Hi I'm having a shifting issue with my Mustang. It is a 99 gt automatic. I take it down the road and it won't shift. But if I floor it it'll shift around 4-5,000 rpms. Fluid is fine and where it should be. It's the color it should be. Nothing seems burnt or anything. Just really stumped.
Does using the shifter make any difference? I will look for my Factory Shop Manual Troubleshooting section when I get a chance. Tried Googling but nothing pertinent seemed to come up.
I would definitely appreciate that. Did have check engine light come on so I read my trouble codes and it came up as a throttle position sensor fault. Would the TPS cause shifting issues?
The TPS is a potentiometer type of electrical component. Rather than just being opened or closed like a switch, it controls the circuit by varying its resistance in response to throttle position.
In most cases this variable resistor will send a very low voltage back to the main computer when the throttle plates are fully closed. This reference voltage rises as the throttle opens to increase speed.
Keep in mind that some manufacturers use inverse voltage readings for feedback. A bad part can cause many problems in overall performance. Inaccurate data can cause transmission problems as well. Some transmission problems can be related to TPS sensor malfunction.
As an example, no up shifting, fast up shifts, late or delayed shifts, and line pressure problems that control internal solenoids and torque converter clutch engagement. Engine related problems can include a tip in or hesitation when cracking the throttle. Throttle position sensor
The Throttle Position sensor measures the throttle position, which is controlled by the gas pedal. It is used to determine engine load and if it fails it can cause automatic transmission shifting problems. It is used by the vehicle's computer to control engine performance by increasing the amount of fuel delivered as the throttle opens. In theory, the throttle position sensor is not necessary for proper engine operation because the mass airflow sensor and the manifold absolute pressure sensors can be used to determine the amount of air traveling into and engine at any point in time. However, the throttle position sensor is beneficial for proper automatic transmission control because it immediately establishes the driver's intent, and transfers this information to the transmission control module.
Still looking for my manual but.....this sounds like it might be the problem. Easy and cheap to fix!