P0321 code definition
Ignition/Distributor Engine Speed Input Circuit Range/Performance
What the P0321 code means
P0321 is an OBD-II generic code that the engine control module (ECM) detected the engine speed input sensor circuit out of range or its performance is not within specifications. The sensor may also be called a RPM sensor.
What causes the P0321 code?
The engine speed sensor open or shorted internally that would cause the engine to stall or not start.
The wiring or connection to the speed sensor is getting shorted or losing connection intermittently.
What are the symptoms of the P0321 code?
- The Check Engine Light will be illuminated and the code is set in ECM memory.
- The engine would stall or not start if failure is present.
- The engine will have a misfire and may buck or jerk while driving for an intermittent connection.
How does a mechanic diagnose the P0321 code?
Scans codes and documents the freeze frame data in order to verify the problem.
Clears the engine and ETC codes and road tests to verify the concern comes back.
Visually checks the wiring and connections to the engine speed sensor for loose or damaged wiring connections.
Disconnects and checks the resistance and signal voltage from the engine speed sensor.
Checks for any corrosion in the sensor connections.
Checks the sensor reluctor wheel for breakage or damage.
Common mistakes when diagnosing the P0321 code
Failing to check the air gap of the engine speed sensor for intermittent failures or loss of signal.
Failure to repair oil leaks onto the sensor before replacing the sensor.
How serious is the P0321 code?
A failed engine speed sensor will cause the engine to stall or not run at all.
An intermittent engine speed signal from the sensor can cause the engine to run rough, stall, jerk, or misfire while driving.
What repairs can fix the P0321 code?
- Replacing the faulty engine speed sensor.
- Replacing a broken reluctor ring on the crankshaft or damper.
- Repairing corroded connections to the engine speed sensor.
Additional comments for consideration regarding the P0321 code
Code P0321 is triggered when the engine speed sensor does not generate a signal to keep the engine running.
Need help with a P0321 code?
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