P0402 on Jaguar
Exhaust Gas Recirculation Flow Excessive
P0402 on Jaguar vehicles indicates exhaust gas recirculation flow excessive. Au7o has documented this code across 1 Jaguar model — most commonly on XJ. P0402 means the Exhaust Gas Recirculation (EGR) system is flowing too much exhaust back into the intake. The EGR system intentionally routes a small amount of inert exhaust gas into the engine to lower combustion temperatures and reduce nitrogen-oxide emissions, but the flow must be metered precisely. When the PCM determines the flow is excessive — often because the EGR valve is stuck open or letting gas through when it shouldn't — it sets this code. Too much EGR can cause rough idle, stalling, hesitation, and a check engine light. Typical repair costs on Jaguar range from $400 to $3,000, depending on the specific model and root cause.
Common Causes of P0402
- •EGR valve stuck open or not closing fully
- •Failed or sticking EGR valve diaphragm/solenoid
- •Carbon buildup holding the EGR valve open
- •Faulty EGR position or differential pressure (DPFE) sensor
- •Leaking EGR valve gasket or pintle seat
- •Vacuum control or solenoid fault commanding EGR open
- •Wiring or connector problems in the EGR control circuit
P0402 on Jaguar by Model
Jaguar XJ(1 issue)
- 2.7 TDV6 EGR Valve Sticking and Inlet Y-Piece Carbon Blockage Causing Restricted Performance and Turbo Bearing Failure2005-2009
On the 2005-2009 X350 XJ 2.7 diesel the twin EGR valves and the plastic inlet 'Y-piece' clog with soot. A valve stuck open feeds carbon back into the intake, restricts airflow and triggers 'Restricted Performance' limp mode; a valve stuck or leaking oil has been linked by owners and specialists to turbocharger bearing failure, and a replacement turbo will fail again if the EGR is not fixed at the same time. Threads on the XJ, XF and Discovery 3/Range Rover Sport (same engine) all document the same pattern.
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View P0402 across all makes →Frequently Asked Questions
What does P0402 mean on Jaguar?▼
P0402 stands for "Exhaust Gas Recirculation Flow Excessive." P0402 means the Exhaust Gas Recirculation (EGR) system is flowing too much exhaust back into the intake. The EGR system intentionally routes a small amount of inert exhaust gas into the engine to lower combustion temperatures and reduce nitrogen-oxide emissions, but the flow must be metered precisely. When the PCM determines the flow is excessive — often because the EGR valve is stuck open or letting gas through when it shouldn't — it sets this code. Too much EGR can cause rough idle, stalling, hesitation, and a check engine light. On Jaguar specifically, this code is documented across 1 model.
What causes P0402 on Jaguar vehicles?▼
Common causes on Jaguar: EGR valve stuck open or not closing fully, Failed or sticking EGR valve diaphragm/solenoid, Carbon buildup holding the EGR valve open, Faulty EGR position or differential pressure (DPFE) sensor, Leaking EGR valve gasket or pintle seat. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0402 on a Jaguar?▼
Repair costs on Jaguar range from $400 to $3,000, depending on the specific model and root cause.
Which Jaguar models have P0402 documented?▼
Au7o has documented P0402 on 1 Jaguar model: XJ.