# Pin B7 does not appear to work

**URL:** <https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759>\
**Category:** EMU BLACK / CLASSIC\
**Created:** [May 23, 2025, 4:08pm UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759 "2025-05-23T16:08:15Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![BMWE36](https://avatars.discourse-cdn.com/v4/letter/b/e9a140/32.png) [@BMWE36](https://community.ecumaster.com/u/BMWE36)\
**Post date:** [May 23, 2025, 4:08pm UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/1 "2025-05-23T16:08:15Z")

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I’ve got a Classic currently running on my car. I am installing knock sensors and when checking wiring I noticed that pin B2 was already used. I traced the wiring and found it is the signal from the crank sensor. I moved the wire to pin B7 as per wiring diagram and now have no crank signal, if I return wire to pin B2 the crank signal returns and car runs.  
Is there a way of testing pin B7 to check if the ECU is faulty?

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**Author:** ![Greg](https://avatars.discourse-cdn.com/v4/letter/g/71c47a/32.png) [@Greg](https://community.ecumaster.com/u/Greg)\
**Post date:** [May 23, 2025, 4:32pm UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/2 "2025-05-23T16:32:27Z")

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refer to pin numbers on the drawing not what’s is written on the connector

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**Author:** ![BMWE36](https://avatars.discourse-cdn.com/v4/letter/b/e9a140/32.png) [@BMWE36](https://community.ecumaster.com/u/BMWE36)\
**Post date:** [May 23, 2025, 4:59pm UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/3 "2025-05-23T16:59:21Z")

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yes, on the drawing. I checked to make sure I had reference correct against the known earth in pin 24 just in case I had wrong orientation.  
To be clear its the black connector pin 7, B7

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**Author:** ![FloorItGarage](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/flooritgarage/32/61_2.png) [@FloorItGarage](https://community.ecumaster.com/u/FloorItGarage)\
**Post date:** [May 24, 2025, 3:48am UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/4 "2025-05-24T03:48:57Z")

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you’re looking at the pinout backwards;

 ![1](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/a/a507b4c0882be984a79a6ddeef86703a7e8d383d.jpeg)  
this is shown from the ‘wire side’ so looking into the connector of the ECU, not at the terminal side of the connector when it’s disconnected.

Both pin 24 and 17 should be grounded.

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<div class="post-metadata">

**Author:** ![BMWE36](https://avatars.discourse-cdn.com/v4/letter/b/e9a140/32.png) [@BMWE36](https://community.ecumaster.com/u/BMWE36)\
**Post date:** [May 24, 2025, 9:08am UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/5 "2025-05-24T09:08:42Z")

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Thank you, I need to be more observant !

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**Author:** ![FloorItGarage](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/flooritgarage/32/61_2.png) [@FloorItGarage](https://community.ecumaster.com/u/FloorItGarage)\
**Post date:** [May 25, 2025, 4:57am UTC](https://community.ecumaster.com/t/pin-b7-does-not-appear-to-work/3759/6 "2025-05-25T04:57:53Z")

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No worries, did that too when I was starting out.  
Fairly common mistake to make