ECU Guides

EDC15P+ and EDC15VM+ immo off, EGR and stage 1 files for VW Polo, Passat, Golf IV and T4 TDI

7 October 2026 3 min read

Two Bosch boxes, same generation, easy to confuse from a photo. The label on a Passat B5.5 1.9 TDI reads 038906019DS with 0281010543 next to it: that’s EDC15P+, the pumpe-duse controller. A T4 2.5 TDI or an LT35 shows 074906018 and 0281010462 or 0281010407: EDC15VM+, for the rotary-pump engines. Different injection hardware, different file size, different stage 1 approach, and both still turn up in Turkish and Eastern European workshops every week.

Which one is on the car

  • EDC15P+: 1.9 TDI PD (ATD, AXR, AVF, AWX, AJM) in Polo 9N, Ibiza 6L, Golf IV, Passat B5.5 and A4 B6, plus the 1.4 TDI three-cylinder (AMF, BNM) with 045906019 numbers. Flash is 1 MB on most versions.
  • EDC15VM+: VE-pump 1.9 TDI (AHF, ALH, ASV, AGR) in Golf IV, Bora, Octavia I and Caddy, the 2.5 TDI R5 in Transporter T4 and LT (074906018), and the 2.5 V6 TDI in A4 B6 and A6 C5 (8E0907401 numbers, listed as EDC15VM). Flash is 512 kB.

From our shelves

  • VW POLO EDC15P+ 0281010503 045906019AB 1210 1037354620 original
  • SEAT IBIZA EDC15P+ 0281011244 045906019BG 5180 1037368177 original
  • VW POLO EDC15P+ 0281011241 045906019BF 5179 1037368175 EGR OFF
  • VW PASSAT EDC15P+ 0281010543 038906019DS 1348 1037360705 original
  • VW PASSAT EDC15P+ 0281010941 038906019GQ 1582 1037366929 EGR OFF STAGE1
  • VW TRANSPORTER EDC15VM+ 0281010462 074906018AK 3905 1037362446 STAGE1
  • VW TRANSPORTER EDC15VM+ 0281010459 074906018 AL IMMO OFF
  • VW LT35 EDC15VM+ 0281010407 074906018BK 7001 1037371961 original
  • VW GOLF EDC15VM+ 038906012 L 0281010112 IMMO OFF
  • AUDI A6 EDC15VM 0281011387 8E0907401J 0006 1037368568 EGR OFF STAGE1

Questions we get about these two

Can I do immo off over OBD?

Yes, on most versions. EDC15 keeps the immobiliser flag inside the flash rather than in a separate EEPROM, so a Galletto 1260, MPPS or KESS V2 OBD read gives us what we need and you write the modified flash back the same way. Keep the ignition steady, use a battery support unit, and don’t let the laptop sleep mid-write. On a few late EDC15P+ units the OBD session refuses; then it’s the flash chip on the bench with KTAG or a programmer.

Why does the car start but the dash still shows the immo light?

Because immo off tells the ECU to ignore the cluster; it doesn’t tell the cluster the ECU is happy. The key symbol may stay on or flash, depending on cluster software. The engine runs normally. If the customer wants a clean dash, the correct fix is adapting the ECU to the cluster with VCDS using the SKC, which needs the login code from the dealer or a tool like AVDI or VCP that can read it from the cluster.

What does stage 1 do on a VE pump versus PD?

On EDC15VM+ the gain comes from injection quantity and duration, boost and a bit of timing; a 110 hp ALH goes to about 140. Torque limiters matter more than peak power on a T4, because the gearbox and clutch are the weak point. On EDC15P+ the unit injectors give more headroom: a 130 hp AWX lands near 165 to 170 with turbo and clutch stock, and more than that means hardware. The EGR-off request usually rides along because the intake is already blocked with soot by 200,000 km.

Are EDC15P+ and VM+ files interchangeable?

No. Different flash size, different injection model, different pinout. Match the 0281 number and the VAG number, then the software ID (the 1037xxxxxx string).

Before writing anything

Save the original read twice, once on the laptop and once somewhere that isn’t the laptop. EDC15 is old enough that a corrupted write with no backup means a scrapyard search. If the car was towed in as a non-starter, check the crank sensor and the fuel supply before blaming the immobiliser; a P0322 or an air-locked tandem pump has been misdiagnosed as an immo fault plenty of times. And if the reading tool gives you a file that’s the wrong size for the unit (512 kB from a P+, 1 MB from a VM+), stop and check the protocol you selected before you write anything.

Our EDC15P+ and EDC15VM+ pages list stock reads by part number, and the EGR off category holds the modified versions. For immo off, send the full flash read plus a photo of the label via the request form and we’ll return the matched file, usually the same day.

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