P06B0

Code

Generic P — Powertrain

Sensor Power Supply A Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 29 EN: 44 RU: 33

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Page language: EN

Causes

Open or broken wiring in the sensor power/reference circuit
Corroded, loose or damaged connector at the sensor or harness
Blown fuse or fusible link supplying the ECM reference circuit
Short or open inside the sensor (internal failure)
Faulty ECM / internal power driver failure
Aftermarket equipment or repair damage to wiring harness

Symptoms

Check Engine Light (MIL) illumination
Related sensor(s) reporting implausible or no readings
Engine may run poorly, rough idle or reduced performance if critical sensor(s) affected
Intermittent driveability issues if connection is intermittent
Possible limp-home mode if ECM disables systems that rely on the sensor

What to check

Scan for stored and pending codes and note freeze-frame data
Visually inspect related sensor connector(s) and wiring for damage, corrosion, pin push-out
Backprobe sensor connector with ignition ON and measure reference voltage
Measure reference voltage at the ECM pin and compare to sensor pin
Check continuity between ECM reference pin and sensor connector pin
Check relevant fuses and power supplies feeding the ECM reference circuits

Signal parameters

Expected sensor reference voltage: approximately 5.0 V (typically 4.8–5.2 V) with ignition ON, engine OFF
With circuit open: sensor-side reference voltage will be 0 V or floating; ECM pin may show 0 V or abnormal reading
Continuity: low resistance between ECM reference pin and sensor connector pin (usually
Current: sensor reference supply provides low current to sensors (mA range); large current draw indicates short to power/ground

Diagnostic algorithm

Retrieve freeze-frame and live data with a scan tool; note which sensor(s) use the Sensor Power Supply A reference.
Visually inspect connectors, pins and harness from the affected sensor(s) to the ECM for damage, corrosion or repairs.
With ignition ON (engine OFF), backprobe the sensor reference pin and measure voltage. Expected ~5 V. If correct at sensor, suspect sensor or signal return.
Measure voltage at the ECM reference pin. If ECM pin shows ~5 V but sensor pin is 0 V, perform continuity check between ECM pin and sensor connector.
If continuity is open, trace and repair the wiring (repair harness, replace connector, remove corrosion).
If wiring continuity is good but sensor pin still low, disconnect the sensor and measure resistance to ground to check for short to ground in the harness or sensor.
Check related fuses, relays, and main power feeds that supply the ECM reference; replace any blown fuses.
If wiring and sensor test good, consider replacing the sensor. If problem persists, suspect ECM internal 5V reference driver—verify with manufacturer procedures before replacing ECM.
After repair, clear codes and road test to confirm the code does not return. Re-scan for pending or permanent codes.

Likely causes

Connector pins pushed out, corroded, or bent at sensor or ECM
Broken wire due to chafing, heat, or abrasion near engine or frame
Blown 5V reference fuse or open supply from main power rail
Sensor harness disconnected after recent work
ECM output (5V reference driver) failed (less common)

Fault status

⚠️ Status

ECM detected an open or interrupted Sensor Power Supply A circuit. Fault stored in memory and MIL may be illuminated. Freeze-frame data and live PIDs may show the affected sensor(s) are not reporting or showing implausible values. May set related systems to default/limp behavior.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3 hours