P0376

Timing Reference High Resolution Signal B Malfunction

Powertrain Ignition System Timing signal sensor malfunction 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

The engine's computer can't properly read the timing signal from sensor B, which tells it exactly when to fire the spark plugs. It's like a metronome that's out of sync—the engine loses its rhythm and runs poorly.

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Symptoms You May Notice

3 known symptoms for this code
Check Engine Light illuminated
Rough idle or engine hesitation during acceleration
Hard starting or no start condition
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECM monitors the camshaft or crankshaft position sensor B signal for proper frequency, amplitude, and timing edges. The sensor should produce clean, consistent pulses at predictable intervals as the shaft rotates. If signal quality degrades, the ECM cannot establish precise timing references for fuel injection and ignition.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Signal Frequency Consistent pulses matching engine RPM Missing, irregular, or erratic pulse pattern
Signal Amplitude 4-5V peak or manufacturer spec Below 0.5V or exceeding 5.5V consistently
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Camshaft/Crankshaft Position Sensor B
Inspect sensor for dirt or oil contamination, clean or replace if worn.
2
Sensor wiring harness and connectors
Check for corroded, loose, or damaged connectors; reseat or replace damaged wiring.
3
Engine timing belt or chain
Verify timing component is intact and properly tensioned; replace if worn or misaligned.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code P0376 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code P0376

What happens after you fix the fault

Once the fault is repaired, P0376 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.