Sensor Reference Voltage Circuit Low
The P0652 code indicates that the Engine Control Module (ECM) has detected a low voltage condition on the 5-volt reference circuit that powers various sensors (e.g., throttle position, crankshaft position, manifold absolute pressure). This can be caused by a short to ground, a faulty sensor, or a damaged wiring harness. The ECM monitors this voltage and triggers the code when it falls below a specified threshold, often leading to multiple sensor malfunctions and drivability issues.
01. Most Common Causes
- Short to ground in the 5-volt reference circuit
- Faulty sensor (e.g., throttle position sensor, MAP sensor)
- Damaged wiring or connectors
- Failed ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine stalling or rough idle
- Poor acceleration or hesitation
- Multiple sensor-related codes present
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0652 and check for other codes.
Step 2: Visually inspect wiring and connectors for damage, corrosion, or shorts.
Step 3: Measure voltage at the 5-volt reference circuit with a multimeter; should be around 5 volts.
Step 4: Disconnect sensors one by one to isolate the short; if voltage returns to normal, the last disconnected sensor is likely faulty.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause stalling, poor performance, and potential damage to the ECM or sensors.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, but can be higher if the ECM needs replacement.