In all likelihood it’s just the connection between the sensor that sits in the middle of the shifter and the automatic transmission. This sensor will cause the Check Engine and Check Gearbox lights to come on simultaneously. Your Saab will also drive really slow and you’ll probably be afraid your transmission went out or is about to go out or that you blew a gasket.
Most likely not.
This sensor is filled with a heavy grease and sometimes on hot or cold days the grease gets fudged up. When the contacts aren’t touching it sends a signal to the on-board computers that something is wrong in your transmission and this puts your car into “limp mode”. No turbo, no 4th gear, no high performance settings. Congratulations, you now drive a very slow Yugo.
Changing this sensor could cost you over $500.
Try this instead:
- Start car
- Put into drive (with foot on brake)
- Turn off car
- Turn key to the on position but do not start it
- Move the shifter from Park to 1st gear (up and down) about 5-10 times at medium speed
- Turn key to off position and Start, or Turn to off, remove key for a few seconds and replace it and start
What you are doing is cleaning the sensors and also increasing the viscosity of the aforementioned fudgy grease in the sensor. The lights should go off and your car should be restored.