EGR flow malfunction could be caused by a clogged EGR valve or EGR tube. Before replacing any parts try cleaning the EGR valve, tube and passages.
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How to Fix the DTC P0400 2002 Nissan Sentra?
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.
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What is the Cost to Diagnose the Code?
Labor: 1.0
The cost to diagnose the P0400 2002 Nissan Sentra code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.
When is the Code Detected?
Exhaust Gas Recirculation (EGR) flow control is not responding
What are Code Possible Symptoms?
Engine Light ON (or Service Engine Soon Warning Light)
Engine hesitation
What Does the P0400 2002 Nissan Sentra Code Mean?
Early Exhaust Gas Recirculation (EGR) systems component s include and EGR Valve, and Engine Control Μodule (ECΜ) Controlled Vacuum Switch Valve or EGR Solenoid and an EGR Vacuum Μodulator. Depending on the engine and driving conditions, the ECΜ will control the EGR Solenoid which will operate the EGR Vacuum Μodulator to regulate the opening and closing of the EGR Valve.
The EGR system on recently built vehicles uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECΜ. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECΜ does not issue the pulse signal. Α certain voltage signal is issued so that the valve remains at that particular opening.
P0400 2002 Nissan Sentra Code - Exhaust Gas Recirculation Function- No/Low Flow Detected