Code
DF012
RENAULT
D
-> P0651 - Voltage Power; 2 sensors
Views:
UK: 7
EN: 13
RU: 10
AI status
Completed
Completed
100%
Causes
- Blown fuse or failed power relay for sensor supply
- Open or shorted wiring on the sensor power rail
- Poor or corroded connector pins at sensors or ECU
- Faulty sensors (internal short/open)
- ECU internal power driver failure or internal fuse
- Low battery voltage or poor battery/charging system
Symptoms
- MIL/Check Engine lamp illuminated
- Related sensors reporting implausible or no readings
- Driveability issues if sensors affect engine management (rough idle, hesitation)
- Intermittent faults that may clear when connectors are moved or vehicle restarted
What to check
- Retrieve freeze frame data and live sensor values with a scan tool
- Check battery voltage (should be ~12.4–12.8 V with ignition off, ~13.5–14.8 V with engine running)
- Inspect and test fuses and relays for the sensor supply circuit
- Visually inspect wiring and connectors for corrosion, damage, or water ingress
- Backprobe sensor power pins to measure supply voltage with ignition ON
- Check ground connections related to the sensor circuits and ECU
Signal parameters
- Expected sensor reference/ power rail: typically +5 V (verify with manufacturer data)
- Battery/ignition supply for sensors: ~12 V with ignition ON
- Ground: near 0 V (
- Open-circuit: infinite/very high resistance between sensor power pin and fuse/ECU
- Short to ground: near 0 V at sensor power pin
- Short to battery: near battery voltage present at sensor power pin when circuit should be switched
Diagnostic algorithm
- Read and record all stored codes and live data for the two affected sensors with a scan tool. Note freeze frame conditions.
- Verify battery and charging system voltages. Recharge/replace battery if voltage is low.
- Locate and check fuses/relays feeding the sensor power rail. Replace any blown fuses and retest.
- Visually inspect harness and connectors from the sensors to the ECU. Repair any damaged insulation, pins, or connector shells.
- Backprobe the sensor power pin(s) with ignition ON and compare to expected voltage (see signal_params). Wiggle harness and connectors to check for intermittent changes.
- Measure continuity/resistance between the sensor power pin and the fuse/ECU power output pin with ignition OFF. Look for high resistance or open circuit.
- Measure for shorts: disconnect sensors and measure resistance from the power rail to ground. Very low resistance indicates a shorted sensor or wiring.
- If wiring and fuses are good, swap or bench-test sensors if possible (or substitute known good sensors) to isolate a faulty sensor.
- If sensors and wiring check OK, suspect ECU power driver failure. Verify ECU supply voltages and grounds. Refer to manufacturer ECU test procedures before replacement.
- After repairs, clear codes and perform a road test and re-scan to verify the fault does not return.
Likely causes
- Damaged common power feed or wiring harness supplying the two sensors
- Loose/corroded connector at one of the sensors or the ECU
- Blown inline fuse feeding sensors
- ECU power output/driver fault when external wiring checks OK
Fault status
Status
Power/voltage fault detected on sensor supply circuit (affects two sensors). Check sensor power rail, fuses, wiring, connectors, and ECU supply.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email