My check engine light came on and my truck is idling a little rough. I need to see what codes it's throwing. I haven't had to deal with this before. How do I read codes? Can I borrow a gauge at an auto parts store?

 

What year is your Discovery? If it's a '94 or '95 there is a digital code reader under the passenger seat. With the key in the II position it will display in red LED the code numbers for faults in the engine management system. If it's a '96-'99 you need an OBDII code reader. There is a port for plugging the reader into the vehicles system above your left shin as you sit in the driver's seat.

If you have an OBDII system you have a wide variety of code readers available from well under $100 on up to hundreds of dollars. Which one you choose depends on how serious you are about doing your own repairs. Some of the auto parts stores may still lend out code readers for customers to do diagnostics. You'll have to see if the stores in your area still do that.

 

Depends on the year of your DI. 94 -95 it's OBDI and the "Code Reader" display is under the passenger seat. Looks like the pic

> Land Rover Troubleshooting: retrieving fault codes

1996 and on is OBDII, so yes you can have it scanned at any Auto Zone, Advanced, etc.

 

OK got it. What do I do with this?

 

Read it. A numerical code will be displayed in red on it.