensor “A” Circuit
o P040B Exhaust Gas Recirculation Temperature Sensor “A” Circuit
o P040C Exhaust Gas Recirculation Temperature Sensor “A” Circuit Low
o P040D Exhaust Gas Recirculation Temperature Sensor “A” Circuit High
o P040E Exhaust Gas Recirculation Temperature Sensor “A” Circuit
o P040F Exhaust Gas Recirculation Temperature Sensor “A”/”B” Correlation
o P041A Exhaust Gas Recirculation Temperature Sensor “B” Circuit
o P041B Exhaust Gas Recirculation Temperature Sensor “B” Circuit
o P041C Exhaust Gas Recirculation Temperature Sensor “B” Circuit Low
o P041D Exhaust Gas Recirculation Temperature Sensor “B” Circuit High
o P041E Exhaust Gas Recirculation Temperature Sensor “B” Circuit
o P042E Exhaust Gas Recirculation “A” Control Stuck Open
o P042F Exhaust Gas Recirculation “A” Control Stuck Closed
o P044A Exhaust Gas Recirculation Sensor “C” Circuit
o P044B Exhaust Gas Recirculation Sensor “C” Circuit Range/Performance
o P044C Exhaust Gas Recirculation Sensor “C” Circuit Low
o P044D Exhaust Gas Recirculation Sensor “C” Circuit High
o P044E Exhaust Gas Recirculation Sensor “C” Circuit Intermittent/Erratic
o P045A Exhaust Gas Recirculation “B” Control Circuit
o P045B Exhaust Gas Recirculation “B” Control Circuit Range/Performance
o P045C Exhaust Gas Recirculation “B” Control Circuit Low
o P045D Exhaust Gas Recirculation “B” Control Circuit High
o P045E Exhaust Gas Recirculation “B” Control Stuck Open
o P045F Exhaust Gas Recirculation “B” Control Stuck Closed
o P046C Exhaust Gas Recirculation Sensor “A” Circuit Range/Performance
o P046D Exhaust Gas Recirculation Sensor “A” Circuit Intermittent/Erratic
o P046E Exhaust Gas Recirculation Sensor “B” Circuit Range/Performance
o P046F Exhaust Gas Recirculation Sensor “B” Circuit Intermittent/Erratic
o P0486 Exhaust Gas Recirculation Sensor “B” Circuit
o P0487 Exhaust Gas Recirculation Throttle Control Circuit “A” /Open
o P0488 Exhaust Gas Recirculation Throttle Control Circuit “A”
o P0489 Exhaust Gas Recirculation “A” Control Circuit Low
o P0490 Exhaust Gas Recirculation “A” Control Circuit High
o P049A Exhaust Gas Recirculation “B” Flow
o P049B Exhaust Gas Recirculation “B” Flow Insufficient Detected
o P049C Exhaust Gas Recirculation “B” Flow Excessive Detected
o P049D Exhaust Gas Recirculation “A” Control Position Exceeded Learning
o P049E Exhaust Gas Recirculation “B” Control Position Exceeded Learning
o P213A Exhaust Gas Recirculation Throttle Control Circuit “B” /Open
o P213B Exhaust Gas Recirculation Throttle Control Circuit “B”
o P213C Exhaust Gas Recirculation Throttle Control Circuit “B” Low
o P213D Exhaust Gas Recirculation Throttle Control Circuit “B” High
o P2141 Exhaust Gas Recirculation Throttle Control Circuit “A” Low
o P2142 Exhaust Gas Recirculation Throttle Control Circuit “A” High
o P2143 Exhaust Gas Recirculation Vent Control Circuit/Open
o P2144 Exhaust Gas Recirculation Vent Control Circuit Low
o P2145 Exhaust Gas Recirculation Vent Control Circuit High
o P2413 Exhaust Gas Recirculation System Performance
o P2425 Exhaust Gas Recirculation Cooling Valve Control Circuit/Open
o P2426 Exhaust Gas Recirculation Cooling Valve Control Circuit Low
o P2427 Exhaust Gas Recirculation Cooling Valve Control Circuit High
o P2457 Exhaust Gas Recirculation Cooling System Performance
o P245A Exhaust Gas Recirculation Cooler Bypass Control Circuit/Open
o P245B Exhaust Gas Recirculation Cooler Bypass Control Circuit
o P245C Exhaust Gas Recirculation Cooler Bypass Control Circuit Low
o P245D Exhaust Gas Recirculation Cooler Bypass Control Circuit High
o U010A Lost Communication With Exhaust Gas Recirculation Control Module
o U010B Lost Communication With Exhaust Gas Recirculation Control Module
o U040B Invalid Data Received From Exhaust Gas Recirculation Control
o U040C Invalid Data Received From Exhaust Gas Recirculation Control

Exhaust Gas Recirculation Valve Position Sensors

The Exhaust Gas Recirculation Valve Position Sensor, or EVP, monitors the EGR valve position by sending varying voltages to the vehicle’s onboard computer, also known as an Engine Control Unit (ECU) or Powertrain Control Module (PCM). The computer then uses this information along with input from other sensors to determine the correct amount of exhaust gas to properly control emissions.

Common causes of Exhaust Gas Recirculation Valve Position sensor failure:
• Clogged EGR Valve

Symptoms of a failing Exhaust Gas Recirculation Valve Position sensor may include:
• Rough idle
• Engine surging
• Check Engine Light on

o P0404 Exhaust Gas Recirculation “A” Control Circuit Range/Performance
o P0405 Exhaust Gas Recirculation Sensor “A” Circuit Low
o P0406 Exhaust Gas Recirculation Sensor “A” Circuit High
o P0407 Exhaust Gas Recirculation Sensor “B” Circuit Low
o P0408 Exhaust Gas Recirculation Sensor “B” Circuit High
o P0409 Exhaust Gas Recirculation Sensor “A” Circuit
o P042E Exhaust Gas Recirculation “A” Control Stuck Open
o P042F Exhaust Gas Recirculation “A” Control Stuck Closed
o P044A Exhaust Gas Recirculation Sensor “C” Circuit
o P044B Exhaust Gas Recirculation Sensor “C” Circuit Range/Performance
o P044C Exhaust Gas Recirculation Sensor “C” Circuit Low
o P044D Exhaust Gas Recirculation Sensor “C” Circuit High
o P044E Exhaust Gas Recirculation Sensor “C” Circuit Intermittent/Erratic
o P045A Exhaust Gas Recirculation “B” Control Circuit
o P045B Exhaust Gas Recirculation “B” Control Circuit Range/Performance
o P045C Exhaust Gas Recirculation “B” Control Circuit Low
o P045D Exhaust Gas Recirculation “B” Control Circuit High
o P045E Exhaust Gas Recirculation “B” Control Stuck Open
o P045F Exhaust Gas Recirculation “B” Control Stuck Closed
o P046C Exhaust Gas Recirculation Sensor “A” Circuit Range/Performance
o P046D Exhaust Gas Recirculation Sensor “A” Circuit Intermittent/Erratic
o P046E Exhaust Gas Recirculation Sensor “B” Circuit Range/Performance
o P046F Exhaust Gas Recirculation Sensor “B” Circuit Intermittent/Erratic
o P0486 Exhaust Gas Recirculation Sensor “B” Circuit
o P0487 Exhaust Gas Recirculation Throttle Control Circuit “A” /Open
o P0488 Exhaust Gas Recirculation Throttle Control Circuit “A”
o P0489 Exhaust Gas Recirculation “A” Control Circuit Low
o P0490 Exhaust Gas Recirculation “A” Control Circuit High
o P049A Exhaust Gas Recirculation “B” Flow
o P049B Exhaust Gas Recirculation “B” Flow Insufficient Detected
o P049C Exhaust Gas Recirculation “B” Flow Excessive Detected
o P049D Exhaust Gas Recirculation “A” Control Position Exceeded Learning
o P049E Exhaust Gas Recirculation “B” Control Position Exceeded Learning
o P213A Exhaust Gas Recirculation Throttle Control Circuit “B” /Open
o P213B Exhaust Gas Recirculation Throttle Control Circuit “B”
o P213C Exhaust Gas Recirculation Throttle Control Circuit “B” Low
o P213D Exhaust Gas Recirculation Throttle Control Circuit “B” High
o P2141 Exhaust Gas Recirculation Throttle Control Circuit “A” Low
o P2142 Exhaust Gas Recirculation Throttle Control Circuit “A” High
o P2143 Exhaust Gas Recirculation Vent Control Circuit/Open
o P2144 Exhaust Gas Recirculation Vent Control Circuit Low
o P2145 Exhaust Gas Recirculation Vent Control Circuit High
o P2413 Exhaust Gas Recirculation System Performance

Exhaust Gas Recirculation Valve Pressure Sensors (EVPS or Delta Pressure Feedback Sensor/DPS or DPF)

The Exhaust Gas Recirculation Valve Pressure Sensor monitors exhaust system pressure by sending varying voltages to the onboard computer. The computer then uses this, and information from other sensors, to determine the correct amount of exhaust gas to properly control emissions.

Common causes of Exhaust Gas Recirculation Valve Pressure Sensor failure:
• Clogged EGR valve
• Wiring issues due to temperature
• Vacuum hose issues
• Debris

Symptoms of a failing Exhaust Gas Recirculation Valve Pressure Sensor may include:
• Rough idle
• Engine detonation
• Surging
• Check Engine Light on

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