# E34 M50b25tu emu classic + pnp adaptor

**URL:** <https://community.ecumaster.com/t/e34-m50b25tu-emu-classic-pnp-adaptor/6420>\
**Category:** EMU BLACK / CLASSIC\
**Created:** [August 31, 2026, 2:13pm UTC](https://community.ecumaster.com/t/e34-m50b25tu-emu-classic-pnp-adaptor/6420 "2026-08-31T14:13:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![M50wut](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@M50wut](https://community.ecumaster.com/u/M50wut)\
**Post date:** [August 31, 2026, 2:13pm UTC](https://community.ecumaster.com/t/e34-m50b25tu-emu-classic-pnp-adaptor/6420/1 "2026-08-31T14:13:14Z")

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Trying to set my emu classic up

Not getting anywhere really

Fuel pump doesn’t prime. Test shows no voltage change, stays at 12v

I’ve confirmed all the pins are correct

To my knowledge the adaptor comes from the OEM harness and all the pins are 1:1 /A1 to A1 and so on

I have triple checked this with continuity

Car starts fine with OEM ECU

Here is what I’ve back proved and tested

Tps shows a consistent change but only from 2.3v to 2.6 at a push

Using body earth

Tps brown wire shows 5v

Brown and black shoes the 2.3v to 2.6v change

And red/yellow show 0

- **B23 → B18:** latest = **steady 5 V**
- **B18 → B24:** latest = **5 V**
- **B23 → B24:** latest = **0 V**
- **B12 → B18:** latest = **2.3 V closed → 2.45 V WOT**
- **B18 → body:** latest relevant result = **0.04 V**
- **B24 → body:**  **0 V**
- **Main power → ground:**  **12 V**
- **TPS 5 V → TPS ground:**  **5 V**
- **TPS itself:**  **1.4 → 4.8 Ω smoothly**
- **OEM sensor ground → adapter sensor ground:**  **0.5–1 Ω**
- **OEM sensor ground → body:**  **14 Ω**
- **AUX 5:**  **12.77 → 12.72 V during test**
- **TPS software:**  **~0.2 V, doesn’t move**

Thanks for any help

I’m losing sanity here

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<div class="post-metadata">

**Author:** ![M50wut](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@M50wut](https://community.ecumaster.com/u/M50wut)\
**Post date:** [September 1, 2026, 7:43pm UTC](https://community.ecumaster.com/t/e34-m50b25tu-emu-classic-pnp-adaptor/6420/2 "2026-09-01T19:43:49Z")

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All sensors using the sensor ground don’t work  
I think the emu classic has an issue internally but idk how to confirm this

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<div class="post-metadata">

**Author:** ![M50wut](https://avatars.discourse-cdn.com/v4/letter/m/34f0e0/32.png) [@M50wut](https://community.ecumaster.com/u/M50wut)\
**Post date:** [September 4, 2026, 1:52pm UTC](https://community.ecumaster.com/t/e34-m50b25tu-emu-classic-pnp-adaptor/6420/3 "2026-09-04T13:52:49Z")

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Figured out the wiring is meant to be backwards to the pins on the ECU  
A1on the connector actually goes to A8 on the ECU  
According to the laminated diagram that comes with the ECU  
I’ve got everything working  
Car runs but I’m diagnosing my tps reading now  
I’m getting an alternating voltage from the 5v supply to the sensor ground on the tps plug  
Of around 1.7v to 4.9v  
It flickers between both maybe once or twice a second

Coolant temp does the same from 1.7v to 3.5v  
Sensor ground to 5v supply on the ECU actual pins gives a steady 5v so ECU is fine  
Everything on the software reads steady consistent results other than tps which gives me very erratic readings when on the throttle  
And sits at closed throttle jumping from 0.22v to 0.55v  
It seems to double depending on base voltage  
1v becomes 2  
2v becomes 4 and so on  
Causing massive spikes in tps reading  
Trying to diagnose