The A5 B10 replaces both the previous A4 and A5, moving to the new PPC (Premium Platform Combustion) architecture with CARIAD E3 1.2 software. The 40 TDI pairs the well-proven EA288 evo four-cylinder diesel with a second-generation 48V mild hybrid system (MHEV plus) and 7-speed DL382+ S-tronic. Efficient and refined on the motorway, but the first-year software teething problems and new-generation hybrid system introduce uncertainty that the older B9 generation never had.· more· less
Proven EA288 evo diesel engineAdvanced MHEV plus boosts efficiency
First-gen PPC software teething issues48V MHEV system long-term unproven
Buy if: You want a refined diesel executive car for regular motorway use and are comfortable being an early adopter of new platform technology.
Avoid if: You mainly drive short urban trips (DPF clogging risk) or want a fully mature platform without software teething problems.
First-generation PPC platform software causes dashboard warnings, ADAS failures, and infotainment freezes · more· less
The A5 B10 is among the first vehicles on Audi's new PPC platform with CARIAD E3 1.2 software. Early owners report multiple software-related issues: random dashboard warning lights combined with steering vibration (resolves with power-cycle), driver assistance systems becoming inoperative during mild weather conditions, infotainment screen freezing, and aggressive phantom braking from the emergency braking system. One owner on Audi Owners Club UK reported their 2025 A5 TDI Avant showed faults 4 times in 19 days, with the dealer acknowledging it affects a small number of vehicles while Audi develops a fix. A multi-module software update (TSB 2079690, known as the KD2 update) flashes approximately 30 control modules and addresses many of these problems. The financial cost is typically zero under warranty, but out-of-warranty diagnostic charges of €150-500 per visit could accumulate on older examples.
48V MHEV plus starter-generator failure
€2,000 - 3,5002 of 6
New-generation powertrain starter-generator may fail, causing electrical system shutdown · more· less
The B10 uses a second-generation MHEV plus system with the powertrain starter-generator (PSG) integrated on the transmission output shaft, unlike the belt-driven system in earlier 48V Audis. The older 48V BSG in A6/A7/A8 models has well-documented failures causing complete electrical shutdown while driving, with some owners reporting loss of steering, brakes, and all electrical systems. Audi extended warranty coverage on the older BSG system for 7 years (via service campaign 27BQ), suggesting awareness of the design weakness. Replacement of the 48V starter-generator costs €2,000-3,500 including labor. The MHEV plus design is different (output-shaft mounted vs belt-driven), which may improve or worsen reliability. Insufficient field data exists to determine failure rates. Symptoms of impending failure include intermittent start-stop malfunction and 48V battery charging warnings.
DPF clogging from short-trip driving
€200 - 2,5003 of 6
Diesel particulate filter cannot regenerate properly during predominantly urban driving · more· less
Despite improvements in the EA288 evo, the DPF still requires sustained exhaust temperatures (350-600 degrees Celsius) for regeneration. The MHEV plus system may slightly exacerbate this because electric coasting cools the exhaust system during motorway driving. Active regeneration occurs every 750-1,000 km or when soot loading exceeds 45%. Cars driven primarily on trips under 15 km accumulate soot faster than the system can burn off. A forced regeneration at a workshop costs €150-400. Professional chemical cleaning runs €400-800. Full DPF replacement costs €1,500-2,500. Use a diagnostic tool (OBDeleven or VCDS) to check the DPF soot loading percentage before purchase. Regular motorway runs of 30+ minutes at moderate RPM prevent this issue entirely.
AdBlue system malfunction (SCR dosing, NOx sensor)
€300 - 1,8004 of 6
AdBlue injector crystallization or NOx sensor failure triggers no-restart countdown · more· less
The EA288 evo uses selective catalytic reduction with AdBlue injection to meet Euro 6d emissions standards. The AdBlue injector is prone to urea crystallization at the tip from thermal shock, particularly on vehicles with low annual mileage or predominantly city driving. This was identified in 2023 field data (service bulletin WSC-2022-08) and an updated injector with revised ECU calibration is available. A failed NOx sensor costs €350-700 to replace. The dosing module runs €500-900. The complete SCR system replacement reaches €1,200-1,800. The system triggers a countdown warning when it detects a malfunction, eventually preventing engine restart. The EA288 evo hardware is improved over earlier EA288 variants, but the issue persists for low-mileage city-driven vehicles.
DL382+ S-tronic mechatronic unit wear
€1,500 - 4,0005 of 6
7-speed dual-clutch transmission control unit develops faults at higher mileages · more· less
The DL382+ is a wet-clutch 7-speed dual-clutch unit designed for longitudinal engines handling up to 500 Nm. It is significantly more reliable than the older dry-clutch DQ200, but the mechatronic unit can develop speed sensor failures (P0718), clutch slip under load (P0811), and parking lock malfunctions (P179F) at higher mileages, typically 80,000-120,000 km and beyond. Symptoms include jerky low-speed shifts, delayed engagement from standstill, and gearbox malfunction warnings on the dashboard. Mechatronic repair at a specialist runs €1,500-2,500; full unit replacement at Audi costs €3,000-4,000. Despite Audi's 'lifetime fill' claim, the transmission benefits from fluid changes every 60,000-80,000 km. Given the B10's youth, this is unlikely to affect first owners but relevant for used buyers at higher mileages.
EGR cooler micro-cracks (low-pressure circuit)
€800 - 1,6006 of 6
Aluminium EGR cooler develops thermal fatigue cracks under sustained high loads · more· less
The EA288 evo uses a low-pressure EGR circuit with an aluminium cooler that can develop micro-cracks from thermal cycling, primarily affecting vehicles used for towing or sustained high-speed driving. Symptoms include gradual coolant loss without visible external leaks, white exhaust vapour, and elevated DPF soot accumulation from coolant contamination. Replacement of the EGR cooler assembly costs €800-1,600 depending on whether the DPF and intake require decontamination. This typically appears after 80,000+ km of high-load use. Most standard-use cars will never experience this issue.
Proven engine on an unproven platform
The EA288 evo diesel is a well-established, fundamentally reliable engine that regularly exceeds 200,000 km without major issues. However, the B10 is built on Audi's brand-new PPC platform with first-generation CARIAD software and a redesigned MHEV plus hybrid system. Early ownership reports show software teething problems being addressed through dealer updates. The diesel-specific emissions components (DPF, AdBlue, EGR) carry the same usage-dependent risks as any modern diesel. Long-term reliability data is unavailable given the model's youth. Buyers should expect software updates in the first 1-2 years and monitor the 48V system for early warning signs.
Service history
Complete Audi dealer or authorized specialist records essential. Verify all software updates have been applied.
Tires
Check tread depth, age (date codes on sidewall), and uneven wear patterns. Standard size is 245/40R18.
Cold start
Start engine completely cold. Listen for unusual mechanical noises in the first 30 seconds. Watch dashboard for warning messages.
Test drive
Minimum 30 minutes including motorway, city, and parking situations. Monitor dashboard for any warnings.
Specific for this vehicle
Verify latest software bundle is installed
Ask the dealer which software version is installed and whether the KD2 multi-module update has been applied. Early B10 cars may still run pre-update software with known ADAS and infotainment issues.
Monitor dashboard for warnings during extended test drive
Drive for at least 20 minutes in varied conditions including parking, city, and motorway. Watch specifically for steering, ADAS, or system fault warnings. If any appear, power-cycle the vehicle and retest.
Check DPF soot loading via diagnostic tool
Use OBDeleven or VCDS to read DPF soot level percentage. Below 30% is healthy. Above 50% indicates regeneration problems or predominantly short-trip use.
+ 4 more checksShow less
Verify AdBlue system status and fault history
Check for stored AdBlue-related fault codes. Verify no countdown warning has been triggered. Cars with low annual mileage or purely urban use are higher risk.
Test S-tronic behaviour at low speeds
Drive slowly in stop-start traffic for 10+ minutes. Feel for jerky 1st-to-2nd shifts, delayed engagement from standstill, or hesitation during parking manoeuvres.
Verify 48V MHEV plus system operation
Confirm start-stop functions smoothly and electric coasting engages on the motorway. Watch for any 48V battery warnings or abnormal restart behaviour on the virtual cockpit.
Confirm all recalls are completed
Contact Audi with the VIN to verify seat belt torsion bar recall and any open service campaigns have been addressed.
Recalls and Technical Service Bulletins
Front seat belt torsion bar damage during production (2025)Verify completed
Rear seat belt automatic locking retractor (ALR) defect (2025)Verify completed
Multi-module software update for ADAS and control systems (TSB 2079690, 2025)Verify completed
Contact Audi with the VIN to verify all recalls and software campaigns have been completed. The seat belt recalls affect crash safety and must be confirmed resolved before purchase.
Warranty Status
Factory warranty (2 years)Active on most B10 examples as of early 2026
Rust perforation warranty (12 years)Active on all B10 cars
Extended warranty availabilityAudi Freeway packages available before factory warranty expires
Most B10 A5 40 TDI models are still within their original 2-year factory warranty as of early 2026. Consider purchasing an Audi-backed extended warranty before the original expires, particularly to cover the 48V MHEV plus system and DL382+ transmission. The 48V starter-generator in older Audi models received a 7-year extended warranty via service campaign; similar coverage may become available for MHEV plus.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
