Add blue and airbag issues after air install

J99kom87

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Hi everyone, can anyone help me with what’s going on with my add blue and airbag issues please?

I recently installed air suspension all underslung, once I’d finished the wiring including reconnecting the battery etc, I tried starting it and the battery had ran low, so had to jump start it initially (negative to chassis, positive to terminal) and then left it on charge for a couple of days via my victron charger.

On initial start up I was greeted with an air bag light and a EML light.

I read the codes via obd eleven and it’s showing the following


Reductant Control Module Power Relay

De-Energized Performance - Too Early

Lost Communication with Reductant Quality Module

Reductant Pump "B" Control Circuit Low

Airbag passenger side ignite b100a11.

Yesterday it had the EML light on and 3000mile add blue to refill message, but today it suddenly dropped to the 650 mile warning, I haven’t refilled as of yet due to the fact it was on 3k yesterday.

As for the airbag I’m running g aftermarket Astra gsi seats with a resistor in the plug and have down for the past year with no issues.

It this just coincidence of is there a possibility I’ve done something and where the best place to start looking? Is there a fuse to check etc? The undertrays are still currently off the van but I haven’t had chance to get underneath it again.

Apologies for the long thread.

Thanks

Mark
 
Maybe VCDS scan would be an ideal place to start and go from there. How old is your battery ?
 
Did you clear the fault codes to see if they return? (in case they were generated due to low battery voltage)
 
OBDeleven data log

Date: 2025-11-02 10:56

VIN: WV2ZZZ7HZJH1
Car: Volkswagen Transporter
Year: 2018
Body type: VAN
Engine: CXFA
Mileage: 104600 KM

---------------------------------------------------------------
01 Engine

System description: R4 2.0l TDI
Software number: 04L906056KH
Software version: 5952
Hardware number: 04L907445
Hardware version: H02
ODX name: EV_ECM20TDI03004L906056KH
ODX version: 004012
Long coding: 0025401C432401080000

Trouble codes:
P20EA00 - Reductant Control Module Power Relay De-Energized Performance - Too Early
static
Date: 2085-01-21 10:09:00
Priority: 2
Malfunction frequency counter: 1
Unlearning counter: 255
Unknown ambient data: 00000000683D622EF771209628445400693B4E00007027000029AA0058197A00C541D602
U02A200 - Lost Communication with Reductant Quality Module
static
Date: 2085-01-21 10:07:21
Mileage: 104593 km
Priority: 2
Malfunction frequency counter: 1
Unlearning counter: 255
Unknown ambient data: 1AADE022693F623020712096283F6504384454006444C9153344A7161B58210000000058220000000058B2000041E30000
P20FC00 - Reductant Pump "B" Control Circuit Low
static
Date: 2085-01-21 10:06:21
Mileage: 104593 km
Priority: 2
Malfunction frequency counter: 1
Unlearning counter: 255
Unknown ambient data: 00000000683D622EF771209628445400693B4E00007027000029AA005829AE000041D606
 
My gut feel is that it is a wiring issue (possibly between the Adblue relay and the pump) especially if you have been doing wiring cjhanges for the suspension.
 
My gut feel is that it is a wiring issue (possibly between the Adblue relay and the pump) especially if you have been doing wiring cjhanges for the suspension.
I got back underneath yesterday and I can’t see anything that’s been disturbed or damaged etc it’s really strange
 
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