P0370: Timing Reference High Resolution Signal A
Do not keep driving
Expect reduced performance and possibly a limp mode. The engine will generally still run on the primary crankshaft signal, but timing precision and misfire protection are compromised until it is repaired.
What this code means
A fault in the high-resolution timing reference — a second, much finer crankshaft signal that some engines carry alongside the main one. Where the primary crank sensor might produce dozens of pulses per revolution, this produces hundreds, which is what makes precise injection timing and reliable per-cylinder misfire detection possible at high engine speed.
Losing it does not usually stop the engine, because the primary signal remains. What it costs is precision: injection timing falls back to coarser control, and misfire detection becomes unreliable at exactly the engine speeds where misfires do the most damage.
Likely causes
Start here
- Faulty crankshaft position sensor · moderate
- Damaged reluctor or tone ring · specialist
- Corroded or loose connector · easy
Less common
- Damaged sensor cable shielding · moderate
- Metal debris on the sensor tip · easy
Rare
- Failed control module · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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