C2 - Check VREF Voltage
- Key "ON", engine "OFF".
- Breakout box installed, Powertrain Control Module (PCM) connected.
- Measure voltage between test pin 26 and test pin 46 at the breakout box.
- What is the voltage?
Greater than 6.0 volts: Go to C4. C4 - Check For Excess Voltage On VREF Circuit
Less than 4.0 volts: Go to C5. C5 - Check For Shorted Throttle Position Sensor
Between 4.0 and 6.0 volts: Go to C3. C3 - Check VREF and SIG RTN Circuits For Continuity