Nissan Pickup Speedometer Not Working And Check Engine Light

Finding your web site is like stumbling on an old friend again. Glad to see you back! I was talking with my girl friend while she was driving her 1994 Nissan Pickup. She said that her speedometer quit working and the check engine light came on. Then, before she stopped driving, the speedometer came back on and the CEL went off. How should I start to trouble shoot this? Any particular ideas?

Start with the sending unit on the transmission. All vehicles today have computer driven speedometer systems, no more speed cables and simple gear driven odometers these days. Often the sending unit on the transmission breaks down, and this will set the check engine light on because the computer knows this. It can also set other lights a flashing, because they are all interrelated in computer systems. You could of course have a wiring problem or a dash unit problem in the speedo system, BUT the sending units going out is the Number One problem in Nissans.