P06D3

What it means

P06D3 is a generic code meaning the powertrain control module has detected that sensor reference voltage circuit 'E' is lower than expected. The reference supply (normally about 5 volts) feeds a group of sensors, and the module saw it sag or sit near zero. Which sensors share circuit E depends on the make, model and engine, so the wiring diagram is needed to confirm this.

Symptoms

• Engine warning light on
• Poor running, hesitation or reduced power
• Limp mode or restricted throttle response
• Rough idle or stalling
• Difficulty starting or no start
• Other sensor fault codes stored at the same time

Possible causes

• Short to earth in the wiring of the shared 5 volt reference circuitlikely
• A faulty sensor on circuit E pulling the reference voltage down internallylikely
• Damaged, corroded or water-affected connector or terminals on the reference circuitpossible
• Chafed or pinched harness touching bodywork or enginepossible
• Poor power or earth supply to the control module affecting its internal regulatorpossible
• Internal fault in the powertrain control module reference voltage supplyrare

How to diagnose

1. Read all stored and pending codes and record the freeze frame data; note any other sensor circuit codes, as shared supply faults often set several together.
2. Use the wiring diagram to identify which sensors are on reference circuit E for this vehicle.
3. Inspect the harness and connectors for the listed sensors for chafing, water ingress, corrosion, bent or pushed-back pins.
4. With the ignition on, measure the reference voltage at the sensor connector and compare it with the specified value.
5. Unplug the sensors on circuit E one at a time and watch whether the reference voltage recovers; the sensor that restores it is the likely culprit.
6. With the module and sensor disconnected, test the reference wire for a short to earth and for resistance to other circuits.
7. Check the module's power and earth supplies and voltage drop under load.
8. If wiring and sensors are all proven good, check for relevant technical service information before considering the control module.

How to fix

• Repair or replace any wiring shorted to earth, restoring correct insulation and routing.
• Replace the sensor that is dragging down the reference voltage.
• Clean or replace damaged connectors and terminals, and dry out any water ingress.
• Repair poor power or earth connections to the control module.
• Replace or repair the control module only after all other causes are ruled out, following the manufacturer's procedure.

Can I keep driving?

Nearby codes

• P06D2GenericSensor Reference Voltage E Circuit/Open
• P06D4GenericSensor Reference Voltage E Circuit High