KESS V2 Pinout & K-TAG Pinout – DB15 Boot Cable Wiring Diagram

Post #1

This article shows the DB15 BOOT cable pinout used with KESS V2 Master and K-TAG / KTAG ECU Master ECU flashers.

In some cases, users may experience no communication with the ECU when connecting in BOOT mode. One of the common reasons is an incorrect DB15 cable pinout or a BOOT cable wired for another device.

KESS V2 and K-TAG DB15 BOOT cable pinout comparison diagram showing connector pin numbers and wire colors


KESS V2 and K-TAG DB15 cables are not interchangeable​#


Although the DB15 cable from K-TAG ECU Master looks identical to the DB15 cable from KESS V2 Master, these cables have different pinouts.

This means that a KESS V2 DB15 BOOT cable is not suitable for K-TAG / KTAG ECU Master, and a K-TAG DB15 BOOT cable is not suitable for KESS V2 Master.

To check your BOOT cable, open the DB15 connector housing and compare the wiring with the pinout diagram. The main differences are related to the brown and green wires, as well as the yellow and purple wires.

KESS V2 vs K-TAG DB15 BOOT cable pinout differences​#


  • Pin 8 — K-TAG: Brown / RESET; KESS V2: Green / CAN-L
  • Pin 7 — K-TAG: Purple / VPP; KESS V2: Yellow / K-Line
  • Pin 9 — K-TAG: Green / CAN-L; KESS V2: Brown / RESET
  • Pin 10 — K-TAG: Yellow / K-Line; KESS V2: Purple / VPP

The main difference between the KESS V2 DB15 BOOT cable pinout and the K-TAG / KTAG DB15 BOOT cable pinout is that the Brown/Green and Yellow/Purple wire pairs are swapped.

DB15 BOOT cable wire color functions​#


  • GREEN — CAN-L
  • ORANGE — VKEY / key switched power +12V
  • YELLOW — K-Line
  • RED — VECU / ECU power +12V
  • BLACK — Ground / GND
  • PURPLE — VPP
  • WHITE — CAN-H
  • BROWN — RESET
  • GRAY — BOOT
  • BLUE — CNF1

Some DB15 BOOT breakout cables may include duplicated power and ground wires, such as two red wires for ECU power, two orange wires for key switched power and two black wires for ground.

KESS V2 and K-TAG 14P600KT02 ECU BOOT cable wiring setup with DB15 pinout, interface box and laptop connection


A correctly wired DB15 BOOT cable is required for stable ECU communication in BOOT mode via K-Line and CAN. Before troubleshooting the ECU, software, drivers or the interface box, always verify that the DB15 cable pinout matches your device: KESS V2 or K-TAG / KTAG.
 
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Post #2

Great reference post. A couple of additional notes that might save someone a headache:

Key pin differences at a glance (from the diagram):

  • Pin 8 (top row) — Brown on K-TAG, Green (CAN-L) on KESS
  • Pin 7 (top row) — Purple on K-TAG, Yellow (K-Line) on KESS
  • Pin 9 (bottom row) — Green on K-TAG, Brown on KESS
  • Pin 10 (bottom row) — Yellow on K-TAG, Purple (VPP) on KESS

Essentially the Brown↔Green and Yellow↔Purple pairs are swapped between the two devices. Everything else (Red, Blue, Black, White, Orange, Grey) stays on the same pins.

Common mistakes to watch for:

  • If you bought a clone or second-hand unit and the DB15 cable came from a different device, you'll get "no communication" or "connection error" in boot mode — the ECU won't enter boot because RESET, BOOT, and VPP are landing on the wrong pins.
  • If you're making a custom cable or rewiring, always verify with a multimeter from the DB15 pin to the breakout wire end — don't trust wire colors alone, especially on clone cables where colors can be inconsistent.
  • The 14P600KT02 breakout cable (shown in the first diagram) is the ECU-side harness and is the same for both tools — it's only the DB15 connector side that differs between KESS V2 and K-TAG.
  • Don't forget the external 12V power supply to the interface box. Boot mode won't work reliably from USB power alone.

Solid diagrams — this should be pinned for anyone troubleshooting boot mode connection issues. 👍
 
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