Bosch ECU Pin Question

[Melspace02]

I have an 86 Carrera and was wondering if anyone could confirm how many pins are in my ecu for a Wong chip. Do all 84-89 have the same ECU narrow body cars?

ECU:

Bosch 0 261 200 050
911.618.111.05

Thanks in advance

[Melspace02]

Anyone?

Thank you

[steve911T]

Many threads. 24 84-86. 28 87-89. Confirm with Mr. Wong. Stev

[al lkosmal]

Here is some info I found.

1984 - '86 0 261 200 050 - uP PN B57312 4006, Date Code 8416, 24 pin EPROM

1988 - '89 0 261 200 082 - uP PN B57312 4006, Date Code 8808, 28 pin EPROM

Although not specifically listed in the info above.....my understanding is that the transition from 24 pin to 28 pin occurred in the 1987 cars....so some 87s are 24 pin and some are 28 pin


regards,
al

[McLaren-TAG]

Then again depending on the car's history the ECU may not be original. It takes a few minutes to check or just send the unit in to Steve if you're not comfortable opening it and want it done right the first time.

[Melspace02]

Thank you everyone. I’ll remove the seat this weekend and open it up

[Lyle O]

Just FYI, you really don't have to remove the seat to get the DME (ECU) out. If you move the seat all the way back, there is enough room (working from the front) to remove the mounting nuts, unlatch the connector, and remove the DME.

[ischmitz]

There are essentially two major hardware revisions of the 3.2 DME. The US versions come with the O2 sensor electronics populated and the early Euro versions have this part not populated. This section is responsible for reading the O2 sensor and adapting the mixture during part-throttle operation. While it is possible to retro-fit this section it really isn't practical.

Then there are 24-pin and 28-pin versions out there. As others said the transition was somewhere around 86 or 87. It is very easy to retrofit the later 28pin sockets to an earlier DME. Some just add the missing pins but the correct way of doing it is to remove the old socket and install a quality 28pin socket. I would always recommend doing that. Here is the rational behind this.

The program in the earlier DME is contained partially in the CPU (lower 4k) and partially in the EPROM (1K or 2K). As EPROM sizes increased the program size and complexity also increased. With the larger available space there were improvements made in how to handle various aspects of engine running. So changing from a stock 24-pin EPROM to a stock 28pin EPROM is already an upgrade.

An aftermarket chip typically uses the base program (either early version in 24pin EPROM or later version in 28-pin EPROM) and then comes with modified part throttle and full throttle fuel and timing maps. Some have modified some other parameters as well. However, the basic code is not touched. Consequently, a 24pin aftermarket chip is not as good as its 28pin counterpart.

Ingo

[Melspace02]

Originally Posted by ischmitz

There are essentially two major hardware revisions of the 3.2 DME. The US versions come with the O2 sensor electronics populated and the early Euro versions have this part not populated. This section is responsible for reading the O2 sensor and adapting the mixture during part-throttle operation. While it is possible to retro-fit this section it really isn't practical.

Then there are 24-pin and 28-pin versions out there. As others said the transition was somewhere around 86 or 87. It is very easy to retrofit the later 28pin sockets to an earlier DME. Some just add the missing pins but the correct way of doing it is to remove the old socket and install a quality 28pin socket. I would always recommend doing that. Here is the rational behind this.

The program in the earlier DME is contained partially in the CPU (lower 4k) and partially in the EPROM (1K or 2K). As EPROM sizes increased the program size and complexity also increased. With the larger available space there were improvements made in how to handle various aspects of engine running. So changing from a stock 24-pin EPROM to a stock 28pin EPROM is already an upgrade.

An aftermarket chip typically uses the base program (either early version in 24pin EPROM or later version in 28-pin EPROM) and then comes with modified part throttle and full throttle fuel and timing maps. Some have modified some other parameters as well. However, the basic code is not touched. Consequently, a 24pin aftermarket chip is not as good as its 28pin counterpart.

Ingo

Awesome info thank you. I spoke with Steve today and I will be sending him my DME to retrofit a later 28pin socket with his chip. Turn around time is quick he said. He said the DME will run cooler as well. Can you feel the difference between the 24pin and 28pin?