fault code P0380

Problem with your Megane? Can't find an answer? Workshop manuals and technical notes are in here.

Moderators: q292u, Ray, AndyAdmin, Stranger

Posts: 1
Joined: Mon Aug 15, 2016 11:14 am
Currently Drives:: 56 megane cc 1.9dci

fault code P0380

Postby steve43 » Mon Aug 15, 2016 11:24 am

I have a 56 megane cc 1.9dci and get fault code P0380 on my elm 327 intermittent problem seems to come up when engine warm. Also car shakes when problem arises
Any thoughts please

Learner Driver
Posts: 79
Joined: Mon Oct 24, 2005 1:43 pm
Location: Norwich, UK

Re: fault code P0380

Postby Husky_Dog » Tue Aug 23, 2016 1:37 pm

Do you get any other messages on the display like "Check Injection'?

You might also want to check the environmental non-return valve on the top of the engine (located from the hose out of the oil filler point up to the top of the engine) if this becomes gunked up as blocks it can cause issues.

Other possible one to look at could be sticky EGR valve - how often has the oil been replaced over the life of the car?

The possible cause could be below - Glow Plug issue -->

P0380 - OBD-II Trouble Code
OBD II Fault Code

OBD II P0380
Fault Code Definition

Glow Plug/Heater Circuit "A" Malfunction
What does this mean?
The purpose of the Glow Plugs on a diesel engine is to heat up the combustion chambers to enable a quicker cold start. If the engine is already hot, the Glow Plugs aren't needed and will not 'light off'.

Code P0380 sets when the Power Train Control Module or PCM see less than 4 volts output to the Glow Plugs when the Glow Plugs should be energized or above 4 volts to the Glow Plugs when the Glow Plugs should NOT be energized.


Check Engine Light will illuminate
Failure of Emissions Inspections due to MIL malfunction
Vehicle may be hard to start
In rare cases, there are no adverse conditions noticed by the driver
Common Problems That Trigger the P0380 Code

Malfunction of the Glow Plug Relay
Malfunction of the GLow Plug Control Unit
Defective Glow Plugs
Defective wiring/connections in the Glow Plug wiring harness
Common Misdiagnoses

Glow plugs are replaced when the root cause is a defective Glow Plug Control Unit
Glow plugs are replaced when the root cause is a defective Glow Plug Relay
Glow plugs are replaced when the root cause is a defective wiring harness

P0380 Diagnostic Theory for Shops and Technicians
When inspecting for the cause of a Glow Pug circuit malfunction, I start by looking at the freeze frame data to get a picture of when the malfunction occurred. Then I use a data streaming scan tool and and zero in on the output voltage to the Glow Plugs. I'm looking for over 4 volts going to out to the Glow Plugs when I activate the Glow Plug warm up system. If there isn't, I locate the Glow Plug relay and test its function and its wiring harness. On systems where the Glow Plug relay isn't accessible, you have to test the Glow Plug Control Unit itself. Make sure the power and ground circuits going into and out of the Control unit have acceptable voltage drops. I look for .1-.2 volts (or less) on the ground side and .3-.5 volts (or less) on the positive side. I also check the Glow Plug harness for continuity by using a test light tethered to B+. I need to see bright illumination when I touch each of the Glow Plug harness connectors. This shows that the Glow Plugs and their wiring have solid continuity.

Good luck - let us know how you get on as its always nice to have feedback to help others in the future.

Kind regards,
2005 Scenic 1.9Dci 120 Exception

Return to “Problems / Questions”

Who is online

Users browsing this forum: No registered users and 45 guests