P06E7

Code

Generic P — Powertrain

Sensor Power Supply C Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 51 RU: 24

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Causes

Short to ground in the Sensor Power Supply C wiring
Open or high-resistance supply (broken wire, corroded connector, poor pin contact)
Blown fuse or faulty power distribution connector
Failed sensor on circuit C drawing excessive current
Weak battery or poor main ground/charger output
Faulty ECU internal regulator or ECU hardware fault

Symptoms

Check Engine Light (MIL) illuminated
One or more related sensors reporting invalid values or dropping to zero
Intermittent faults or drivability issues if affected sensor is critical (misfires, rough idle, poor throttle response)
Engine may go into limp mode if ECU loses a required sensor reference
Stored low-voltage freeze-frame data or multiple related codes

What to check

Read freeze frame and all stored codes with a scan tool; note related sensor data and timestamps
Check battery voltage with engine off and key on (should be ~12.4–12.8V battery; ~13.5–14.8V charging with engine running)
Visually inspect harness, connectors, and pins for corrosion, broken wires, or pushed-out terminals at the affected sensor(s) and at ECU connector
Check relevant fuses and fusible links for continuity
Backprobe the sensor power/reference pin with key ON (engine OFF) and measure DC voltage vs battery negative
Inspect and verify good battery and engine ground connections

Signal parameters

Nominal sensor power/reference voltage (Circuit C): typically 5.0 V (varies by vehicle); acceptable approx. 4.5–5.5 V under no-load with key ON
If supply is low: measured voltage may be significantly below nominal (eg
Battery voltage reference: key ON (engine OFF) ≈ 12 V; engine running ≈ 13.5–14.8 V
Sensor supply current: normally small (mA); excessive current draw suggests short or failed sensor

Diagnostic algorithm

Safety first: secure vehicle, remove jewelry, and use insulated tools. Disable ignition when disconnecting connectors if required by manufacturer.
Retrieve and record freeze frame, pending and permanent codes and note which sensors are involved.
Visually inspect wiring, connectors, and fuses for the sensor power supply C circuit. Repair obvious damage/corrosion and re-test.
Verify battery and charging system voltages and clean/tighten battery and engine/chassis grounds.
With key ON (engine OFF), backprobe the sensor power/reference conductor for Circuit C and measure voltage to battery negative. Compare to expected nominal (usually ~5 V).
If voltage is low, remove the connector at the sensor and re-measure at the harness side. If voltage rises to nominal with sensor disconnected, suspect the sensor is shorted/failed. If still low, suspect wiring short to ground, blown fuse, or ECU regulator problem.
Check fuses and fusible links in the sensor power distribution and repair/replace as needed.
If harness-side voltage is low, check for continuity to ground from the power lead to locate a short. Use an ammeter to measure current draw in the feed to help locate a shorted branch.
If wiring and fuses are good and no load is found when sensors are disconnected, suspect internal ECU power regulator failure. Follow manufacturer procedure for ECU bench testing or replacement; consult wiring diagrams and service information before replacing the ECU.
After repairs, clear codes and road-test to confirm fault does not return. Re-scan and monitor live data for stability.