Ignition/Distributor Engine Speed Input Circuit No Signal
The PCM is not receiving a valid engine speed signal from the crankshaft position sensor or ignition/distributor circuit. Without this critical input, the engine cannot determine ignition timing or fuel injection, preventing normal operation. This code indicates a complete loss of engine speed input to the computer.
What You Might Notice
- Engine cranks but will not start
- Malfunction Indicator Light (Check Engine) illuminated
- Misfires, hesitation, and stumbling during acceleration
- Loss of engine power or inability to maintain idle
- Stalling while driving
Most Common Causes
- 1
Faulty Crankshaft Position Sensor
The CKP sensor has failed or is producing an out-of-range signal. This is the most common cause of P0322 codes as the sensor is exposed to engine heat and vibration.
- 2
Open or Broken Wiring to Sensor
A break, corrosion, or disconnect in the control circuit (ground) or power supply circuit between the sensor and PCM prevents signal transmission. Check connectors and harness for damage.
- 3
Short to Ground in Power Supply Circuit
The positive power supply wire to the sensor is shorted to ground, cutting off voltage to the sensor and preventing it from operating.
- 4
PCM Failure
The powertrain control module itself has failed and is unable to recognize or process the engine speed input signal, though this is less common than sensor failure.
How to Diagnose It
- 1
Check Faulty Crankshaft Position Sensor — The CKP sensor has failed or is producing an out-of-range signal. This is the most common cause of P0322 codes as the sensor is exposed to engine heat and vibration.
- 2
Check Open or Broken Wiring to Sensor — A break, corrosion, or disconnect in the control circuit (ground) or power supply circuit between the sensor and PCM prevents signal transmission. Check connectors and harness for damage.
- 3
Check Short to Ground in Power Supply Circuit — The positive power supply wire to the sensor is shorted to ground, cutting off voltage to the sensor and preventing it from operating.
- 4
Check PCM Failure — The powertrain control module itself has failed and is unable to recognize or process the engine speed input signal, though this is less common than sensor failure.
How to Fix It
- 1
Replace Crankshaft Position Sensor
Remove the faulty sensor from the engine block or timing cover and install a new OEM or equivalent sensor. Ensure proper gap and alignment if applicable. This resolves the issue in most cases.
- 2
Inspect and Repair Sensor Wiring
Check the connector pins, wiring harness, and grounds between the sensor and PCM for corrosion, breaks, or loose connections. Repair or replace damaged wiring and reseat connectors firmly.
- 3
Test and Replace PCM if Needed
After confirming the sensor and wiring are functioning correctly, use a diagnostic scan tool to verify PCM communication. If the PCM is not responding to sensor input, it may require replacement or reprogramming.
- 4
Clear Code and Verify Operation
After repairs, clear the DTC with a scan tool and perform a test drive to confirm the engine starts, runs smoothly, and the code does not return. Monitor for recurrence.
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