On this page, you’ll find a short video outlining the procedure for manually testing an engine coolant temperature sensor.
ECT Testing Tools
Here I’ve listed some tools to help you diagnose and fix a troublesome engine coolant temperature sensor. All diagnosis should begin by reading PCM fault codes. Even a basic scanner is capeable of reading ECT fault codes and observing ECT activity in real time. A scanner is always worth having in your glove box, I’ve listed two scanners here, the Topdon (inexpensive) and a higher end Autel.
Fluke DVOM (Digital Volt Ohm Meter) also known as Multimeters or Voltmeters are leaders in the game and this one is a surprisingly good price. Fluke is a pro tool and will acutely measure volt drops and resistance, both critical measurements for fault finding components or circuits and increasingly so as the world of transport turns electric. Picture links to Amazon.
Professional back probes are important when diagnosing sensitive and delicate automotive terminals. Jamming a DVOM probe into a terminal is a seriously bad idea, it will spread the contacts and that causes a ton of problems.
The Topdon is a great little fault code scanner, I’ve used it and reviewed it and it works like a charm. You can read and clear codes, observe various sensor readings in real time. Picture links to Amazon. I wrote review of the Topdon here – Topdon vs. Autel.
The Autel MaxiCOM is a shop-level tool. It is capable of reading, clearing fault codes, coding a new battery, placing EPB module in service mode, and calibration after the repair. It is also capable of activating ABS modulator solenoids when performing a full brake bleed procedure. Picture links to Amazon.
A Power probe is an excellent tool to have around. Great for testing circuits, relays, fuses, checking battery voltage, checking alternator output, checking the ground, volt drop testing. I’ve had a power probe forever and it’s still going strong. Picture links to Amazon.
Coolant System Maintenance Tips
Your coolant system needs regular maintenance, in terms of critical systems, it’s second only to engine oil. So what type of maintenance does a coolant system require? That depends on the type of vehicle, how it’s used and where it works or lives.
A truck that works hard towing, maybe in dusty off-road conditions will require a ton more maintenance than a regular family car, no surprise there.
Anyhow here’s a list of maintenance tips that will prevent your engine from freezing in winter and overheating in summer.
- Check coolant with every fill of gas
- Top coolant up with coolant, avoid using water if possible
- Check antifreeze strength of the coolant well before winter arrives (antifreeze is an agent added to coolant and so some folks call it antifreeze and some coolant)
- Replace serpentine drive belt every four years (drive belt drives the water pump in chain driven engines)
- Replace coolant system reservoir cap every four years
- Replace thermostat every four years
- Replace water pump every four years
- Backflush coolant system every four years
- Replace coolant every four years
- Check radiator for debris and clean regularly with compressed air in dusty conditions (off-road driving especially)
- Check for leaks under the vehicle and around coolant hose pipe clamps (usually easier cheaper to find problems before they find you)
You’ll find a ton of tools on the coolant system maintenance tools page that will help you maintain, diagnose, fix and test the system.