Hello Guys, I'm new and I'm breaking the unspoken rule of asking for help before giving any but I'm hoping that with your help I will be providing help to someone in the future with getting this solved. Ok, So for 2 Months now i have been trolling every forum and bought a Haynes Manual but cant figure it out. I have a 2008 Mustang GT and I did the transmission swap from Auto to Manual (Yes i know you all hate it and i should never do it but its done so stick to the problem at hand) EVERYTHING went great but one thing. (Note: i reused the Auto PCM and Auto Wire Harness and got a new tune with my bama tuner) My Speedometer does not work and I'm in Limp Mode with Code P061C. Now your first guess of bad speed sensor, already tested and replaced, both passed. Did a continuity test from the sensor to PCM and it was good, went as far to jack up the car, put it in gear and check for A/C Volts at the PCM. I looked up wiring diagrams for it but the best i could find was what ever one uses and it says 05 to 07 and i checked all the pin outs and they are correct (but could they have changed it mid 08?). I thought maybe the ABS speed sensor my play a part in giving information for speed like so cars but research says no and i have no ABS lights or TCS Lights on. I Checked for Ground, PCM works fine becasue they is nothing else wrong wit the car it runs fine just wont rev over 4k RPMs. I'm at a Complete lose and I'm hoping I over looked something because its a 08 and i followed the forum by Anothy05GT for his 05. So your mission if you choose to accept it is to help figure this out so the next time it happens they can troll my post and get the info they need!

 

PCM is looking for other signals that only exist with an Automatic, you need a new Ford program strategy that is expecting a manual transmission and/or to replace the harness so that the wiring is setup for the manual trans as well. If you simply left the existing PCM there and changed the hardware (Transmission) without changing the software (PCM strategy) that's the problem. The tune from Bama is for an automatic since they tuned it for the Strategy code you gave them.

 

No I'm sorry I didn't say this but i had Bama update my tune to a manual, they actually did it 3 times and i data logged for them and they said it was a mechanical problem and not tune related which i do not believe because i test the speed sensor and it worked and i read A/C Volts from the pins at the PCM. Also i checked the Cam sensor just in case. I know the speedo works because it moves at start up and the doors don't lock because the car does think its moving. there is only two wires that make this work so idk whats going on,

 

https://www.obd-codes.com/p061c

"Engine RPM is monitored (by the PCM and other controllers) using input signals from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor/s. Desired engine RPM is programmed into the PCM and other controllers. Actual RPM is calculated using input data from the CKP and CMP sensors, as well as the throttle position sensor (TPS), and other engine and transmission sensors. Desired RPM is then compared with actual RPM.


Copyright OBD-Codes.com"

You can try another tune vendor but to me, that sounds like a wiring issue or PCM misread issue. Speedo powering up (movement) does not translate to working correctly. It just means it sees power.

 

OK so if i understand that right, if my CKP or CMP are bad it could cause limp mode and no speedo? if they where bad wouldn't my car not run? I Know i dont have a code for them, what would be the best way to check them to know they are good??

 

In theory yes but you would get codes those were bad.

In reality, I would check your wire harnesses for pinched or broken wires first. Especially those going into the PC and near/around the transmission. (behind the intake manifold where that big engine harness. Then check all the connectors you touched for broken or bent pins.

 

so i checked the cam and crank sensor and they are all good.

 

So Update..... I Got the car to work! Solution was to install an Manual PCM (I Used the Auto wire harness after do the steps needs to work as an manual) and i installed a simple jumper wire on the pins under the dash where the clutch wiring harness goes (couldn't find one) Note....YOU CAN reuse the auto PCM to manual on 05 and 06 ONLY! 07 to 10 need to use a Manual PCM with PATS turn off and a Jumper wire or clutch wiring harness. Also only 07 and 08 can be swapped around the same for 09 and 10. but you cant do 09 and 08 or anything. i hope this helps someone, if you need any info please email me.

 

Glad to read you got it figured out. Thanks for posting the solution back! What drove you to that conclusion?

 

i have an 06 and im having the same problems.speedo dont work ,reverse lights stay on,limp mode and code po61c.i have the bama tune.thought i messed the pcm up some how.tried reflashing tune with no luck so i put the auto tune back on and speedo works (just doesnt read correctly since its running from a manual ),reverse lights stayed off and no more po61c..of course im getting every code possible for a missing auto.and will get a wrench if i dont turn off the traction control.