Ford P06A8 code — The Most Common Cause

A damaged wire is the most common cause of a Ford P06A8 code and P0222, P0322

P06A8 indicates a problem with the sensor reference voltage

Ford throttle position sensor

“C” circuit. It means the Powertrain Control Module (PCM) has detected an issue with the voltage signal or performance of a specific sensor.A Ford P06A8 trouble code (defined below) is often accompanied by low power, no throttle response, or a no-start condition, along with trouble codes P0222, and P0322.

P06A8 – Sensor Reference Voltage C Circuit Range/Performance
P0222 – Throttle/Pedal Position Sensor/Switch B Circuit Low
P0322 – Ignition/Distributor Engine Speed Input Circuit No Signal

In this case, the P06A8 is most likely the root cause because it depicts a situation where the throttle position sensor and ignition sensor are not seeing the 5-volt reference voltage from the PCM.

Most common cause of a Ford P06A8 code

A P06A8 can be caused by a short to ground on the reference voltage on any of the sensors in the circuit. One way to test is to get a wiring diagram, locate each of the sensors on the circuit and unplug one at a time to see if the 5-volt reference returns.

However, before you do that, shops are reporting a Ford Focus issue where a sharp edge on the throttle body tends to cut the reference voltage wire, damaging the harness. So that should be your first check.

Locate the main harness near the throttle body and check for signs of cuts/chaffing. Repair as needed. Then clear the trouble codes and drive the vehicle to see if they come back.

Other possible causes of a Ford P06A8 code

Failed Sensor: The sensor itself may have malfunctioned, causing inaccurate readings and triggering the code.
Wiring Issues: Damaged, corroded, or loose wiring in the sensor circuit can disrupt the voltage signal.
Ground Fault: A short to ground in the circuit can also cause this code.
PCM Problem: In rare cases, the problem may lie within the PCM itself.

©, 2022 Rick Muscoplat