EDC15P on the 1.9 TDI PD 8v

Bosch EDC15 diesel family for VAG 1.9 TDI 8v — the true tuning target here is EDC15P+ (Pumpe-Duse unit-injector core). Per 'always verify part number', the supplied code list spans THREE ECU generations that are NOT one flash target: (1) EDC15V / EDC15VM+ (VP37 electronic rotary distributor pump, NOT PD): ALH 90hp, AHF 110hp, ASV 110hp — same tuning philosophy (smoke limiter / boost / driver-wish)

Reference - updated 7 October 2026

The ECU hardware

Siemens/Infineon C167-class 16-bit microcontroller (SAK-C167CR/CS). Program + calibration live in an EXTERNAL NOR flash: AMD/Fujitsu Am29F400 or ST M29F400 (marking often 29F400BT), 4 Mbit = 512 KB. C167 is LITTLE-ENDIAN. A separate small on-board serial EEPROM (24C02/24C04 or M95040-class) holds immobiliser + adaptation/learned data, kept OUT of the program flash. EDC15P+ boards drive the PD (unit-injector) solenoids directly; EDC15V boards drive a VP37 pump. Pre-encryption era: NO cryptographic secure-boot and NO signed flash.

Fuelling and load sensing

Diesel — 1.9 TDI 8-valve. EDC15P+ = Pumpe-Duse (one cam-driven unit injector per cylinder, solenoid-timed, peak injection pressures ~1800-2050 bar on stock 1.9 nozzles). EDC15V = VP37 electronic rotary distributor pump (ALH/AHF/ASV). There is NO common rail on this platform, so 'rail pressure' maps do NOT exist and do NOT apply: fuel is metered by injected QUANTITY (mg/stroke) and injector energizing DURATION vs quantity/RPM, with injection TIMING (SOI) set separately. Airmass is measured with a hot-film MAF (LMM), not a MAP+IAT speed-density model (that is EDC16/17).

How this ECU is read and flashed

Read/write over OBD-II on the K-LINE using KWP2000 (ISO 14230). EDC15 diagnostics/flash is K-LINE, NOT CAN (CAN flashing is EDC16+). Tools: MPPS, Galletto 1260, KESS/KTAG, VAG-Tacho / VAG-Commander, KWP2000+, MTX. The full 512 KB is read and written via the ECU bootloader/flash routine over OBD — no bench work needed for a normal VAG EDC15 tune. Security: KWP2000 SecurityAccess (service 0x27) seed/key — the VAG EDC15 seed/key algorithm is known and built into these tools; Bench/boot fallback: C167 BDM or connector bootstrap/BSL for recovery of a bricked unit (rarely needed on VAG EDC15). IMMO: immobiliser + adaptation data live in the on-board serial EEPROM (24C02/24C04 or 95040-class), NOT in program flash, so flashing a tune does NOT touch immo and does NOT require immo authentication (unlike ME7 petrol, where flash is immo-gated). ECU swaps/virginising need a SEPARATE EEPROM read/edit (SKC/immo); tuning does not.

Engine codes in this family

• ATD (PD100, EDC15P+)
• AXR (PD100, EDC15P+)
• AVB (PD101, EDC15P+)
• AVF (PD130, EDC15P+)
• BEW (PD100, EDC15P+)
• ASZ (PD130, EDC15P+ — related)
• ARL (PD150, EDC15P+ — related)
• AJM/ATJ (PD115, EDC15P+ — early PD, related)
• ALH (90hp, EDC15V/VP37 — NOT PD)
• AHF (110hp, EDC15V/VP37 — NOT PD)
• ASV (110hp, EDC15V/VP37 — NOT PD)
• BXE (PD105, EDC16U34 — NOT EDC15, route to EDC16)
• BLS (PD105 DPF, EDC16U34 — NOT EDC15, route to EDC16)
• BJB (PD105, EDC16U34 — NOT EDC15, route to EDC16)

Staging - what each stage really gives

• stage1 - Software-only. Raise the smoke limiter (fuel vs airmass), the boost target AND boost limiter together, the driver-wish, and the torque/max-quantity limiter in LOCKSTEP; minor SOI and duration trim; optional EGR reduction. Keep injector duration/IQ stock on stock nozzles. Typical: PD100 (ATD/AXR/BEW) ~100->130-140hp and ~240->~310-330Nm; PD130 (AVF/ASZ) ~130->~160-165hp and ~310->~370-385Nm; PD150 (ARL) ~150->~180hp; VP37 (ALH/AHF/ASV) similar +25-40%. Net roughly +30-50hp / +60-100Nm. Safe on stock hardware, but PD130+ is already near the stock clutch and bottom-end torque limit.
• stage2 - Bolt-ons + retune. Full 2.5-3in downpipe/de-cat exhaust, larger intake, uprated front-mount intercooler + hard pipes, EGR delete, sometimes a mild hybrid VNT; map re-optimised for the extra airflow. Typical ~150-170hp (PD100 up to ~155-165hp; PD130 ~175-185hp), torque ~370-420Nm. Uprated clutch strongly recommended (effectively mandatory on PD130+), and this is where larger PD nozzles begin to help.
• stage3 - Hardware limit. Hybrid/larger turbo (e.g. GT1749VB, GTB1756VK, GTB2260VK), larger PD nozzles (stock ~0.520 -> 5.5%/10%/DLC oversize; Darkside/PPD/Kerma), uprated clutch (sprung organic or paddle) + often a single-mass flywheel conversion, big FMIC, and UPRATED/FORGED CONNECTING RODS for the top of the range (the stock 1.9 PD rods are the known failure point). Fully custom map re-calibrating smoke/duration/IQ/SOI/boost. Typical ~180-240hp, torque ~420-500Nm. Con-rods/bearings, clutch, DMF and the 02J/02M gearbox become the reliability limits.

Safety limits

• EGT (pre-turbine): keep < ~750C continuous, brief peaks < ~800C; sustained > ~850C melts pistons and cooks the turbine. CRITICAL: EDC15 PD has NO factory EGT sensor — EGT is UNMONITORED by the ECU, so fuel/smoke MUST be set conservatively and, for hard use, verified with an added pyrometer.
• Air margin / smoke: full-load lambda should stay roughly >= 1.10-1.15 for a streetable clean tune. Never fuel past the airmass the smoke limiter has air for — visible black smoke = over-fuelled = soot, EGT and NO real power. Always keep a positive air margin above fuel.
• Boost / VNT overspeed: stock VNT (GT1749V on the 1.9) is safe to ~1.1-1.2 bar gauge (~2.1-2.2 bar absolute). Overboost deviation beyond the ECU window trips limp (P0234 / P1557). Above ~1.3 bar gauge you run off the compressor efficiency island and risk overspeeding/failing the turbo — raise the boost limiter WITH margin, not to the roof, and keep the atmospheric/altitude limiter functional so the VNT is not overspeeded at altitude.
• Injection quantity / duration + PD driveline: do not exceed injector + PD-cam delivery capability. Over-duration on stock nozzles gives incomplete combustion, smoke and EGT with no power, and adds load to the PD camshaft/injector rockers (a known TDI wear item). Larger nozzles require re-scaled duration AND IQ correction.
• Over-advanced SOI spikes PEAK CYLINDER PRESSURE and is a primary rod-killer, so keep peak torque and injection timing sane. Serious power (Stage 3) needs forged/uprated rods (and ARP-grade fasteners).
• Torque / clutch / DMF / gearbox: stock sprung SMF/DMF clutch holds ~250-350Nm; beyond ~320-350Nm it slips, and the dual-mass flywheel is itself a failure point. Stage 2/3 torque needs an uprated clutch; keep the torque limiter aligned so the driveshafts and the 02J (5-spd) / 02M (6-spd) gearbox are not overstressed.
• Thermal headroom: keep coolant/oil temperature margin — sustained high-load diesel tuning without cooling headroom risks the turbo and top end. Note: EDC15 has NO DPF, so no DPF-regen or soot-load limit applies here — that limit belongs to the out-of-scope EDC16 codes (BLS/BXE/BJB) and must NOT be modeled on EDC15.

Every car using this platform (18)

Stock power and typical remap figures per car. Stage results assume a healthy engine on good fuel.

How confident is this?

SOLID: platform/hardware (C167 + external Am29F400/29F400BT, 512KB, little-endian); K-line KWP2000 OBD read/write with 0x27 seed/key and no crypto; immo lives in board EEPROM so tuning flash is NOT immo-gated; the core map set and its lockstep logic (smoke limiter <-> boost target/limit <-> torque/max-quantity limiter <-> driver wish); additive/complement checksums fully correctable by WinOLS/ECM Titanium/Swiftec/OBD flasher; staging gains and the diesel safety envelope; and the 1.9 PD connecting-rod bottom-end limit (well-established community knowledge). MEDIUM: exact map dimensions/dtypes (16x16/u16 typical but vary by software version); precise checksum block boundaries (version-specific); exact stock nozzle sizing/limits. THIN / DO NOT INVENT: exact per-software flash ADDRESSES — must come from a version-matched DAMOS/A2L/XDF plus datalog validation, never hardcoded; exact German DAMOS label spellings for EDC15P diesel vary by revision; and specific VAG-PN->software-suffix mappings (treat 038906019xx examples as illustrative).