This was the first time I have ever seen 12v on a potentiometer style throttle position sensor. The spec for this sensor is around .5v at idle at around 4v at wide open throttle and this Jeep was fixed at 12v all the time. Scan data was misleading as the TPS data parameter showed a constant 5v regardless of throttle angle. Also when performing signal circuit integrity type testing, you will now understand why we use a resistor instead of a jumper wire.

In this video I’ll show you how to retrieve trouble codes from an OBD-I vehicle, a 1991 Eagle Talon (which is a Mitsubishi Eclipse), and how to test a throttle position sensor with a graphing multimeter.