P06A5

What it means

P06A5 is a generic code meaning the powertrain control module has detected a high voltage in the circuit for sensor reference voltage D. This is one of the regulated supplies (often 5 volts) the module provides to a group of sensors. The module saw the supply voltage above its expected upper limit, or the supply shorted to a higher voltage, so it set the code. Which sensors share reference D depends on the vehicle, so check the wiring diagram for the specific model and engine.

Symptoms

• Malfunction indicator lamp on
• Engine running roughly, hesitating or lacking power
• Limp mode or reduced power
• Erratic or implausible readings from sensors on the shared supply
• Poor starting or stalling in some cases
• Other sensor circuit codes stored alongside it

Possible causes

• Reference supply wire shorted to a higher voltage source, such as a battery feed, in the harnesslikely
• Damaged, chafed or corroded wiring or connectors on the shared sensor supply circuitlikely
• Internal fault in one of the sensors on the shared supply pulling the voltage uppossible
• Water ingress or contamination in a connector or junction causing a short between circuitspossible
• Poor or open sensor ground causing the reference voltage to read highpossible
• Fault inside the powertrain control module regulating the supplyrare
• Previous poorly done wiring repair or aftermarket accessory wiring tapped into the circuitrare

How to diagnose

1. Read all stored codes and freeze frame data, noting any other sensor or reference voltage codes that point to the shared circuit
2. Look up the wiring diagram to identify which sensors share reference voltage D on this model and engine
3. Visually inspect the harness and connectors for chafing, corrosion, water, bent pins and signs of previous repairs
4. Check live data for the affected sensors to see which read at the extreme high end or are implausible
5. Unplug the sensors on the shared supply one at a time and see whether the reference voltage returns to normal
6. With the ignition on, measure the reference supply voltage at the sensor connector and compare it with the specification
7. Check the circuit for a short to a higher voltage and test the sensor grounds for resistance with the module disconnected, following the wiring diagram
8. If the wiring and sensors all prove good, check for software updates and have the control module tested before replacing it

How to fix

• Repair or replace the damaged wiring section or connector that is shorting to a higher voltage
• Clean, dry and re-secure corroded or wet connectors, replacing terminals that are damaged
• Replace the faulty sensor that is pulling the reference supply high
• Restore or repair poor sensor ground connections
• Remove or correct any faulty aftermarket wiring connected to the circuit
• Repair or replace the control module only after all wiring and sensors are proven good, and follow the manufacturer's programming procedure

Can I keep driving?

Nearby codes

• P06A4GenericSensor Reference Voltage D Circuit Low
• P06A6GenericSensor Reference Voltage A Circuit Range/Performance