No Computer Codes Reading Out

[ceevester]

I have a 2000 Safari, 4.3L and it has been intermittently hard to start lately.

I took it to an Advanced Auto Parts store to get them to scan the computer codes and they couldn't get anything even though they tried two scanners.

A friend came over and tried his scanner and he couldn't get any codes to read out either.

Why would this happen? If the computer wasn't working, the engine wouldn't run would it?

[rustymac]

Not always. You might just have a communication problem with one of the other onboard computers. Try with the key on, turning the headlights on, then turn your high beams on, then with the high beams still on turn the high beams off. If the high beam indicator remains lit on your dash board, you have a communication problem some where. Good luck.

[ceevester]

Originally Posted by rustymac

Not always. You might just have a communication problem with one of the other onboard computers. Try with the key on, turning the headlights on, then turn your high beams on, then with the high beams still on turn the high beams off. If the high beam indicator remains lit on your dash board, you have a communication problem some where. Good luck.

Thanks for the tip Rustymac, I tried what you suggested, but everything seemed to work okay.

I bought a used ECM and installed it. The problem is, it has to be programmed to my vehicle. When I tried to start it, it would start, but then immediately stall out, so I couldn't drive it to the shop to be programmed.

It seems these vehicles have something called "Pass/lock", as a security feature, and if the ECM isn't programmed to YOUR vehicle, or the wrong key is used, it shuts off fuel to the engine.

However, there is a little trick you can use if this were to happen to you while on the road, or if you install a new ECM.

What you have to do is, turn the key on as usual, them just "bump" the engine with the key to "start" but DON'T START IT.

Leave the key on for 10 minutes. The "security" light on the instrument cluster will go out after 10 minutes.

Then, turn the key off for 5 seconds.

Then repeat the "Bump" routine and leave the key in the run position for 10 more minutes. The security light will again go out after ten minutes.

When the light goes out, turn the key off again for 5 seconds.

Then repeat the engine "bump" routine again.

After 10 minutes, when the "security" light goes out again, turn the key off.

Now, wait 5-10 seconds and start the engine as usual.

My engine started fine, and I took it to the shop for reprogramming. So far everyting is working well.

I realize some folks might not like me telling how to defeat this little "jewel" of security, but sorry, this board is for helping fellow motorists and not having to pay a tow truck when every little "feature" on these modern vehicles malfunctions.

Maybe it will help someone out and save someone a hassle and some money.