Transmission or Electrical Problem?

Mo Power · #1 12-18-2007, 12:49 AM

Guys,

I was driving home from work when the transmission seemed to begin to slip. I then noticed that the engine was running very rough, so I decided to pull over. The service engine soon light was lit and the overdrive indicator on the shift lever began to flash. While waiting for the tow truck, I started the engine and gave it a little gas. The engine was missing very badly. Once the truck was towed to the dealer, I took my Hypertech programmer and found the diagnostic codes. I have not been under the hood monkeying around with anything. Like I said earlier, I changed the PCV valve about a month ago with a Motorcraft replacement PCV. Here are the trouble codes:

P0443 Evaporative Emission System Purge Control Valve Circuit
P1451 EVAP Control System Canister Vent Solenoid Circuit Malfunction
P0750 Shift Solenoid A malfunction
P0758 Shift Solenoid B Electrical
P1000 On-Board Diagnostic (OBD) Systems Readiness Test Not Complete
P0755 Shift Solenoid B Malfunction
P0743 Torque Converter Clutch Circuit Electrical
P0740 Torque Converter Clutch Circuit Mal****ion
P0753 Shift Solenoid A Electrical

It sounds like the wiring harness may be shorting out. What do you guys think???

Thanks for your help!

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LastSplash · #2 12-18-2007, 03:33 AM

Shorted out or unplugged, all of that stuff is located toward the back of the truck.

projectSHO89 · #3 12-18-2007, 08:45 AM

Check fuse F1.23

Steve

Mo Power · #4 12-19-2007, 01:02 AM

Everyone,

You will not believe what caused the issue! One of the O2 sensor wires rubbed against the drive shaft and shorted out. This also caused fuse 1.23 to blow which in turn threw the transmission codes and caused the truck to enter "Limp Mode". The dealer charged me $300 for the troubleshooting and for a new O2 sensor. It seemed kind of high, but I was very relieved it was just a sensor and nothing serious. That sucks that an O2 sensor can cause such havoc to a V8 engine!!!

Thanks to all of you who were very kind to offer advice! I told the service tech to search underneath the vehicle and I truly believe this helped the techs (even though they do not admit it)

projectSHO89 · #5 12-19-2007, 10:54 AM

Actually, I believe it perfectly since it's a common-enough problem. The O2 Sensor harnesses also tend to get onto exhaust components, melt, and cause the same problem.

You're lucky. On the earlier generation of vehicles, the fuse that blows will kill the entire engine due to loss of power for the computer.

Steve