P03A5 on 2014-2019 Volkswagen Golf R (Golf R Mk7, Golf R Mk7.5) — Cylinder #2 Pressure Variation Too High
1 vehicles · 1 makes · $1,500-$4,200 repair
Most Reported On
P03A5 is an OBD-II diagnostic trouble code meaning “Cylinder #2 Pressure Variation Too High.” P03A5 is set when the engine control module detects that the combustion pressure signal for cylinder #2 is too high or varies beyond the expected range, as reported by that cylinder's in-cylinder pressure sensor (typically integrated into the glow plug on diesel engines that use cylinder-pressure-based combustion control). It is part of the P039C–P03BB block of per-cylinder pressure sensor codes found on engines such as GM/Opel/Vauxhall/Saab 2.0L diesels. It indicates the measured peak combustion pressure for cylinder 2 is out of its normal window, pointing to either a sensor/wiring fault or an actual combustion/mechanical abnormality. This code is most commonly reported on 2014-2019 Volkswagen Golf R (Golf R Mk7, Golf R Mk7.5), with repair costs ranging from $1,500 to $4,200.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P03A5, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
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BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
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LAUNCH CRP123X OBD-II Scanner
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A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
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Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
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- Oil reset, EPB, BMS, TPMS, injector coding
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FAQ
What does P03A5 mean?
P03A5 stands for "Cylinder #2 Pressure Variation Too High." P03A5 is set when the engine control module detects that the combustion pressure signal for cylinder #2 is too high or varies beyond the expected range, as reported by that cylinder's in-cylinder pressure sensor (typically integrated into the glow plug on diesel engines that use cylinder-pressure-based combustion control). It is part of the P039C–P03BB block of per-cylinder pressure sensor codes found on engines such as GM/Opel/Vauxhall/Saab 2.0L diesels. It indicates the measured peak combustion pressure for cylinder 2 is out of its normal window, pointing to either a sensor/wiring fault or an actual combustion/mechanical abnormality.
What are the most common causes of P03A5?
The most common causes of P03A5 are: Faulty cylinder #2 pressure sensor (often combined with the glow plug unit), Wiring or connector problems in the sensor 5V reference, signal, or low-reference circuits, Abnormal combustion in cylinder 2 (faulty/leaking fuel injector causing over-fueling), Mechanical issue raising cylinder pressure (carbon buildup, valve or head gasket problem), Corroded or poor sensor ground/connection, ECM software/calibration or, rarely, ECM internal fault. The specific cause varies by vehicle.
How much does it cost to fix P03A5?
Repair costs for P03A5 range from $1,500 to $4,200, depending on the vehicle and root cause.
Which vehicles are affected by P03A5?
Au7o has documented P03A5 across 1 vehicle models from 1 manufacturers: Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.