What Does P06B0 Mean?
The 5-volt sensor power supply circuit "A" from the PCM is open or not providing the correct reference voltage to the sensors it feeds. This circuit typically powers multiple engine sensors such as the throttle position sensor, MAP sensor, and fuel pressure sensor. The driver may notice poor engine performance, rough idle, stalling, or multiple sensor-related DTCs setting simultaneously.
Safety Warning
Loss of the 5V reference affects multiple engine sensors simultaneously, causing severe drivability problems including possible stalling. The vehicle should not be driven until repaired, as the engine may stall without warning in traffic.
Common Causes
35%
Shorted sensor on the 5V reference A circuit dragging the voltage down and causing an open-circuit protection response
25%
Wiring harness damage — chafed, shorted, or broken wire on the 5V reference A circuit
20%
PCM internal 5V reference regulator failure on the A circuit
15%
Corroded or damaged connector pins at the PCM or at a sensor creating high resistance or open circuit
5%
Aftermarket sensor or accessory installed on the reference circuit causing overload
Diagnostic Steps
1
Measure the 5V reference voltage at multiple sensors on the A circuit (TPS, MAP, etc.) — if all read 0V or near 0V, the fault is upstream at the PCM or in the common supply wire.
2
Disconnect sensors one at a time on the 5V reference A circuit while monitoring the voltage — if voltage returns when a specific sensor is unplugged, that sensor has an internal short.
3
Inspect the wiring harness from the PCM to each sensor on the A circuit for chafing, bare wires, or shorts to ground — pay special attention near the exhaust manifold and sharp body edges.
4
Check all connector pins on the 5V reference A circuit for corrosion, spread terminals, or water intrusion.
5
If all external wiring and sensors test good, the PCM internal 5V regulator has likely failed — confirm by backprobing the PCM connector for 5V output with sensors disconnected.
Estimated Repair Cost
$75 - $1,200
Parts + labor, varies by vehicle and location
The 5-volt sensor power supply circuit "A" from the PCM is open or not providing the correct reference voltage to the sensors it feeds. This circuit typically powers multiple engine sensors such as the throttle position sensor, MAP sensor, and fuel pressure sensor. The driver may notice poor engine ...
The most common cause of P06B0 (Sensor Power Supply "A" Circuit/Open) is: Shorted sensor on the 5V reference A circuit dragging the voltage down and causing an open-circuit protection response
Typical repair costs for P06B0 range from $75 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Loss of the 5V reference affects multiple engine sensors simultaneously, causing severe drivability problems including possible stalling. The vehicle should not be driven until repaired, as the engine may stall without warning in traffic.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P06B0 to identify the root cause.
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Quick Info
Category
Powertrain
System
Sensor Reference Voltage / Engine Control
Difficulty
Type
Generic (SAE)
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