2015 Renault Megane DCi - 2015 Megane broken down. Please help.

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Tue 20 Feb 2024 10:00
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - Gordon the golfer

Hi everyone. Please can someone help me.

My normally reliable 2015 Renault Megane 1.5 diesel has broken down and I don't know what it is and need help fixing it.

Out of nowhere, the following warning lights came up on the car display and it went into limp mode.

- Check hill start assist
- Check ESC
- Check injection system
- Check Stop Start

I've fitted a new like for like battery and cleared all previous OBD codes and the current permanent codes are

- DTC020129 Cylinder 1 injector control circuit invalid signal
- DTC926768 Stop start module circuit invalid
- DTC407481 Engine torque multiplexed information status
- DTC038096 pre heating unit diagnostic connection internal component failure

Please can someone advise as I really need my car again.

Thank you in advance


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Tue 20 Feb 2024 10:07
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - RichardW

Might be a wiring fault to Injector No 1, but most likely it needs a new one. The other faults will probably go away once the injector is fixed.

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Tue 20 Feb 2024 10:16
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - elekie&a/c doctor
These Renault dci engines are pretty reliable , but injector failure is a one issue . # 1 injector will be at the gearbox end .
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Tue 20 Feb 2024 10:33
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - Gordon the golfer

Hi Gents. are we certain that injector 1 is damaged and thats the reason for all the other lights?

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Tue 20 Feb 2024 10:42
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - elekie&a/c doctor
Clearing codes doesn’t fix a problem. System needs to be tested properly. You may also have a glow plug failure, but that wouldn’t cause a running issue .
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Tue 20 Feb 2024 11:22
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - Gordon the golfer

Thanks for the reply.

I'm wondering why the stop start and esc lights came on at the same time?

Are they related to the injector system?

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Tue 20 Feb 2024 11:37
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - elekie&a/c doctor
The s/s system will not function correctly if it detects a fault with the engine management system .
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Tue 20 Feb 2024 12:27
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - Andrew-T

Oh dear - posts like this make me glad I have a 2008 car without all those gizmos that have to have electronic perfection to avoid breakdowns ... :-)

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Tue 20 Feb 2024 13:11
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - edlithgow

Maybe stare at a wiring diagram for a while, with those things identified on it.

They dont seem obviously related functionally, but maybe the circuits share a connector which is wet, corroded or otherwise compromised.

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Tue 20 Feb 2024 13:49
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - elekie&a/c doctor
They’re not related , but that’s how the systems are designed in the modern car . On a lot of the Peugeot/ Citroen engined cars , if the oil filler cap is left lose , the cooling fan runs . What’s the idea of that ?
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Wed 21 Feb 2024 11:53
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - Gordon the golfer

Thanks. Where can i obtain a wiring diagram from?

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Wed 21 Feb 2024 12:53
2015 Renault Megane DCi - 2015 Megane broken down. Please help. - elekie&a/c doctor
There are a few options. Autodata or Haynes pro . Annual subscription about £900 or you can register on the Renault portal . If I recall , about €50 per hour.
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