P06A5: Sensor Reference Voltage D Circuit High

The engine module feeds sensors from several regulated 5 V reference circuits; a short at one sensor pulls the whole circuit down, so all its sensors report at once – unplug them one by one to find the culprit. On GM engines (2016–2025) circuit D feeds pedal sensor 1 and both throttle position sensors, on the Saab 9-4X the throttle and pedal sensor 1 – a fault therefore usually means electronic throttle limp mode. P06A5 means reference D is too high – a short to voltage, for example via a sensor signal wire. No manufacturer document available to us uses P06A5 itself: GM and Saab report circuit D faults collectively as P06A3. The description follows circuits A–C.

Symptoms

• Check engine light
• Several sensor codes at once (pedal, throttle, pressure)
• Electronic throttle limp mode, reduced power
• Possibly starting problems

Most likely causes

• Reference or sensor signal wire shorted to 12 V
• Chafing or water in harness or connector
• A connected sensor faulty internally
• Module internal voltage regulator

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the battery and grounds
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Clear the code and see if it returns
4. If it is a reference voltage code, disconnect sensors one at a time and see if the voltage recovers
5. Check whether a software update is available
6. Do not replace the control module without a full diagnosis

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P06A5 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 6: Control modules and outputs
• A5: Specific fault in that system

Frequently asked questions

Can I keep driving with code P06A5?

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 P06A5?

The most common causes are: reference or sensor signal wire shorted to 12 V; chafing or water in harness or connector; a connected sensor faulty internally.

Related codes

• P06A3Sensor Reference Voltage D Circuit/Open
• P06A4Sensor Reference Voltage D Circuit Low
• P0699Sensor Reference Voltage C Circuit High
• P0643Sensor Reference Voltage A Circuit High
• P2123Throttle/Pedal Position Sensor/Switch D Circuit High

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
• saabwisonline.com: p06a3 00

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.