P0652
PPowertrainSensor Reference Voltage B Circuit Low
What does this code mean?
Severity : HighP0652 indicates low voltage on sensor reference circuit B, the regulated supply, often 5 V, that the engine control module provides to several sensors. When this reference drops, every sensor that relies on it reports false values. Which sensors share circuit B varies by manufacturer.
Symptoms
- Check engine light on.
- Several sensor codes stored at the same time.
- Limp mode or loss of power.
- Possible hard starting or stalling.
Possible causes
- A sensor with an internal short pulling the reference to ground.
- Sensor supply wiring shorted to ground.
- Damaged or water contaminated connector.
- Internal engine control module fault.
Diagnosis and repair
- Use the wiring diagram to identify the sensors on reference B.
- Measure the reference voltage with a multimeter, key on.
- Unplug sensors one at a time to see if the voltage recovers.
- Inspect the harness for crushed or bare wires.
- Replace the sensor or repair the wiring, clear the codes and road test.
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Code
P0652
Category
Powertrain
Prefix
P
Standard
OBD-II / SAE J2012