Table of Contents


This part was taken from a Motronic M1.7.3 engine control unit (ECU), which was commonly used on 1.6L & 1.8L 4-cylinder BMWs of the mid-E36 generation. While this chip was likely used on a number of ECUs, the specific one in this case had Bosch PN 0 261 203 661.

This chip is believed to be a Philips 74HC4066 quad bilateral switch. Functionally, it is used to switch control signals to the Bosch b30098 knock signal processor, as well as switching the b30098's conditioned analog outputs when they need to be supplied to the ECU MCU's ADC inputs.


Label (top):

57803 (Bosch internal PN)
Hnn9604 D
[Philips Logo]


Decap Steps:
(Bic lighter + water quench) x 2 cycles
Selective crushing with pliers and bench vise

Capture Details:
Imaging device: Keyence VHX-2000
Magnification: 1000X

LT 705D

Note: This is a ~4X downsampled version of the original image. A full resolution version (7MB) can be provided. On the to-do list…

felinefriendly/bosch/b57803.txt · Last modified: 2018/07/27 07:11 by e30tuner
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