Photos by Justin Pritchard and courtesy Lemur Monitors

A lot has changed in the world of engine technology in the past few decades – including the prevalence of networked sensor arrays that give today’s powerplants continually optimized operation that turns in the mileage and environmental performance that shoppers (and governments) demand.

These sensors, like all parts of a vehicle, will eventually wear down, act up, fail, and require attention. Sometimes, the presence of a worn-out sensor is obvious – for instance, evidenced by an engine that’s running poorly, or not at all. In other situations, a worn-out sensor may not give itself away, though it could be causing the vehicle in question to emit more pollution, to consume more fuel, or to run like an obese sloth.

Some sensor-related issues will result in a Check Engine light illuminating in the instrument cluster. This warning light is an invitation from your ride to scan its computer brain, which will reveal which sensor(s) are acting up. Thing is, some sensors can begin to act up or fail without causing this light to illuminate at all. To most shoppers, then, vehicles with wonky sensors and no check engine light illuminated are hiding a great big secret. Even the vehicle’s seller may not be aware that they’ve got one or more engine control sensors that are out of whack.

Lemur BlueDriverLemur BlueDriverLemur BlueDriver
Lemur BlueDriver. Click image to enlarge

Solution? Shoppers can scan the computer brain of the vehicle they’re considering easily and quickly, for a glimpse at the health of the machine’s all-important sensor network. Used to be that completing this scan required visiting a mechanic or parts store to hook up a special instrument to the vehicle’s On Board Diagnostics (OBD) port. Then, prices on these scanners came down and numerous hand-held options were available, somewhat affordably.

Now, these scanners are smaller, more portable and more easy to use than ever – with a variety available that use Bluetooth to link, via an app, to the user’s smartphone.

One such example is the BlueDriver, from Lemur.

About the size of a small container of Tic Tacs, the Bluetooth-enabled device is powered by the OBD port itself and links wirelessly to the user’s phone. It’s compact and there are no wires, making the unit about as portable as a set of keys.

Lemur BlueDriverLemur BlueDriver Vehicle InfoLemur BlueDriver Engine Coolant TemperatureLemur BlueDriver Trouble Codes
Lemur BlueDriver, Vehicle Info, Engine Coolant Temperature, Trouble Codes. Click image to enlarge

On a test-drive of a potential used ride, the shopper can simply plug the BlueDriver into the OBD port of the potential used ride candidate, open the app on their phone, turn the vehicle’s key, and wait for the scan results – which take about five seconds to populate, or a bit longer on older vehicles with slower computer systems. The whole scanning process, once you locate the OBD 2 port (it’s usually within about a foot of the base of the steering wheel, tucked up and out of the way beneath the dash) should take less than a minute.

Once the results appear on screen, you’ll have a secret look into the computer network of the vehicle in question. Hopefully, there are no codes – that is, no sensors out of whack. Maybe, there are numerous codes, meaning numerous sensors need some attention, adding to the near-future costs of operating the vehicle in question.

In any case, it’s better to know. And not only does the BlueDriver app tell you if, and what codes are present, but it can explain what the codes mean, which sensors are affected, and even gives the driver access to available Repair Reports, which highlights similar codes and suggested fixes from other users based on the same codes in the same vehicle. Further, the device can read non-current codes, revealing a past problem, and pending codes, which reference a sensor issue that’s not severe enough to log a hard code – yet.

Manufacturer’s Website:
Lemur Monitors

Photo Gallery:
Lemur BlueDriver

Paul Kenealy is a mechanic. He explains “an inexpensive code reader can be a valuable asset when shopping for a used car. Even if there are no check engine light visible, the PCM may have codes that are applicable now, or show codes stored from past issues. Not all codes mean there is a serious problem with the car however, as something as simple as a loose gas cap can set it off. Other codes could point at pricey repair bills.”

The BlueDriver is available from or on for about $100.

Connect with