How to check Pin 13 for 18v on SCP/FEPS vehicles.
The SCP(Comms) network setup has a Flash EEPROM Programming Signal (FEPS), which is pin 13 on the OBD-II port. It's nothing more than an 18-volt signal to the powertrain control module (PCM) to allow the module to accept the new programming.
Step1: Locate the vehicles OBDII port. Most can be found under the driver side dash within a couple feet of the steering column.
Step2: Remove the OBDII Port from the stock location. You’ll need access to the back of the pins. Most are held in place by 2 screws or clips.
Step3: Check Pin16 for voltage. Pin16 is battery power and should have 12v. Set the Multimeter to read voltage. Position the multimeter leads on Pin16(Pwr) and Pin4(Grd).
Step4: Check Pin13 for Voltage. Pin13 is the FEPS signal and should have 18v while unlocking/flashing the vehicle. Position the multimeter leads on Pin13(FEPS) and Pin4(Grd). Go through the programming process and check if voltage goes from 12 to 18 voltage.
