P34B7

Code

Generic P — Powertrain

B Camshaft Position Actuator Temperature Sensor Circuit High Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 24 EN: 32 RU: 30

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Page language: EN

Causes

Open or shorted sensor wiring (short to battery/12V)
Corroded, loose, or damaged connector at the sensor or PCM
Failed camshaft actuator temperature sensor (internal fault)
Poor or missing ground or reference voltage from PCM
PCM or engine control module fault (rare)
Heat damage to wiring harness near exhaust or cylinder head

Symptoms

Check Engine Light (MIL) illuminated
Stored camshaft/cam actuator related fault codes
Possible degraded camshaft actuator performance or timing control
Engine running irregularities if PCM goes into limp mode (depending on vehicle)

What to check

Read freeze frame and related codes; note MIL status and readiness
Visual inspection of sensor, connector, and wiring on Bank 1 (look for heat, chafing, corrosion)
Backprobe sensor connector and measure signal voltage with key on / engine off and during run
Check PCM reference voltage and ground circuits for proper values
Measure sensor resistance vs. expected change with temperature (cold vs. warm)
Wiggle test harness while monitoring signal to try to reproduce the fault

Signal parameters

Sensor uses the vehicle 0–5 V signal domain (typical PCM domain)
Normal signal typically varies with temperature (manufacturer-specific). Expect a measurable, smooth change with temperature rather than a stuck-high voltage
A steady voltage near battery voltage (~12 V) or above the expected max indicates a short to power or circuit fault
Open circuit may present as very high voltage or diagnostic high condition depending on PCM interpretation

Diagnostic algorithm

Retrieve DTCs and freeze-frame; record any related camshaft or actuator codes. Check for manufacturer service bulletins.
Perform a careful visual inspection of the sensor, connector, and harness on Bank 1 B actuator; repair obvious damage or corrosion.
With ignition ON (engine OFF), backprobe the sensor connector: verify reference voltage (usually ~5V) and good ground at the connector. If reference or ground missing, trace to PCM.
Measure sensor signal voltage. If the signal reads near battery voltage or a steady out-of-range high value, disconnect the sensor: if voltage returns to normal or changes, suspect sensor or short in harness to power.
Measure sensor resistance/continuity at the sensor terminals (engine cold then warm if possible) and compare to manufacturer spec. Replace sensor if out of spec.
Inspect and test harness for short-to-power: isolate wiring and use an ohmmeter to check for continuity to battery positive. Repair any chafed wires or shorts.
If wiring and sensor test good, substitute a known-good sensor or repair/replace sensor connector. Reconnect and clear codes.
If the code returns after sensor/harness replacement, consider PCM input circuit diagnosis or replacement; consult wiring diagrams and manufacturer tech info before replacing PCM.
After repairs, clear codes and perform a drive cycle to verify the fault does not return and that cam actuator operation is normal.

Likely causes

Short to power in the sensor signal wire
Failed temperature sensor element
Contaminated/corroded connector causing high resistance or false readings
Damaged harness insulation from heat or rubbing leading to intermittent short

Fault status

⚠️ Status

B Camshaft Position Actuator Temperature Sensor Circuit High (Bank 1). The sensor circuit is reporting a higher-than-expected voltage/temperature signal. Possible causes include short to power, faulty sensor, or wiring/connector fault. Further diagnostic testing of the sensor and harness is required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours