CEL without code 1994 NAS D90 3.9

[wrc3]

So occasionally my truck will light the CEL but there is no code shown. If I turn the truck off and back on again the CEL is gone. Any ideas?

 

[ionfender]

Where are you looking for the code?

The code display is a rectangular box (slightly bigger than a pack of smokes) that is typically in the passenger seat box or up against the firewall/bulkhead in the passenger footwell. The box sometimes gets relocated based on prior modifications.

If you have A/C it can sometimes get hidden in the passenger footwell behind the A/C lower dash facia.

 

[wrc3]

Thanks. Ya I know where to look. I have pulled codes before for a bad O2 sensor.

Also when I had the bad O2 sensor it took me disconnecting the battery to reset the CEL. This time simply turning the car off and restarting clears the light, so definitely something different than a regular CEL.

 

[rocky]

The delights of Pre OBD2 cars……

 

[Robert]

try pulling the codes with rovergauge. the readout on mine has become flakey with age

theres also a code set anytime the battery is disconnected. could that be it?

 

[jymmiejamz]

The display probably isn’t working

 

[wrc3]

Rovergauge it is. Just wanted to see if anyone else has had a similar issue.