P046C on Opel: How to Diagnose & Fix
Exhaust Gas Recirculation Sensor "A" Circuit Range/Performance
2 Opel models · 2 documented issues · 2 critical · $550-$1,800 repair
P046C on Opel by model: symptoms, diagnosis and fix
The B16DTH "Whisper Diesel" 1.6 CDTI in Zafira Tourer (and shared Astra J/K) suffers EGR cooler failure with similar symptoms to the 2.0 CDTI: coolant disappearing, white smoke, and sweet smell. Typical onset 80,000-150,000 km.
Common Symptoms
- coolant loss
- white smoke
- sweet smell
- sluggish performance
How to Fix
EGR cooler assembly replacement €550-€1,100. Check for coolant in oil (head gasket damage from hydrolock attempts). Use only Dex-Cool-compatible coolant (G12++) — mixed coolants accelerate failure.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Opel 55509027 EGR cooler assembly for Zafira C 1.6 CDTI
Confirm VIN/engine; alternate D16/B16 variants require seller/EPC confirmation.
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The A20DT/A20DTH 2.0 CDTI EGR cooler develops internal cracks, allowing coolant to leak into the intake. Symptoms: white smoke from exhaust, mysterious coolant loss with no external leak, sweet smell, eventual no-start as cylinders flood. Common at 100,000-180,000 km. Same engine in Astra J, Zafira C, Cascada.
Common Symptoms
- white exhaust smoke
- mysterious coolant loss
- sweet smell
- no start
- P-codes
How to Fix
EGR cooler replacement €600-€1,200 incl. labor. If coolant has been pulled into cylinders, hydrolock check required. Some independents recommend EGR delete + remap — illegal in most markets and disqualifies TÜV inspection.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine 55590953/55572962 EGR cooler and valve repair kit
Insignia A 2009-2017 2.0 CDTi engine family listed as A20DT/A20DTC/A20DTE/A20DTH/A20DTJ/A20DTL/A20DTR and related Y/Z20 codes. Confirm VIN and OE 55590953/55572962.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
P046C 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 P046C mean on a Opel?
P046C stands for "Exhaust Gas Recirculation Sensor "A" Circuit Range/Performance." This code means the engine computer found that the signal from the exhaust gas recirculation (EGR) position/flow sensor is out of its expected range or not changing the way it should compared with commands. The EGR system routes a measured amount of exhaust back into the intake to lower combustion temperatures and reduce emissions, and this sensor reports how far the valve is open or how much gas is flowing. An implausible reading suggests the sensor, the valve it monitors, or the wiring is not performing correctly, which can affect emissions and sometimes idle quality. On Opel it is documented across 2 models: Zafira, Insignia.
What are the most common causes of P046C?
The most common causes of P046C are: Faulty EGR position or flow sensor, Carbon buildup clogging the EGR valve or passages, Sticking or failing EGR valve, Damaged, corroded, or loose sensor wiring/connector, Bent or pushed-out connector terminals, Vacuum or exhaust leak affecting EGR flow, PCM fault (rare). The specific cause varies by vehicle.
How much does it cost to fix P046C on a Opel?
Published repair estimates on Opel range from $550 to $1,800 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 P046C on a different make?
View P046C 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.