Applicable Systems
EC220 Excavator
Symptoms
ECM sensor +5V supply voltage out of range; multiple sensors may report incorrect readings simultaneously.
Possible Causes
- ECM +5V regulator failure
- Sensor supply wire short to ground
- Faulty sensor loading +5V supply
Troubleshooting Steps
- Step 1: Measure +5V supply at ECM sensor connector
+5.0V stable - Step 2: Check for short to ground on +5V line
No short - Step 3: Disconnect sensors one by one to isolate
Voltage restores when bad sensor disconnected - Step 4: Replace faulty sensor loading supply
+5V stable with new sensor - Step 5: Clear code and verify all sensors
All sensors reading normal
How to Reset
Clear via Volvo Tech Tool after sensor/supply repair.
Frequently Asked Questions
- Q: How many +5V sensor supplies does ECM have?
Typically 2-3 separate +5V supplies to isolate sensor groups. One shorted sensor won't disable all sensors. Check wiring diagram for supply grouping.
Source: volvo fault codes reference
Category: Heavy Equipment