Exhaust Air Flap Function

Forum for Engine, Exhaust, Drivetrain, ECU
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thompson182uk
Posts: 1
Joined: Mon Feb 22, 2021 2:12 pm
Qashqai Model: Mk.2 Qashqai - J11 (2013–2017)

Exhaust Air Flap Function

Post by thompson182uk » Mon Feb 22, 2021 5:32 pm

Hi guys,

First time poster here, I have a 1.5 Diesel.

A couple of weeks ago my Engine Management Light came on solid orange, so I booked it in to a local garage for diagnostics.
However the day of the test the light had gone off... but they did find 2x 'past' fault codes (P1480 and P148C) in the system.
Both of these are related to the "Exhaust Air Flap Function".
I was told this is something that I need to get done at a dealer and I'd be looking at around £700-£800 for parts and labour.

Since the light was off I thought I'd monitor and and hope it won't come back on. Anyway a week or so later, the light has returned!!

I'm now hearing, or just noticing, a "hollow hissing/grinding, airiness" noise when revving:


I now also get a message every 20-30 seconds that says: "Stop/Start System fault", followed immediately by a message saying "Stop/Start on".
So I've turned 'stop/start' off for now to stop these messages coming on. But I daresay the stop/start fault is related to the warning light and the exhaust noise?

I think I managed to get the "hissing" to stop by taking it a few extra motorway junctions on my way home to get some miles in at high revs. But the noise has since returned and seemingly getting worse... Due to COVID I'm doing very little miles so my first though is that the DPF is clogging up!? Hence why I've done the motorway driving.

The roads around me have also been heavily gritted and salted of late, and the cold weather is when the problem started... so not sure if that's done something.

I'm hoping this will fix itself after a few miles of unclogging... something, or should I just take it to the dealer and accept my fate :(

Any ideas would be greatly appreciated.

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gloucester
Posts: 2868
Joined: Sun Apr 03, 2016 7:04 am
Location: Gloucestershire, England
Qashqai Model: Mk.2 Qashqai - J11 (2013–2017)

Re: Exhaust Air Flap Function

Post by gloucester » Tue Feb 23, 2021 8:57 am

Welcome to this forum.

Sorry can't help but hopefully someone will be around soon.
(2015 Nissan Qashqai Tekna DIG-T 1.2 sold 15/6/18) ~ 2018 Suzuki Ignis SZ5 - 2018 Yamaha MT-07

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calnorth
Posts: 1955
Joined: Mon Feb 11, 2019 2:01 pm
Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–present)

Re: Exhaust Air Flap Function

Post by calnorth » Tue Feb 23, 2021 9:46 am

I'm not familiar with diesel engine exhaust systems. The two DTCs you show are relevant to:

P1480 EXHAUST ELECTRIC THROTTLE CONTROL ACTUATOR -
Component Inspection (Exhaust Throttle Control Motor)
Component Inspection (Exhaust Throttle Position Sensor)

P148C EXHAUST ELECTRIC THROTTLE CONTROL ACTUATOR -
Component Inspection (Exhaust Throttle Control Motor)
Component Inspection (Exhaust Throttle Position Sensor)

Not sure why they flag the same errors twice but exhaust gas control appears to be defective.

A post for Xtrail elsewhere describes as follows:

(1) The valve closes to create back pressure to allow low pressure EGR to aid reduction in NOx
(2) When valve opens after low pressure EGR it creates a strong pressure wave to expel gasses through exhaust system creating a scavenging effect
to help move carbon particle through exhaust system.
(3) Because of the back pressure in exhaust it also helps to increase temperature within exhaust system to increase temperature within catalytic converter and DPF.
(4) Any fault/failure with the Exhaust electric throttle control actuator could have a detrimental effect on other parts of the exhaust/EGR systems.
Mk2 Qashqai Facelift - J11b (2017–present)
1.6 Dig-T N-Connecta

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