P34B3

Code

Generic P — Powertrain

A Camshaft Position Actuator Position Sensor A Circuit High Bank 2

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 23 RU: 18

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Page language: EN

Causes

Open, short or high-resistance wiring in the sensor signal, reference, or ground circuit
Corroded, loose or damaged connector at the sensor or ECM
Failed camshaft position actuator position sensor (Bank 2, Sensor A)
Short to battery voltage on the sensor signal wire
Faulty ECM (rare)
Mechanical fault in VVT actuator causing sensor to read out-of-range

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
Rough idle, reduced power or poor drivability under some conditions
Possible engine limp-home mode or reduced performance
Erratic camshaft timing behavior or noise from VVT area (less common)

What to check

Read and record freeze-frame and live data for camshaft actuator position A (bank 2) using a scanner
Visually inspect wiring and connector for damage, corrosion, or loose pins at the sensor and ECM
Check related fuses and power supplies
Backprobe sensor connector and measure signal voltage at key engine positions and during cranking
Verify reference voltage (typically ~5 V) and good ground at the sensor connector
Perform a wiggle test on harness while monitoring signal to detect intermittent faults

Signal parameters

Typical sensor output: an analog position signal, normally varies within ~0.5–4.5 V as actuator moves (vehicle-specific)
Circuit-high condition: signal held near supply (~>4.5–5 V) or pulled toward battery voltage if shorted to 12 V
Reference supply: usually ~5 V from ECM; ground should be low (
Thresholds and exact voltages are manufacturer-specific—confirm with vehicle service data

Diagnostic algorithm

Record freeze-frame/live data and note when the fault sets (cold start, warm, under load, etc.).
Inspect the sensor connector and wiring harness for visible damage, corrosion, or melted insulation; repair as needed.
With ignition ON (engine off), backprobe the sensor connector: verify reference voltage (≈5 V), signal voltage, and ground presence. A high signal with correct reference suggests short on signal wire.
If signal is high, disconnect the sensor and measure the signal circuit at the harness side: if still high, suspect short to battery or ECM; if it goes low/open, suspect sensor.
Check continuity from the sensor signal pin to the ECM pin for shorts to power or other circuits and for opens. Repair any shorts/opens found.
If wiring checks OK, install a known-good sensor (or bench-test sensor if possible) and re-scan. If code clears and does not return, replace sensor.
If replaced sensor does not fix and wiring is verified, test or substitute ECM only after confirming all other possibilities—ECM faults are uncommon.
After repairs, clear codes and perform a road/test drive and recheck for recurrence.

Likely causes

Damaged or pinched harness between sensor and ECM causing short to 12V
Connector corrosion or bent pins at sensor/ECM producing high voltage reading
Failed sensor electronics (internal short or internal reference fault)
Intermittent wiring fault aggravated by engine movement (wiring chafe)
Failed VVT actuator causing abnormal sensor output

Fault status

⚠️ Status

Camshaft Position Actuator Position Sensor A Circuit High — Bank 2. ECM detecting sensor voltage above expected range for bank 2 camshaft actuator position sensor; may cause MIL and performance limitations.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours