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P0322 Code: Ignition/Distributor Engine Speed Input Circuit No Signal

P0322 code engine-speed input circuit no-signal diagnostic illustration

The P0322 OBD-II trouble code means the Powertrain Control Module has stopped receiving an expected engine-speed signal from the ignition or distributor input circuit.

The generic definition for P0322 is:

Ignition/Distributor Engine Speed Input Circuit No Signal

Depending on the vehicle, this signal may originate from the:

When that signal disappears, the PCM may no longer know how quickly the engine is rotating or when to trigger ignition and fuel-injector operation. The result can range from an illuminated Check Engine Light to an engine that stalls or refuses to start.

P0322 does not automatically condemn the crankshaft position sensor. Wiring failures, poor grounds, distributor problems, damaged trigger wheels and ignition-module faults can all produce the same code. Replacing the sensor before testing the circuit remains a popular diagnostic strategy, mostly among people who enjoy buying the same repair twice.

P0322 Quick Facts

ItemInformation
Trouble codeP0322
Generic definitionIgnition/Distributor Engine Speed Input Circuit No Signal
SystemIgnition and engine-speed monitoring
SeverityModerate to severe
Safe to drive?Not recommended until diagnosed
Common symptomsStalling, crank-no-start, hard starting, tachometer dropout
Common causesFailed sensor, open circuit, damaged connector, ignition-module failure
Typical diagnostic toolsOBD-II scanner, multimeter, test light and oscilloscope
Related codesP0320, P0321, P0323 and P0335

What Does the P0322 Code Mean?

The PCM needs an accurate engine-speed signal to control:

The exact source of this signal varies by manufacturer.

On one vehicle, the PCM may receive engine-speed information directly from the crankshaft position sensor. Another vehicle may route the signal through an ignition control module or distributor pickup before it reaches the PCM.

P0322 is stored when the PCM expects this input but detects no usable signal.

That distinction matters. P0322 is not merely reporting a signal that is slightly inaccurate. It indicates that the expected signal has disappeared completely—or has dropped low enough that the PCM interprets it as missing.

How the Engine-Speed Input Signal Works

Most modern engines determine crankshaft speed and position using a magnetic or Hall-effect sensor positioned near a toothed reluctor wheel.

As the reluctor wheel rotates, the sensor produces a repeating electrical signal. The PCM uses the frequency and timing of this signal to calculate:

Older distributor-equipped engines may generate the signal through a pickup coil or Hall-effect sensor inside the distributor. Some ignition systems then send a processed engine-speed signal from the ignition module to the PCM.

If the signal circuit becomes open, shorted or disconnected, the PCM may store P0322.

How Serious Is the P0322 Code?

P0322 should be treated as a serious fault because the engine-speed signal is often essential for ignition and fuel control.

Possible consequences include:

A vehicle that stalls while moving can lose power-assisted steering and reduce brake assistance. If the engine is cutting out, avoid driving it until the fault has been diagnosed.

If the Check Engine Light is the only symptom and the vehicle runs normally, the fault may be intermittent. That does not make it harmless. Intermittent electrical problems have a charming habit of returning precisely when the vehicle is farthest from your garage.

Common Symptoms of P0322

Symptoms depend on whether the signal is missing continuously or only drops out occasionally.

Common P0322 symptoms include:

For a broader diagnosis that is not tied to one trouble code, see our guide to an engine that cranks but will not start.

Common Causes of the P0322 Code

The most common P0322 causes include:

  1. Failed crankshaft position sensor
  2. Failed camshaft position sensor
  3. Defective distributor pickup
  4. Failed ignition control module
  5. Open engine-speed signal wire
  6. Signal circuit shorted to ground
  7. Signal circuit shorted to voltage
  8. Loose electrical connector
  9. Corroded connector terminals
  10. Backed-out or damaged terminal pins
  11. Missing sensor power supply
  12. Poor sensor or module ground
  13. Damaged engine wiring harness
  14. Wiring melted against the exhaust
  15. Oil or coolant contamination inside a connector
  16. Damaged crankshaft reluctor wheel
  17. Excessive sensor-to-reluctor air gap
  18. Distributor shaft wear
  19. Incorrectly installed replacement sensor
  20. Incorrect engine or ignition timing
  21. PCM connector damage
  22. PCM failure

PCM failure is possible, but it should remain near the bottom of the list. Computers do fail, but loose connectors and cooked wiring are far less dramatic and considerably more common.

Vehicles Commonly Affected by P0322

P0322 is a generic powertrain code and may appear on many OBD-II-equipped vehicles.

It is frequently associated with applications from:

The exact definition and signal path can vary. Some Volkswagen and Audi applications, for example, may associate P0322 closely with the engine-speed or crankshaft position sensor. Other vehicles may use an ignition-module or distributor-generated input.

Always consult the correct wiring diagram and manufacturer service information for the vehicle being tested.

P0322 Versus P0321, P0320 and P0335

These codes occupy similar diagnostic territory, but they do not describe the same failure.

CodeMeaningPrimary distinction
P0320Ignition/distributor engine-speed input circuit malfunctionGeneral circuit fault
P0321Engine-speed input circuit range/performanceSignal exists but appears implausible
P0322Engine-speed input circuit no signalExpected signal is missing
P0323Engine-speed input circuit intermittentSignal repeatedly drops out and returns
P0335Crankshaft position sensor “A” circuit malfunctionFault specifically assigned to CKP sensor A

The P0322 article should remain focused on identifying a missing input signal. Broader crankshaft-sensor testing belongs with P0335 crankshaft position sensor “A” circuit diagnosis.

What Does “No Signal” Actually Mean?

“No signal” means the PCM did not detect the expected sequence of electrical pulses from the engine-speed input circuit.

This can happen because:

This wording does not prove that the sensor itself has failed.

The sensor could be functioning normally while a broken wire prevents its output from reaching the PCM. That is why circuit testing matters.

Common Scan-Tool Patterns

Live data can quickly narrow the problem before components are removed.

Zero RPM During Cranking

Crank the engine while monitoring engine RPM.

If the scan tool remains at 0 RPM, possible causes include:

A 0 RPM reading strongly supports a missing engine-speed signal, although the vehicle’s specific data strategy should still be verified.

RPM Appears Normally During Cranking

If the scanner displays a stable cranking speed—typically around 150 to 300 RPM—the PCM is receiving at least some engine-speed information.

In this situation:

Check freeze-frame information and manufacturer service procedures before clearing the code.

RPM Drops to Zero Before the Engine Stalls

If engine RPM suddenly falls to zero on the scanner while the crankshaft is still turning, suspect an electrical signal dropout.

Possible causes include:

This is especially useful when the engine stalls after warming up.

RPM Signal Is Erratic

A jumping or unstable RPM reading may indicate:

An erratic signal may eventually set P0321 or P0323 instead of P0322, depending on how the PCM interprets the failure.

How to Diagnose the P0322 Code

Proper diagnosis requires identifying which component generates the engine-speed input and determining where that signal disappears.

Step 1: Scan All Control Modules

Connect a capable OBD-II scan tool and record:

Do not erase the codes before recording this information. Freeze-frame data may show whether P0322 occurred during startup, idle, acceleration or a stall.

Check for related codes involving:

Low battery voltage during cranking can distort sensor and module operation, so battery condition should be verified early.

Step 2: Identify the Signal Source

Use the correct wiring diagram to determine where the PCM receives its engine-speed input.

The source may be:

Do not assume every P0322 diagnosis begins and ends at the crankshaft sensor. The code description deliberately includes “ignition/distributor” because vehicle designs differ.

Step 3: Monitor RPM While Cranking

Disable the engine from starting if required by the service procedure, then crank it while watching engine RPM on the scan tool.

Results:

If the engine starts and stalls, graph the RPM parameter and watch for signal loss immediately before shutdown.

Step 4: Inspect the Sensor and Wiring

Inspect the relevant sensor, ignition module and wiring harness.

Look for:

Perform a light wiggle test while monitoring live data. If RPM or signal status changes, inspect that section of the harness closely.

Avoid yanking on old wiring like you are starting a lawn mower. Brittle insulation rarely appreciates the enthusiasm.

Step 5: Check Battery Voltage

Low cranking voltage can prevent the PCM, sensor or ignition module from operating correctly.

Test:

Many vehicles require cranking voltage to remain above approximately 9.6 volts, but the correct specification depends on the manufacturer.

Repair a weak battery, damaged terminal or excessive voltage drop before continuing.

Step 6: Test Sensor Power and Ground

For a Hall-effect sensor, verify:

Many Hall-effect sensors use a 5-volt or battery-voltage supply, but specifications vary.

A missing reference voltage may result from:

Check ground quality with a voltage-drop test whenever possible. A circuit can show continuity and still fail under load.

Step 7: Check the Signal Circuit

Back-probe the signal circuit using the manufacturer’s procedure.

Check for:

Disconnect the appropriate modules before performing resistance or continuity tests. Applying meter voltage to a connected controller circuit can produce misleading readings or damage sensitive electronics.

Step 8: Inspect the Sensor Waveform

An oscilloscope is the best tool for evaluating a crankshaft, distributor or engine-speed signal.

A healthy waveform should have:

A magnetic sensor normally produces an AC waveform whose amplitude increases with engine speed. A Hall-effect sensor typically switches between low and high voltage.

Watch for:

Do not apply universal waveform or resistance specifications. Sensor designs vary too much for one internet number to rule them all.

Step 9: Inspect the Reluctor Wheel or Distributor

If the sensor circuit tests correctly, inspect the mechanical trigger.

Possible problems include:

A perfect new sensor cannot read a reluctor wheel that is broken, loose or nowhere near it.

Step 10: Test the Ignition Control Module

On vehicles that route the engine-speed signal through the ignition control module, verify:

If the module receives a valid position signal but does not produce the expected output, the module or its related circuit may be defective.

Step 11: Verify the PCM Input

Only evaluate the PCM after verifying:

If a valid engine-speed waveform reaches the correct PCM terminal but scan data still reports no input, PCM diagnosis may be justified.

Check for software updates and technical service bulletins before replacing or programming the controller.

Common Diagnostic Mistakes

Avoid these common P0322 mistakes:

The code tells you what the PCM stopped seeing. It does not mail you the failed component’s part number.

How to Fix the P0322 Code

The correct repair depends on the test results.

Possible P0322 repairs include:

After completing the repair:

  1. Clear the stored codes.
  2. Start the engine.
  3. Monitor engine RPM and synchronization data.
  4. Reproduce the original operating conditions.
  5. Complete the required drive cycle.
  6. Rescan for pending and stored codes.

A code that does not immediately return is not automatically repaired. Intermittent failures may require an extended road test or heat-soak test.

Estimated P0322 Repair Costs

Repair costs vary by vehicle, labor rate and the failed component.

RepairTypical estimated cost
Electrical diagnosis$100–200
Connector or minor wiring repair$75–300
Crankshaft position sensor replacement$150–450
Camshaft position sensor replacement$150–400
Distributor pickup repair$200–600
Ignition control module replacement$200–700
Reluctor wheel repair$500–2,000+
PCM replacement and programming$800–2,500+

These are broad estimates. Sensor access can turn a relatively inexpensive component into a labor-intensive repair.

Can You Drive With a P0322 Code?

Driving with P0322 is not recommended if the vehicle exhibits:

If the engine runs normally and only the Check Engine Light is present, drive only as necessary to reach a safe repair location.

An engine-speed input failure can shut the engine down without much warning. That makes postponing diagnosis a questionable gamble, particularly in traffic.

Will P0322 Cause a No-Start Condition?

Yes. P0322 can cause an engine to crank without starting.

If the PCM cannot detect crankshaft rotation, it may disable:

However, a crank-no-start condition has many possible causes. Confirm that scan-tool RPM remains at zero and test the appropriate signal circuit before replacing parts.

Can a Weak Battery Cause P0322?

A weak battery can contribute to P0322 if cranking voltage falls low enough to disrupt the:

Battery condition should always be checked when P0322 appears with slow cranking, low-voltage codes or multiple unrelated electrical faults.

Can a Bad Crankshaft Sensor Cause P0322?

Yes. A failed crankshaft position sensor is one possible cause, particularly when the PCM uses that sensor as its primary engine-speed input.

It is not the only possible cause.

The same missing signal can result from:

Test the entire signal path before replacing the sensor.

Does P0322 Always Mean There Is No Spark?

No. Some vehicles may continue producing spark temporarily or use separate ignition and engine-speed circuits.

However, if the missing input is required for ignition timing, P0322 can occur with no spark and no injector pulse.

Verify spark, injector command and scan-tool RPM instead of assuming all three conditions are present.

Related Pro Street OBD-II Resources

Use these guides to continue the diagnosis without turning every ignition-related code into one giant keyword casserole:

Final Thoughts

The P0322 code means the PCM is not receiving an expected signal from the ignition or distributor engine-speed input circuit.

A failed crankshaft position sensor is a common possibility, but it is not a guaranteed diagnosis. Damaged wiring, poor electrical connections, missing sensor power, ignition control module failure, distributor problems and damaged reluctor wheels can all interrupt the signal.

Begin by checking battery voltage, recording all codes and monitoring engine RPM during cranking. Then identify the vehicle’s actual signal source and test the circuit from the sensor or ignition module to the PCM.

The goal is not merely to replace the component most frequently mentioned beside P0322. The goal is to find where the signal disappears—which is slightly less exciting than firing the parts cannon, but considerably cheaper.

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