Applicable Systems
EC220 Excavator
Symptoms
Dashboard shows false low coolant level; actual level is normal.
Possible Causes
- Coolant level sensor float stuck in down position.
- Sensor connector corroded giving false low resistance.
- Harness pinched between frame and cab causing intermittent short to ground.
Troubleshooting Steps
- Step 1: Remove sensor and move float manually; check resistance change.
Resistance changes smoothly 80–300 Ω across float range. - Step 2: Check connector pins for green oxidation.
Pins bright; dielectric grease present. - Step 3: Inspect harness routing along left frame rail.
Harness free in loom; no pinch marks or chafing.
How to Reset
Replace coolant level sensor; repair connector; reroute harness if chafed.
Common Replacement Parts
- Coolant Level Sensor 11713593: Coolant Level Sensor 11713593
Frequently Asked Questions
- Q: Can I drive with this fault?
Yes, but monitor sight glass manually; fix soon to avoid ignored real low level.
- Q: Why do floats stick?
Coolant deposit buildup or mechanical interference from installation angle.
Source: Volvo L120H Electrical Schematic Manual
Category: Heavy Equipment