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VOLVO
DEM-0001
DEM-0004
DEM-0007

DEM-0001, DEM-0004, DEM-0007 Volvo – Haldex Gen 2 DEM Power Electronics Diagnostic Guide

Diagnostic Priority: High
Complexity Level: Advanced

Technical diagnostic guide for Volvo P2 XC90 V8 / D5 covering DTCs DEM-0001, DEM-0004, DEM-0007. Factory measurement tolerances and 1:1 Cloning solutions.

Vehicle

VOLVO

Codes

3 units

Analysis Type

Technical Expert

Status

Analyzed

Technical Analysis

REF: #8DC9F6

The fault code combination DEM-0001, DEM-0004, DEM-0007 on Volvo P2 XC90 V8 / D5 points to a validated mechanical or sensor failure requiring systematic diagnostic verification.

Expected Symptoms

Dashboard message "AWD disabled / Service required" illuminated (DTCs: DEM-0001, DEM-0004, DEM-0007)
Front wheels spin freely on acceleration with zero torque transferred to rear axle
AWD/DEM supply fuse (typically 7.5A in rear fuse module) blows under pump load

System Impact

Drivetrain
Engine Control
Emission Control

Potential Fault Sources

01Choked Haldex pump V181 filter screen causing overcurrent and internal DEM power stage failure (affecting circuit for DEM-0001, DEM-0004, DEM-0007)
02Mechanical wear and armature short-circuit in Haldex pre-charge pump motor
03Moisture and road salt corrosion at the DEM differential harness connector (logged fault: DEM-0001)

Workflow / Methodology

01

Verify supply voltage and reference ground for DEM-0001, DEM-0004, DEM-0007 with multimeter at key ON.

02

Verify DEM power supply fuse condition in rear electrical module (REM).

03

Measure pump operating current during activation: 1.5–2.8 A normal, >3.8 A indicates defective pump.

04

OBD Tuning performs 1:1 Complete Bench Cloning of the DEM module to a refurbished replacement unit.

Live Data & Mätvärdestoleranser (Är/Bör-värden)

Fabriksgodkända referensvärden vid diagnos och live-avläsning

Mätvärdesblock
Parameter / SignalTestvillkorBör-värde (Normalt)Avvikelse / Varning
DEM InterntestTändning påNormal / GodkändInternt hårdvarufel
Haldex Matarpump StrömAktiv fyrhjulsdrift1.5 – 2.8 A> 3.8 A (Överbelastad pump)
Haldex KopplingstryckFull inkoppling30.0 – 38.5 bar< 20.0 bar

Assessment & Action Proposal

Technical Recommendation

1:1 Cloning of Haldex Gen 2 DEM-control module at OBD Tuning.

Need a deeper analysis? Use our advanced fault code analyzer to find likely connections and in-depth guidance.

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Vanliga frågor om dessa felkoder

Vad är den primära orsaken till felkoderna?

The fault code combination DEM-0001, DEM-0004, DEM-0007 on Volvo P2 XC90 V8 / D5 points to a validated mechanical or sensor failure requiring systematic diagnostic verification.

Kan man köra vidare med tänd motorlampa / varningslampa?

Körning med aktiva felkoder kan leda till strypt motoreffekt (nödläge / Limp Home), blockerad partikelfilterregenerering eller följdskador på mekaniska komponenter. Felsökning bör genomföras omgående.

Hur åtgärdas kombinationen på säkrast sätt?

1:1 Cloning of Haldex Gen 2 DEM-control module at OBD Tuning.