Marelli Weber IAW04E

Lancia Delta Integrale ECM

Project updated 26.12.2003



My friend bought old Lancia Delta Integrale Ralley car. Unfortunately car suffered some running problems. I promised to help him but did not find any information about Marelli Weber IAW04E ECM running the engine. Had to start from scratch. As I am writing this only part of the work is done and things have only tested with ECM on the desk.



I set target for myself to make tester or test environment to be able to read ECM diagnostic data. Most of this is currently working.

ECM can send fault codes by flashing check engine light. This mode is entered sending break or shorting RX data.

ECM can send diagnostic information upon request. More about this in software comments.

ECM can perform some actuator tests. More about this in software comments.

ECM operates with 7812,5 baud speed. I decided to make baud rate converter board with LCD display. Later my intention is to use this same board for in car display.



Label says: Weber IAW 04E Marelli Autronica WH4E.03/085_F6. I nor the current owner of the car knows if this is original ECM for the car. Core of this ECM is Motorola 6803U4 microprocessor. U4-version contains extra timers.

Picture of ECM


Binary file

I have partially disassembled binary file from this particular ECM. My only goal was to find out diagnostic commands and responses. I have completed about 80% of this work. Disassembly is done with DHC11 disassembler.

Disassembly file with some comments.


Baud rate converter

LED D8 on the converter board acts as check engine lamp. Jumper J4 can be used to initiate flash lamp communications.


Firmware for converter board

Pictures. Converter top Converter bottom.



Test Display

Test display and console is Visual Basic software running in PC. Current version is only for test commands and responses. There are still some undecoded fields in communication protocol. This test code is done with VB6.

Visual Basic test software


If you know anything more about this ECM I am pleased to hear.