Infamous ‘Check Engine’ light is on for my ’94 SL500. Have tried a couple simple things including a new wiring harness (it needed it anyway), new gas cap, tune-up, etc. – all to no avail. If I reset the CEL, it will remain off through 3 or 4 engine starts. Then during the 4th or 5th engine start, the CEL will remain illuminated – the CEL never comes on while driving. If I reset the CEL again, the same sequence repeats. Also, the car runs great and gets reasonable gas mileage (~15 mpg). It even passes smog checks as a very clean vehicle - as long as I reset the CEL immediately before the inspection.
With no OBDII port, there is no straight-forward way to retrieve diagnostic data. I know there are methods for a DIY guy to this and would appreciate hearing from folks on how I can retrieve diagnostic data from a ’94 SL500. Thanks in advance.
Cheers,
Jeff