The engine module feeds sensors from several regulated 5 V reference circuits; a short at one sensor pulls the whole circuit down and all its sensors report at once – unplug them one by one to find the culprit. P06A8 is the range/performance check of reference circuit C, without separate low and high codes. Ford uses it: its 2012 and 2020–23 petrol tables flag below 4.7 V or above 5.2 V for 0.5 s (Bosch modules), the 2023 diesel supply 3 below 4.7 V or above 5.3 V; in Ford's DPS6 transmission module it monitors the output speed sensor supply. GM uses the collective code P0697 for circuit C instead.
Medium severity. Can I keep driving?It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.
Symptoms
- Check engine light
- Several sensor codes at once
- Reduced power or limp mode
- Possibly starting problems
Most likely causes
- Short in the wire or sensor of a connected sensor
- Chafing or water in harness or connector
- A connected sensor faulty internally
- Module internal voltage regulator or components
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P06A8 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 6: Control modules and outputs
- A8: Specific fault in that system
Frequently asked questions
Can I keep driving with code P06A8?
It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.
What causes code P06A8?
The most common causes are: short in the wire or sensor of a connected sensor; chafing or water in harness or connector; a connected sensor faulty internally.
Related codes
- P06A6Sensor Reference Voltage A Circuit Range/Performance
- P06A7Sensor Reference Voltage B Circuit Range/Performance
- P06A9Sensor Reference Voltage D Circuit Range/Performance
- P0697Sensor Reference Voltage C Circuit/Open
- P0698Sensor Reference Voltage C Circuit Low
- P0699Sensor Reference Voltage C Circuit High
- P0720Output Shaft Speed Sensor Circuit
Sources
- law.cornell.edu: 13 CCR 1968.2
- newtonnet.co.uk: fordobd2012
- fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
- fordservicecontent.com: obd summary diesel 2023
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.