I'm trying to test the temperature sensor remotely from the ECU.

I a post indicated it was on terminal #2. I see #2 on the wiring diagram.

Then I get lost.

The pin layout on the wiring diagram is not the same as the physical pin layout and I am not finding any numbers on the case. There two rows and they are not symmetrical and do not have the same number of connection on each side.

How do I know where to start counting from?

The numbers are molded on the plug, but hard (for me) to photograph.

These photos are from the earlier LH with only 25 pins. Yours has 35 pins so the long row ends with 18. You can identify pin 2 on the 89's plug by its yellow/white wire, but I think you are really after the ECT signal, which is on pin 13, a blue/red wire. Could be you are reading about the earlier LH.





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Art Benstein near Baltimore

A man rushed into a busy doctor's office and shouted, "Doctor! I think I'm shrinking!" The doctor calmly responded, "Now, settle down. You'll just have to be a little patient."

I pulled the back off, and looking at the female end:

top

1 14
2 15
3 16
4 17
5 18
6 19

10 22
11 23
12 24
13 25

bottom

and looking at the colored wires the missing numbers are inferred
and the numbers need to be counted disregarding blank slots and the numbering on the back.

CORRECTIONS:
--------
1988 244 DL
--------
Under Passenger Side Dash ECU Pin Numbers.

TOP
---
1 14
2 15
3 16
4 17
5 18
6 19

10 22
11 23
12 24
13 25
---
BOTTOM

Disregard counting wires. Empty slots are non-existent wires.

To test at connector:
Disassemble it, removing long plastic plugs on each side below sockets, and probe sides to avoid damage to female sockets.

Yup, that's a mystery I haven't heard the answer for: why did they omit the numbering on the mold for those specific 5 pins. Not that we need them.
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Art Benstein near Baltimore

Evidence has been found that William Tell and his family were avid bowlers. Unfortunately, all the Swiss league records were destroyed in a fire, ...and so we'll never know for whom the Tells bowled.

Thank you Art.

ECU Pins

Left
I have 12 slots w/ 1 empty

Right
I have 13 slots w/ 1 empty

------------------------

Lambdasond

Is the Oxygen sensor also called Lambdasond?

If so, am I able to check its operation by jacking in to this test connector off the ECU?

OK, I think I understand our mis-communication. I am thinking fuel ECU and you are apparently looking at the ignition ECU, which I'm in the habit of calling an ICU, or you are working on some other car besides a US 1989 240. Either way, the pin numbers are ID'd with the same molded numbers, but you'll have to ignore the wire colors I cited before.

Yes lambdasond = oxygen sensor.
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Art Benstein near Baltimore

Back in the 1800's the Tate's Watch Company of Massachusetts wanted to produce other products, and since they already made the cases for watches, they used them to produce compasses. The new compasses were so bad that people often ended up in Canada or Mexico rather than California . This, of course, is the origin of the expression,..."He who has a Tate's is lost!"