This code indicates the engine computer has detected more timing pulses than expected from the high-resolution sensor designated "Signal B," typically a crankshaft or camshaft position sensor. The excessive count suggests false triggers caused by electrical faults, physical damage to the timing wheel, or sensor malfunction.
The crankshaft or camshaft position sensor (Signal B) may have an internal short or electrical fault causing it to generate extra pulses, or its output may be skewed by contamination.
A cracked, chipped, or loose reluctor ring can create false triggers, as can metallic debris accumulated on the sensor tip, both causing the sensor to register extra edges.
The sensor signal wire shorted to ground or voltage, or cross-talk from high-current aftermarket circuits, can induce phantom pulses the PCM interprets as valid timing signals.
A sensor mounted too close to the trigger wheel, or a loose sensor bracket, may cause double-triggering on each tooth edge due to excessive signal amplitude or oscillation.
Rarely, a malfunction within the engine computer’s input processing circuit may miscount valid pulses; this should only be considered after all sensor, wiring, and mechanical causes are ruled out.
It designates a specific high-resolution timing input circuit, often a secondary crankshaft position sensor or a specific bank’s camshaft sensor, depending on the vehicle’s sensor architecture.
No. The engine can stall without warning or fail to restart, which creates a safety risk in traffic.
Usually no. PCM failure is a rare cause of this code. Replacing the module without first testing the sensor, wiring, and trigger wheel often wastes money and does not resolve the issue.
Extra pulses typically originate from physical debris on the sensor, a cracked trigger wheel flapping, electrical interference, or a shorted sensor winding that creates false trigger events.