On Caterpillar machines — excavators, loaders, bulldozers, or gensets — the ECM (Engine Control Module) plays a central role. It manages injection, engine regulation, sensors, and even some hydraulic functions.
But when this electronic brain malfunctions, the symptoms can be varied, and diagnosing the issue becomes a real puzzle… unless you’re properly equipped.
👉 That’s where Jaltest INFO Web OHW makes a real difference: this online software gives you access to Caterpillar-specific technical data and guides you through ECM fault diagnosis and resolution — in record time.
⚠️ Common symptoms of a faulty Caterpillar ECM
These are the most frequent issues reported by CAT machine users:
- Check Engine light stays on
- Engine slows down without hydraulic pressure loss
- Engine stuck at low or high RPM
- Intermittent injection problems
- No communication with the ECM via diagnostic tool
In about 60% of cases, the issue is caused by a misread sensor or a software fault in the ECM — not a mechanical failure.
🧰 How does Jaltest INFO Web OHW help diagnose a Caterpillar ECM?
✅ 1. Identify Caterpillar ECM fault codes
Examples:
- E-ID:190-3 – Intake air temperature sensor: low voltage
- E-ID:111-1 – Low ECM supply voltage
- E-ID:232-2 – CAN communication fault between engine ECM and hydraulic ECM
💡 In Jaltest INFO Web OHW: enter the fault code → get a description, likely causes, and step-by-step solution.
✅ 2. Access complete Caterpillar ECM wiring diagrams
With interactive views, you can:
- Locate the ECM on specific machines (e.g. 320D, 950H, D6R…)
- Identify each connector, pinout, and expected voltage
- Trace connections between sensors, power supply, and ECM
🎯 Result: You test the right components without unnecessary disassembly.
✅ 3. Follow Caterpillar ECM-specific test procedures
Jaltest INFO Web OHW provides guided sheets to:
- Check electrical continuity between pins
- Test ECM power supply (9–32V depending on model)
- Measure sensor input values at the ECM
- Reset or recalibrate parameters after repair
✅ 4. Get a list of ECM-compatible CAT sensors
The software also provides:
- OEM references
- Normal operating values (range in V, ohms, Hz)
- Tolerances based on temperature or engine load
Example:
Fuel Rail Pressure Sensor
✔ Expected value (engine running): 28,000–35,000 kPa
✔ Voltage: 0.5 V (idle) to 4.5 V (full throttle)
🧪 Real-life case: ECM fault on Caterpillar 320D excavator
🔧 Symptoms: Check engine light + unstable idle + fault code E-ID:94-1
🔧 Diagnosis with Jaltest INFO Web OHW:
- Fault code read
- Engine RPM sensor test → OK
- ECM power supply test: 7.6 V instead of 12 V → ground issue
🔧 Fix: Connector cleaned, fuse replaced, fault code cleared → normal operation restored
💼 Direct benefits for your Caterpillar workshop
| Before Jaltest INFO Web | With Jaltest INFO Web OHW |
| Blindly searching for diagrams | Instant, precise schematics |
| Trial-and-error sensor testing | Clear, guided procedures |
| Diagnosis time: >2 hours | Average time: 30 minutes |
| Risk of wrong diagnosis | Reliable, multi-model data |
| Dependent on scan tool | Usable even without interface |
✅ Conclusion: ECM faults won’t catch you off guard anymore
With Jaltest INFO Web OHW, you have everything you need to work confidently and efficiently on Caterpillar ECM issues.
✔ Save time
✔ Avoid unnecessary part replacements
✔ Reduce stress on the jobsite📞 Request your free trial now in just a few clicks
