ESP Pinout Audi 80 TDI

Hello everyone.

Yesterday, I was planning to install an Audi fuel injection pump (with HDK) into a Golf 3.
Problem: The Audi ESP has a round connector, while the Golf has a rectangular one. So, I soldered together an adapter connector and connected the pin numbers exactly as they should be.
Unfortunately, the Golf wouldn't start. Both ESP units, which are from the 1Z platform, have the same part numbers (except for the last letter). The error codes stored in the system are: fuel temperature sensor and fuel quantity control unit. Based on this, I suspect that the fuel injection pump is incorrectly connected, because it was working perfectly fine in the Audi.
Does anyone happen to know the pinout for a 1Z pump with a round connector?
I would be very grateful.

Best regards, Marcello.

Let me guess: the pump from the Audi is a 028 130 109 J.
"Did you not find it strange that the pump had a different connector and a different part number?"
The last letter belongs to the part number and is extremely important!
The pump with the round connector doesn't have an HDK; it has a potentiometer!
That can't work.

"No, it doesn't have the pot. That was only on the first models that had the return hose on the top of the flow meter (1992-1993). Mine already has the HDK (vent screw located on the side of the flow meter)."

marcello wrote:

Does anyone perhaps know the pinout of a 1Z pump with a round connector??

Hi,

I don't know her, but I would measure the whole thing.
The MSW likely has the lowest resistance, the temperature sensors have the highest, and the RWG (with 3 connections) provides intermediate values.

The polarity of the MSW (motor starter switch) doesn't matter, and the polarity of the sensor is irrelevant in any case.
You may have to try several times with the RWG before it works. However, I don't think anything should break in the process.

How about this:

https://community.dieselschrauber.org/en/viewtopic.php?t=1585&highlight=pinbelegung

Regards,

JRoth

JRoth wrote:

How about it here with

? These are the pin assignments for the oval connector, but this is about the (exotic) round one... if they were the same, Marcello probably wouldn't have a problem .

I realized it later too...


Regards,

JRoth

"Does anyone really have the pinout for a round connector or a circuit diagram?"
Please help me.

Hello Marcello,

Are you absolutely sure that you have an ESP system with an HDK sensor?
I went through my old documents and even the oldest A4 paper I found...
HDK (MJ '95 - i.e., starting around September '94) already has the 'standard' eight-pin connector.
Connector with the following pinout:
1: G149 (HDK) Reference
2: G149 Common
3: G149 Signal
4: G81 (Fuel Temperature) Mass.
5: N146 (Quantity adjuster) Control (mass).
6: N146 Supply +
7: G81 Signal.
8: free.

The old Potigeber positions were filled as follows:
1: G99 (Poti) Grinder (meaning signal).
2: G99 Power Supply.
3: G99 Power Supply (other end of the track resistance).
4: N146 Supply +
5: N146 Control (Mass).
6: G81 Signal.
7: G81 Supply (+?)

Best regards,
Rudi

Hello.
We're talking about the Audi 80 with an HDK engine, because I've never seen an A4 with a 1Z engine. But still, thanks for your effort (I'm still not any further though).

The A4 model was available with a 1Z engine and HDK starting in 1995.

What is the part number of your pump?

Best regards,
Rudi

Apologies for the late reply. The EP has the number 028130109L.

Hi Marcello,

I don't have the pinout, but I do have the following information: The part number 028130109L was replaced by ...115NX, which was used in the 80/90 and Avant models from 1994-1996, and in the Cabrio models from 1992-2000. This corresponds to a Bosch part number: VE4/10E2250R530-1.

All the Bosch ECUs I know of from the early 1Z models with HDK are VE4/10E2250R510-X (with 510 instead of 530). (And later, 590 instead of 510, for example, ALE). This also suggests that yours is not an HDK pump. To my knowledge, the connector is also an indicator of this.

Just unscrew the top cover of the MSW, and you'll see it immediately. Especially for you, as the author of the MSW disassembly guide (thank you for that!), that should be the easiest thing to do.

Regards,
Guste.

guste100 wrote:

Just unscrew the top cover of the MSW, and you'll see it immediately.

. . . or, if you have a multimeter handy, simply measure the resistance between pins 1 and 3: The HDK sensor has only a few ohms (which don't change when voltage is applied to the MSW), while a potentiometer sensor would have a significantly higher resistance due to power loss during operation, estimated to be in the kOhm range.

Warning: Do not apply full battery voltage to the MSW for testing, as this could cause it to spark violently and burn out quickly. Instead, use a turn signal or headlight bulb in series.