Meter, Scope and Automotive Circuit Tests in One Handheld
The DM303 combines a True RMS auto-ranging multimeter and oscilloscope with dedicated cranking, ignition, injector, relay, signal-output and K/CAN line modes for car, truck, bus and EV circuit work. Batteries are not included.
- DMM + oscilloscope
- 12 fonctions de test
- Courant de commande 5 A
- 6 types de cordons de test
- Écran couleur de 2.8-inch
Key Features
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Instrument à valeur efficace vraie et sélection automatique de gamme
DC/AC voltage, current, resistance, diode and frequency, with auto range to cut manual range selection.
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Contrôles de démarrage et d’allumage
Records minimum battery voltage during starting and views ignition pulse signals.
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Test des injecteurs et des relais
Drives supported electromagnetic injectors, including supported GDI injectors, and reads real-time injector signals; also tests relays.
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Signal Output
5 V square, 5 Vpp sine and 12 V square outputs for signal simulation on a documented, permitted load.
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Données des lignes K/CAN et K/LIN
Views bus line data for circuit-level diagnosis.
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Kit dans une boîte à outils
Rear stand for upright viewing, built-in flashlight, and a toolbox that holds the meter and leads together.
Autres caractéristiques
| Signal de commande d’injecteur | 500–6000 rpm |
|---|---|
| Data hold | Data lock and clear |
| Langues de l’interface | Including English, French, Portuguese, Polish, Spanish, Japanese, Russian, Italian, German, Dutch, Korean and Chinese |
| Batterie au lithium en option | 503450 3.7 V 1000 mAh style shown in the reference image; confirm connector and size before fitting |
DM303 vs DM301
| DM303 | DM301 | |
|---|---|---|
| Functions | 12 | 6 |
| Types de cordons de test | 6 | 2 |
| Courant de commande du circuit | Sortie 5 A / entrée 5 A | No |
| Signal de commande d’injecteur | 500–6000 rpm | No |
| Modes de test ajoutés | Injector, relay, circuit, cranking, signal simulation, CAN and K/LIN line data | Voltage, current, resistance, frequency, oscilloscope, ignition pulse only |
Contenu du coffret
- Multimètre de diagnostic automobile DM303
- Boîte à outils portable
- Cordon de test multifonction
- Câble à pince de batterie
- Sondes de multimètre
- Câbles de pontage et d’adaptateur
- Cordons de test supplémentaires
- User manual

How to Use
- Définir la mesureUse the wiring diagram to identify the expected signal, reference point and safe mode.
- Inspectez les cordons et les valeurs nominalesConfirm the terminal, fuse, lead and probe ratings for the task.
- Sélectionnez le modeChoose the function and start on a safe range.
- Vérifiez la compatibilité de toute sortie activeBefore injector, relay or signal output, confirm component type, pinout, supply, current and permitted mode.
- Sondez le circuitConnect to the correct reference and test point without bridging terminals.
- Notez et vérifiezNote the value, compare it with the vehicle specification and recheck before naming a root cause.
Modes, plages et sécurité : Manuel d’utilisation DM303 (PDF).
Good to Know
Attention
- Batteries are not included. Use 4 × 1.5 V dry batteries or a compatible lithium battery, purchased separately.
- Never charge dry batteries in the device; only a compatible rechargeable lithium battery may be charged.
- Keep injector drive and signal outputs off ECU outputs, SRS circuits, powered data lines and unknown modules.
- Les injecteurs 120 V ne sont pas pris en charge.
FAQ
What does the cranking test result mean?
The DM303 records minimum battery voltage during starting and uses 9.6 V as a general reference. A lower reading can point to a weak or aging battery or a starting-system issue; apply the battery or vehicle maker’s procedure.
Can it replace a full vehicle diagnostic scanner?
No. K/CAN line data helps with circuit-level diagnosis, but it is not a full vehicle scan.
Does a drive response prove an injector is good?
No. It does not by itself prove spray pattern, flow or root cause.




































