The check engine light came on in my 1995 S420. The technician pulled Code 26 from his diagnostics. He said that this is Upshift Delay. What exactly is upshift delay, what causes it, and how is the problem fixed ? Any help that is offered will be greatly appreciated.

 

a valve that is on the right side of the transmission above the trans oil pan. it has vacuum hoses going to it and a cable that goes to the throttle linkage. controls the trans upshift delay, to heat the cats in the morning.

 

What exactly has to be done to fix the problem ? Is it harmful to drive the car with this condition existing ?

 

the upshift delay needs to be replaced...or there is a vacuum line off of it. its located on the right side of the transmission above the oil pan and is right up against the tunnel and is tough to get to... usually you have to remove the trans pan to attach the cable and you need to adjust the shift points with the screw on the back side of the upshift delay ....just compare the distance the scew is backed out from the old one to the new one.