P0402 on Volkswagen: How to Diagnose & Fix
Exhaust Gas Recirculation Flow Excessive
3 Volkswagen models · 4 documented issues · 1 critical · $200-$1,500 repair
P0402 on Volkswagen by model: symptoms, diagnosis and fix
The EA189-family TDI diesels (1.6 and 2.0 TDI) suffer frequent EGR valve failures from carbon/soot build-up that jams the valve. The problem became markedly worse after the Dieselgate emissions software fix, which makes the EGR system work harder and has been widely linked to premature EGR failures. Owners report the valve jamming and the engine going into limp mode, with several quoted around £1,400-£1,500 for replacement. Volkswagen has, in many cases, refunded owners for EGR failures occurring after the emissions update.
Common Symptoms
- Engine management / check engine light on
- Loss of power and limp mode
- Rough idle and hesitation
- Increased exhaust smoke
- Higher fuel consumption
How to Fix
Clean or replace the EGR valve (and EGR cooler if clogged). Where failure followed the emissions fix, owners should pursue VW/the supplying dealer for a free-of-charge repair or refund, as VW has refunded many such claims. Regular longer-run driving and a quality EGR-cleaning service slow re-fouling.
Sources for this issue (2)
The 2.0 TDI's diesel particulate filter blocks up on cars used mainly for short, low-speed urban journeys, because the engine never reaches the sustained temperatures needed for passive/active regeneration. A clogged DPF (often combined with a sooty or sticking EGR valve) triggers the exhaust/glow-plug warning lamp, reduced power, limp mode, heavy smoke and more frequent forced regenerations. Reports note this worsened on some cars after the dieselgate NOx emissions software update, which increased regeneration frequency, rough idle and DPF warnings.
Common Symptoms
- Glow-plug/exhaust warning light flashing
- Reduced power / limp mode
- Frequent regenerations / smell of burning
- Black smoke from exhaust
- Higher fuel consumption
- Rough idle after emissions update
How to Fix
Confirm with diagnostics. A partially blocked DPF can sometimes be cleared with a high-speed regeneration run or a forced regen via VAG tooling; a heavily clogged filter needs professional off-car cleaning or replacement, and the EGR valve may need cleaning/replacement. Regular longer/faster drives and correct LongLife diesel oil reduce recurrence. (DPF removal/delete is illegal for road use in the UK/EU and fails the MOT/TÜV.)
Sources for this issue (2)
EU5 Caddy models with the EA189 1.6 TDI and 2.0 TDI engines were subject to the VW emissions ('Dieselgate') recall. After the software/flow-transformer 'fix' was applied (2.0 TDI from 2016, 1.6 TDI from Sept 2016), large numbers of owners reported a wave of EGR valve burn-outs, engine warning lights, and repeated drops into limp mode. The recalibrated emissions strategy makes the EGR work noticeably harder, accelerating its failure. Honest John reports over 60% of affected owners received goodwill EGR replacement payments from VW, indicating VW effectively acknowledged the post-fix failure pattern.
Common Symptoms
- Engine management / glow plug warning light
- Repeated limp mode (reduced power)
- Higher fuel consumption after recall
- Rough running
How to Fix
Have the EGR valve and cooler tested with VCDS/diagnostics; replace the failed EGR valve (and clean the intake) and apply the latest ECU software. Because the failure is linked to the recall, owners should claim a VW goodwill contribution — many received full or partial reimbursement. Regular long runs and good-quality diesel reduce recurrence.
Sources for this issue (3)
Independent of the Dieselgate recall, the Caddy TDI's EGR system clogs with soot/carbon over time. The valve sticks or the low-pressure EGR filter blocks, triggering 'insufficient flow' (P0401) or 'excessive flow' (P0402) codes. The van may otherwise run normally or may drop into limp mode with reduced power. EGR replacement at a VW dealer is costly and a post-repair ECU software update is required.
Common Symptoms
- Limp mode / reduced power
- Engine warning light
- Rough running
- Hesitation under load
How to Fix
Read codes; clean the EGR valve and intake or replace the LP-EGR filter (often an inexpensive fix for P0401). If the valve itself is faulty it must be replaced and the ECU re-flashed. Regular motorway runs and quality fuel slow carbon build-up.
What you need to diagnose it
The repair instructions explicitly call for reading stored codes. Use a scanner that can read the named code families before choosing a repair.The recommended scanner supports these code families; confirm your exact year, model and module coverage before buying.
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Read & clear engine (P) codes
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Reading and clearing the code is DIY work. Module replacement or reprogramming is not — most modules are VIN-programmed, so a new one does nothing until a shop codes it to your car. Check for an open recall or service bulletin before buying anything.
Sources for this issue (3)
P0402 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0402 mean on a Volkswagen?
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 Volkswagen it is documented across 3 models: Touran, Scirocco, Caddy.
What are the most common causes of P0402?
The most common causes of P0402 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0402 on a Volkswagen?
Published repair estimates on Volkswagen range from $200 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0402 on a different make?
View P0402 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.