Getting Code 31c and 31o..What to check.

[two_stangs]

I am getting code:

31c
31o

On my code reader. It means the EVP or PFE Circuit is below minimum voltage.

EVP : EGR Valve Position Sensor or its Circuit
PFE : Pressure Feedback EGR Sensor or its Circuit

I replaced the EGR Sensor and the EGR Valve. So it must be in the circuit. Where does the circuit lead to? What Harness? I've tried to follow it but I loose it in all the wiring behind the intake manifold.

Does anyone know the Cause or Fix?

 

[two_stangs]

I guess no deals right now. I will have to give people time to answer.

I'm so sick of fixing my 89 GT convertible. As soon as I get it smogged I'm selling it.

 

[jrichker]

CODE: 31 (KOEO) - EVP circuit below minimum voltage. Vref (5 volt reference voltage supplied by the computer) missing or broken wire or bad contact in circuit. Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or MAP sensor located on the firewall near the center of the car. With the sensor removed from the EGR and still connected, press the plunger and watch the voltage change on the brown/lt green wire. Check for the same results on pin 27 on the computer.

 

[two_stangs]

Thanks. I will do that tomorrow morning.