No third gear

Good morning,

Yes, the TCM should be re-flashed with the current programming.

You can either take it to a shop that can perform this or to the dealer who will be the highest price.

Roy

Got a shift solenoid code replaced it and it bangs in third and goes slow. what could be the issue?

What was the code number?

Roy

P0748 and p0750.

Got it.

These codes are electrical codes related to the wiring harness inside the transmission.

You need a scan tool that can monitor the actions of the solenoids and switches.

Roy

After i replaced shift solenoids and had the codes read again turns out now all i have is a speed sensor code. thank you for all the help. hope this is all.

You are welcome.

Roy

Replaced speed sensor from Ford i am going 60 mph at 4,100 rpm's. Help don't think drive is working still a big thorn in my backside.

Can I have the code number?

Roy

P0720. pretty sure this new speed sensor is toast.

This code is not a component issue. It is a wiring harness issue.

You will need an advanced scan tool to access the transmission and check the voltages for the output speed sensor. This is not an easy one to fix.

Roy

P0720
Descriptor
Probable Causes
Output Shaft Speed (OSS) Sensor Circuit Open
Output Shaft Speed (OSS) Sensor Circuit Shorted to Ground
Output Shaft Speed (OSS) Sensor Circuit Shorted to Power
Output Shaft Speed (OSS) Sensor Damaged

Scan tool showed no signal. already probed the plugs with ohms meter today. both were fine the speed sensor was reading over 234 ohms.

The sensor generates its own voltage. You need to see if that signal is getting to the modules. My guess is that it is not.

Roy

How can i find out that information?

Sorry, we do not do phone calls.

Roy

That is fine. it is getting power to speed sensor. i called Ford and they ordered another one it is just two weeks of aggravation and missed work.

If it is not getting to the modules how can i fix this problem? i work 45 minutes from home. i am going to attempt to get there tomorrow. do you think I will cause more damage driving it at 50 mph?

Again, as I stated, This is a wiring issue, not a sensor issue. The possibilities listed all indicate a wiring issue between the sensor and the ECM.

You can try another sensor but I bet you have the same issue.

Roy

Hello again Roy, i looked at all the wiring did a ground drain test also got some interesting feed back i disconnected my brand new alternator and the car shifted well for a little while until the battery was going low. this is a robot car i guess one problem to the next.

Do you have a scan tool that can read live transmission data?

Roy

No Roy. i wish i did have an obd2 scanner.

At this point, you need to have someone look at it and see the live data around the sensor to see if it is getting the proper commands.

Roy

Thank you for all your help. i am done chasing wires and grounds etc. your help has been greatly appreciated.

You are welcome.

Always glad to help.

Roy

Well rebuilt the entire transmission still no third. everything was toast, the converter went. it even broke the bell housing. so after i was finished it leaked like crazy. are my shift solenoid's bad?

Okay, did you air test each clutch pack before you completed assembly to be sure the piston and seals were good?

Is the check engine light on? If it were a solenoid, it would set a code.

Roy

Hi Roy, no i didn't air test anything but this would be the second transmission doing the same thing; no third gear. i have tested speed sensor wires all good, but still no signal from speed sensor.

Okay, how do you know there is no signal from the speed sensor?

You could have a cracked piston in the third gear clutch. That's why I asked about the air test.

Did you replace all clutches and seals in the transmission?

Roy

Well, figured out my transmission issue. be careful the two sensor wires are the same for speed sensor. switched them it shifts perfect. thanks for all the help. i will never rebuild a cd4e again. lol