Overdrive light flashes

C-BYRD

MEMBER
1999 FORD RANGER
4.0L
V6
4WD
AUTOMATIC
158,509 MILES

Just recently purchased this truck. Great condition but overdrive light flashes and shifts hard after the truck gets hot. I’ve replaced the VSS on top of back axle and replaced the OSS (I think that’s the name) on topside of transmission at the rear and still the same outcome. Feels like I'm actually acting out the definition of insanity. Please speak in a manner I can understand because I’m not a mechanic and I don’t have a scanner. Thank you for any advice!

1 Reply

DANNY L

MECHANIC
5,648 POSTS

Hello, I'm Danny.

Unfortunately, you mentioned you don't have a scanner but at this point that is what is needed. Having the overdrive light flashing means a transmission fault code or codes are stored in your vehicles computer. If you have a CAN scan (Controller Are Network) performed it will check all systems on your truck including the transmission. Here is a tutorial showing what is involved for a CAN scan:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Auto parts stores like AutoZone can perform free diagnostic scans for free if you don't have access to a scanner. Once you have this performed get back to us with any code numbers and we can then properly diagnose. Hope this helps and thanks for using 2CarPros.