What Does P0376 Mean?
The ECM has detected too many pulses from the timing reference high-resolution signal B sensor. This means the sensor is generating more signal transitions than expected for the given reluctor wheel pattern, suggesting interference, a damaged tone ring with extra edges, or a wiring fault creating false signals. The engine may misfire, exhibit timing instability, or run rough as the ECM receives conflicting position data.
Common Causes
30%
Damaged reluctor ring with burrs, cracks, or extra edges creating false signal transitions
25%
Electromagnetic interference on the sensor B signal wire from nearby ignition or charging system components
20%
Sensor B wiring chafed against engine ground causing intermittent signal spikes
15%
Faulty sensor B generating erratic output voltage spikes
10%
Loose metallic debris near the sensor tip being attracted by the magnetic field
Diagnostic Steps
1
Monitor engine RPM on the scan tool while the engine idles. Look for RPM fluctuations or impossibly high RPM spikes that indicate the ECM is counting extra pulses.
2
Capture the sensor B waveform with an oscilloscope at idle and 2000 RPM. Count the number of pulses per revolution and compare to the expected tooth count on the reluctor wheel. Look for extra spikes between normal teeth.
3
Inspect the reluctor ring or tone wheel visually (may require removing the sensor or using a borescope). Look for burrs from machining, impact damage, or cracks that create additional signal edges.
4
Route the sensor B signal wire away from ignition coil wires, alternator output wires, and other high-current or high-voltage sources. Verify the signal wire shielding is intact and properly grounded.
5
Clean the sensor tip and surrounding area with a non-metallic tool to remove any metallic debris that could be attracted to a magnetic sensor and generate false signals.
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
The ECM has detected too many pulses from the timing reference high-resolution signal B sensor. This means the sensor is generating more signal transitions than expected for the given reluctor wheel pattern, suggesting interference, a damaged tone ring with extra edges, or a wiring fault creating fa...
The most common cause of P0376 (Timing Reference High Resolution Signal B Too Many Pulses) is: Damaged reluctor ring with burrs, cracks, or extra edges creating false signal transitions
Typical repair costs for P0376 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Excess timing pulses can cause erratic ignition timing and misfires. While the engine will typically continue to run, performance is compromised and long-term operation could damage the catalytic converter from misfires. Drive cautiously to a repair facility; avoid heavy acceleration.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0376 to identify the root cause.
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Quick Info
Category
Powertrain
System
Ignition / Engine Timing System
Difficulty
Type
Generic (SAE)
Recommended Tools
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