P0403 on Nissan
Exhaust Gas Recirculation Circuit Malfunction
P0403 on Nissan vehicles indicates exhaust gas recirculation circuit malfunction. Au7o has documented this code across 4 Nissan models — most commonly on 370Z, Leaf, Pathfinder. This emissions code indicates a malfunction in the exhaust gas recirculation (EGR) control circuit. The EGR system routes a small amount of exhaust back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer commands the EGR valve open and closed through this circuit. The code sets when the electrical control signal to the EGR valve or its solenoid is out of the expected range — for example, an open, short, or a commanded change that doesn't produce the right feedback. It generally points to an electrical or wiring problem in the EGR control circuit, or the EGR valve/solenoid itself, rather than carbon clogging alone. Typical repair costs on Nissan range from $200 to $8,000, depending on the specific model and root cause.
Common Causes of P0403
- •Faulty EGR valve or EGR solenoid
- •Damaged wiring or connector in the EGR control circuit
- •Open or short in the EGR control wiring
- •Corroded or loose EGR connector
- •Blown fuse or lost power supply to the EGR circuit
- •Carbon buildup binding the EGR valve
- •Faulty engine control module or driver circuit
P0403 on Nissan by Model
Nissan 370Z(1 issue)
- Concentric Slave Cylinder (CSC) Failure2009-2020
The 370Z is notorious for concentric slave cylinder failures, which is integrated with the clutch release bearing inside the transmission bell housing. When it fails, the clutch cannot be disengaged. This requires transmission removal to replace, making it a costly repair.
Nissan Leaf(1 issue)
- Battery Pack Capacity Degradation2011-2023
The Nissan Leaf uses an air-cooled lithium-ion battery that degrades faster than liquid-cooled competitors. Hot climates (Arizona, Texas) accelerate degradation significantly. Early models (2011-2015) with 24 kWh packs can lose 30-40% capacity within 5-7 years. Nissan provides an 8-year/100,000-mile battery warranty covering loss below 9 bars (approximately 66% capacity) on the dashboard gauge.
Nissan Pathfinder(1 issue)
- Coolant Leak from Thermostat Housing (VQ35DE)2013-2020
The 2013-2020 Pathfinder VQ35DE engine develops coolant leaks from the thermostat housing/water outlet, typically around 60,000-100,000 miles. The plastic housing cracks or the O-ring seal degrades, causing a slow coolant leak that can lead to overheating if not addressed. This is a common issue shared with the Murano and Maxima VQ35 engines.
Nissan Sentra(1 issue)
- A/C Compressor Failure2013-2019
The A/C compressor on 2013-2019 Sentra models is known to fail prematurely, often within 60,000-80,000 miles. The compressor clutch bearings seize or the internal components disintegrate, sending metal debris throughout the A/C system. When the compressor fails internally, the entire system often needs flushing.
Looking for P0403 on a different make?
View P0403 across all makes →Frequently Asked Questions
What does P0403 mean on Nissan?▼
P0403 stands for "Exhaust Gas Recirculation Circuit Malfunction." This emissions code indicates a malfunction in the exhaust gas recirculation (EGR) control circuit. The EGR system routes a small amount of exhaust back into the intake to lower combustion temperatures and reduce nitrogen-oxide emissions, and the computer commands the EGR valve open and closed through this circuit. The code sets when the electrical control signal to the EGR valve or its solenoid is out of the expected range — for example, an open, short, or a commanded change that doesn't produce the right feedback. It generally points to an electrical or wiring problem in the EGR control circuit, or the EGR valve/solenoid itself, rather than carbon clogging alone. On Nissan specifically, this code is documented across 4 models.
What causes P0403 on Nissan vehicles?▼
Common causes on Nissan: Faulty EGR valve or EGR solenoid, Damaged wiring or connector in the EGR control circuit, Open or short in the EGR control wiring, Corroded or loose EGR connector, Blown fuse or lost power supply to the EGR circuit. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0403 on a Nissan?▼
Repair costs on Nissan range from $200 to $8,000, depending on the specific model and root cause.
Which Nissan models have P0403 documented?▼
Au7o has documented P0403 on 4 Nissan models: 370Z, Leaf, Pathfinder, Sentra.