P06E8

Code

Generic P — Powertrain

Sensor Power Supply C Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 25 EN: 37 RU: 32

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Page language: EN

Causes

Short to battery voltage (VBatt) on Sensor Power Supply C wiring
Damaged or corroded sensor connector or pin causing improper voltage
Aftermarket accessory tapping into sensor reference circuit
Poor or missing ground on related circuits changing reference behavior
Internal ECU/PCM power supply or driver failure
Incorrectly installed replacement sensor or harness

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Related sensors reporting implausible/high values or going to fixed limp values
Driveability issues (stalling, poor idle, hesitation) if affected sensor is critical
Intermittent faults if wiring harness is damaged

What to check

Read freeze frame and live data to identify which sensor(s) use Sensor Power Supply C
Check key‑on engine‑off (KOEO) and key‑on engine‑running (KOER) reference voltage at the sensor connector (expected ~5.0 V; consult vehicle spec)
Measure battery voltage to compare against reference voltage
Visually inspect wiring, connectors, and harness for damage, pin corrosion, or evidence of aftermarket splices
Disconnect the suspected sensor(s) and observe whether the high-voltage DTC clears or changes
Perform a backprobe continuity and short-to-B+ test between reference circuit and battery positive

Signal parameters

Expected sensor reference voltage: ~4.8–5.2 V (vehicle-specific)
High condition: measured voltage significantly above spec (>~5.5 V) or near battery voltage (~12 V)
Open/low condition: measured significantly below spec (
Normal battery voltage: ~12–14.5 V

Diagnostic algorithm

Retrieve codes and freeze frame. Identify which sensor(s) use the Sensor Power Supply C reference.
With key ON engine OFF, measure voltage at the suspect sensor reference pin. Compare to manufacturer spec (typically ~5 V).
If voltage is high, inspect harness between sensor and ECU for a short to battery (backprobe and use an ohmmeter to check continuity to B+ with power removed).
Disconnect the sensor connector. If the voltage drops to normal at the ECU pin with the sensor disconnected, suspect the sensor or an accessory on that branch.
Visually and mechanically inspect connectors and pins at the sensor and ECU for corrosion, bent pins, or exposed conductors. Repair as needed.
Check for aftermarket devices or previous repairs tapping into the reference circuit; remove or reposition taps.
Wiggle test harness while monitoring reference voltage and DTC occurrence to find intermittent faults.
If wiring and connectors check good, perform resistance and short tests from the ECU reference pin to battery positive and to ground. If short to B+ is present at ECU pins, repair or replace wiring or ECU as appropriate.
If suspect ECU internal fault (no external short found), consult manufacturer service information; consider ECU replacement only after wiring harness and sensors are confirmed good.
Clear codes and road test to confirm repair. Re-scan to ensure no return of the code.

Likely causes

Wiring short to B+ on the sensor reference (most likely)
Connector corrosion or bent pin at the sensor or ECU
Accessory or repair wiring incorrectly connected to the 5V reference
ECU internal fault (less common if wiring checks good)

Fault status

⚠️ Status

Sensor Power Supply C Circuit High — reference voltage on Sensor Power Supply C is above the allowable threshold, indicating a possible short to battery, wiring/connector fault, or ECU power-supply issue.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3.0 hours