U0139: Perte de communication avec le calculateur B de suspension
Que faire
Look at the car from a few metres away before you drive it. If it is sitting low, or low at one corner, do not drive it — have it recovered.
This is the second of your car's suspension computers, and it has stopped talking to the rest of the car. On an air suspension that usually means the system can no longer keep itself pumped up.
Air suspension does not fail suddenly; it sinks. The bags always leak slightly and the compressor always tops them up, so when the topping up stops, the car settles over a few hours or overnight.
A car sitting on its bump stops has no suspension left at all. The ride is violent, the tyres can catch the arches, the headlights point at the road, and it does not handle the way anything about it was designed to. That is worth a recovery truck rather than a careful drive home.
Two things that save money. If the compressor is running constantly and the car still will not stay up, stop driving it — a compressor fighting a leaking air bag overheats and burns out, which turns one repair into two. And ask about a transport or jacking mode: most of these cars have one that holds a fixed height for recovery, which is far better than dragging a settled car onto a trailer.
Ask for the compressor's relay, fuse and earth to be checked first. They are the commonest cause and the cheapest.
Ce que signifie ce code
A second suspension control module has stopped being heard from. The general reasoning is at U0100; module A is at U0132, and U0421 covers the same family reporting implausibly instead.
A vehicle carries a second suspension module when the job has been split — commonly one per axle on a full air suspension, or a separate controller for the compressor and reservoir alongside the module that decides ride height. So this code usually means one end of the vehicle, or the air supply itself, has gone quiet.
Which produces the failure this page exists for: a vehicle that settles. An air suspension that cannot run its compressor does not fail suddenly — it sinks, over hours or overnight, as the bags leak the small amount they always leak and nothing replaces it.
A vehicle sitting on its bump stops has no suspension travel at all, and that is a genuine limit rather than a comfort complaint: the ride is violent, the tyres foul the arches on compression, the headlights point at the ground, and the handling is not what any part of the vehicle was designed around. If the vehicle is visibly low, or low at one corner, it should be recovered rather than driven.
One end low and the other normal is the signature of a split system and points straight at which module or which circuit is involved — worth photographing before it is moved.
Two practical notes that save money.
- Do not keep driving a system that is trying and failing to hold height. A compressor working against a leaking bag runs continuously, overheats and burns out — turning a bag repair into a bag and a compressor.
- Many vehicles have a transport or jacking mode that holds a fixed height for towing and recovery. Ask for it; it is much better than dragging a settled vehicle onto a trailer.
Where the fault is: the compressor and its relay live under the vehicle or in a wheel arch, and their supply is the single commonest failure in the whole system — a relay, a fuse, or a corroded earth, all cheap.
Causes probables
Commencez ici
- Fusible grillé ou alimentation hors service · facile
- Connecteur corrodé ou mal enclenché · facile
- Infiltration d'eau dans le connecteur du calculateur · modérée
- Faisceau de câblage endommagé · modérée
Moins fréquent
- Connexion de masse corrodée · modérée
- Câblage du bus de données endommagé · modérée
Symptômes
Composants concernés
Des informations, pas des instructions
CarGeek est un ouvrage de référence, pas un manuel d'atelier. Ses pages sont rédigées à partir de sources publiques et de ce que d'autres ont constaté, jamais à partir de la documentation technique du constructeur ; elles peuvent donc être erronées ou incomplètes pour votre véhicule précis. Une partie de ce qu'elles décrivent présente un risque réel : haute tension, carburant sous pression, énergie accumulée, pièces chaudes ou en mouvement.
Avant d'agir sur quoi que ce soit, faites-le vérifier par une personne formée, en suivant la procédure du constructeur pour votre véhicule. Rien ici ne remplace cette procédure.
Expérience de la communauté
Soyez le premier à en faire le compte rendu
Rien n'a encore été publié à ce sujet. Tout ce que vous avez trouvé mérite d'être noté — même une impasse épargne à quelqu'un le même après-midi.
Ce qui rend un compte rendu utile :
- La voiture — marque, modèle, année et moteur. La même panne ne se comporte pas pareil sur chacune.
- Ce que vous avez mesuré, pas seulement ce que vous avez remplacé.
- Ce qui a réellement résolu le problème — ou que rien ne l’a résolu, ce qui est utile aussi.
Se connecter ou créer un compte pour ajouter ce que vous avez trouvé à propos de U0139.