Pedal Potentiometer

[Jgkram]

Took the car for a drive and the darn thing went into limp mode. Read the codes and they were P1219, P1577 and P1578. All associates with the pedal and both pedal potentiometers. I pulled the sensor and ohm’d the pots. Pot 1: Gn-Gr = 1.76, Gn-Yw = 1.23 and Gr-Yw = 2.72, Pot 2: Brn-Pnk = 1.27, Brn-Wht = 2.12 and Pnk-Wht = 1.24. I can’t find a source that tells me what the resistances should be. Anyone know? Thanks

[Paul]

You need to check the resistance between each of the 6 pins in the sensor plug to the corresponding pins on plug IV of the DME. What year is your car?

The system works by comparing pot 1 to pot 2. One runs at 1/2 the voltage of the other. Any compromise in the wiring and connections between the sensor and DME can throw off the ratio and cause the limp mode.

[Jgkram]

Thanks Paul. I have a 2001 base. Just so I understand, regardless of the value of the resistance I see, there should be roughly 1/2 values between pot 1 & 2, correct? How much difference between the two can the DME tolerate? 1%, 5%, 10% what is the norm for these things? Again, thanks for the comments.

[78F350]

This diagram shows the wiring from the potentiometer to the DME. I didn't find anything in the manual that had direct troubleshooting for the pedal.

[78F350]

This one has been sitting in a box since I stripped an '01 in 2015. $40 shipped sound good?

[Paul]

Not really sure how much the values can be out of range. This car had an intermittent issue which was finally resolved by replacing a corroded pin on DME plug IV.(7.8 DME) It caused a problem usually when the humidity was high.

As you can see from the pictures at the time I was troubleshooting this, the throttle angles were the same for both pots even though the voltages were not 1 and 1/2. I have not seen a sensor failure yet. This owner had already replaced his sensor to no avail.

[Paul]

Here's a hard failure that caused a limp home...