Help. I know just enough about cars to get myself in trouble. Engine itself ran awesome. My problem started with my 2000 300M going into limp mode. Codes p0700,0750, p1768,p0731. Changed speed sensor . After a few miles went back to limp mode. Checked relays, before having someone get into my tranny (have no money) I changed the TCM (used) . Car Barely ran after that. So changed back to old TCM. Turned over, ran a few seconds. Then nothing not even a click. Please Help a poor girl. My only car and stuck 29 miles from town
1768 Power and ground Issues. If the engine wont even crank/start check all Battery, jump post and ground post connections by removing, cleaning and tightening them. Also check the connectors for the trans near/under the brake booster/master. 2 Grey connectors and harnesses that are near the tie rods.
731 Usually Speed sensors (2) did you change both? OEM ?