P0322 Code: Engine Speed Input Circuit No Signal
P0322: Trace the Missing Speed Input
Confirm that a signal should exist, identify its actual source and determine whether it is generated and reaches the controller.
DIAGNOSTIC FOCUS
- FAULT TYPE
- Missing monitored engine-speed information
- FIRST CHECKS
- Actual source, cranking context, electrical support and signal path
No signal is not simply low RPM, and the generic distributor wording does not identify a distributor on every engine.
P0322 means Ignition/Distributor Engine Speed Input Circuit No Signal. The controller did not receive the expected engine-speed information under its monitoring conditions. Identify the vehicle-specific source before selecting a pickup, ignition component or crankshaft sensor. The generic wording is not a universal parts name.
Save the full scan and starting or stalling history. Confirm actual engine rotation and valid electrical support, then test whether the source generates the required signal and whether it reaches the receiving controller. A zero-RPM display alone does not establish which component or wire failed.
What Does the P0322 Code Mean?
Ignition/distributor is historical diagnostic wording. Modern engines may obtain speed input without a conventional distributor. Use the exact engine diagram and OEM description to identify the monitored source and signal route before ordering parts.
Interpret no signal in the required operating state. Zero RPM with the engine stopped is expected. During no-start diagnosis, confirm actual engine rotation and whether the conditions for expecting an input are satisfied.
The signal may never be generated, lose electrical support, disappear along the harness or fail at the receiving module. Mechanical rotation or target defects require supporting evidence. A missing scan value does not prove a failed crank sensor.
Identify the actual pickup, reference electronics and receiving controller.
Record engine rotation, cranking support and the original event.
Determine whether the signal exists at its source and reaches the required input.
P0322 Symptoms, Severity, and Driving Safety
Preserve the event without exceeding the starter's permitted duty cycle.
Stop unsafe operation and arrange diagnosis rather than repeated traffic tests.
Confirm parameter support, actual rotation and measurement context.
Record temperature and time context without assuming a heat-failed sensor.
Compare their timing and relevance before deciding on a common cause.
Stop further attempts and obtain qualified inspection.
Prompt no-start diagnosis; repeated stalling requires stopping
P0322 Causes and the Evidence That Separates Them
These six branches describe reasons to test the actual signal path. They are not ranked causes or proof that any listed component has failed. The engine architecture determines which electrical supports and physical targets exist.
Disconnected or poorly retained source connector
The expected input may be interrupted at a connector after service or through contact deterioration.
How to prove it: Inspect the correct connection and retention using approved terminal checks. Do not mistake a nearby cam or knock-sensor connector for the speed source, or enlarge terminals with unsuitable probes.
Confirm connector seatingOpen, short or unwanted connection in the harness
The source signal may fail to reach its destination or be distorted along the route.
How to prove it: Compare the approved source and receiver test points with the required connection states. Use suitable signal equipment; an inappropriate continuity test alone cannot establish a healthy operating waveform.
Trace signal continuityMissing sensor or reference-electronics support
An active pickup or intermediary module may lack the electrical conditions it needs.
How to prove it: Identify the actual technology before testing supply and returns. Do not assume every pickup is powered, uses the same voltage or can be evaluated with a generic resistance check.
Check required supportFailed or incorrect speed pickup or reference electronics
The identified source may not produce the required information despite correct support and rotation.
How to prove it: Check the correct part and capture source output using the specified method. A zero scan RPM reading alone does not prove source failure; verify the physical signal and its necessary conditions.
Prove source outputTarget, clearance or mechanical-rotation problem
The source may not encounter the expected target or mechanical relationship.
How to prove it: Use the actual inspection and waveform evidence before this conclusion. Do not prescribe a universal air gap, assume a jumped timing belt or continue cranking through abnormal mechanical sounds.
Inspect rotation and targetController input or replacement-configuration issue
A receiving module or incorrect setup remains possible after external paths are tested.
How to prove it: Prove the required signal reaches the correct input with valid module support. Confirm parts and current service applicability before configuration or controller work; no-signal wording alone does not justify replacement.
Validate receiver branchA missing input at the controller and a missing output at the source are different observations. Keep measurement locations and test conditions in the record so wiring, support and source defects are not combined into an unexplained parts list.
Using MA200 Plus During P0322 Diagnosis
The iCARZONE MA200 Plus can help retrieve supported engine faults and inspect available cranking RPM or related status on a covered vehicle. Preserve full descriptions and companion records before disconnecting components or clearing the original no-start event.
Confirm the required RPM and synchronization parameters. General engine diagnostics do not guarantee every OEM speed input, cam/crank status or module record. Check vehicle and ECU support, parameter identity and update behavior before using one display as diagnostic evidence.
A scan tool reports processed controller data, not an independent pickup waveform. Zero or stale RPM may reflect several conditions and must be interpreted with actual rotation and electrical testing. Use appropriate signal equipment at the specified points when the procedure requires source-to-controller comparison.
iCARZONE MA200 Plus Multi-System OBD2 Diagnostic Scanner
Preserve the no-start or stall record and identify the actual speed-input source before tracing its physical signal path.
No reset or active test is offered as a universal no-signal repair. Do not bypass interlocks, command unsafe cranking or use starting fluid to work around missing information. After repairing the demonstrated branch, perform only the setup and verification required for that exact engine and component.
How to Diagnose P0322 in 6 Steps
Use these six stages with current engine-specific diagrams and pinpoint instructions. They define the source technology, expected rotation, support conditions, suitable instruments and safe cranking limits. No universal waveform, resistance range or pickup air gap is prescribed.
P0322 Quick Diagnostic Path
-
1
Save the full scan and starting history
- Record the complete descriptions, reporting modules, status and available event data before resetting or disconnecting anything.
- Distinguish no-crank, cranks-but-will-not-start and running stalls. Retain recent wiring or engine work and stop repeated attempts if unsafe conditions develop.
-
2
Identify the actual monitored source
- Use engine and controller information to map the pickup or reference electronics and their connection to the receiving module.
- Do not infer a conventional distributor, crank sensor location or connector from generic terminology. Confirm the actual circuit role and source technology.
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3
Verify rotation and the required support
- Follow the appropriate checks for actual engine rotation, cranking conditions and the electrical supports needed by the source and controller.
- An engine-off zero reading is not proof of a fault. Respect starter duty-cycle limits and do not bypass interlocks or ignore abnormal mechanical noise.
-
4
Measure source output with appropriate equipment
- Capture the expected signal at the prescribed source points using the actual connection state and service method.
- Match the instrument to the sensor technology. A universal resistance test or missing scan PID cannot substitute for the required waveform or electrical observation.
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5
Compare the receiving input and isolate the loss
- Determine whether the valid source information reaches the specified controller input and compare relevant reference signals when required.
- Trace wiring and support defects before module conclusions. If source output is absent, use evidence to distinguish electrical support, source condition and target or rotation problems.
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6
Repair the evidenced branch and verify
- Correct the demonstrated connection, source, support or physical defect and restore specified retention, routing and protection.
- Complete required setup and verify reliable starting or running and the relevant monitor. Retain final data; one successful start or a cleared code is insufficient.
How to Fix P0322 and Verify the Repair
Restore the proven signal connection
Repair the actual connector or conductor defect and its underlying routing or retention cause.
Correct a demonstrated support problem
Restore the identified supply or return appropriate to the actual source technology.
Replace a verified failed or incorrect source
Use the correct pickup or reference component with required setup.
Repair evidenced target or receiver conditions
Follow the physical or module test results rather than assuming a universal crank sensor or distributor repair.
No-signal diagnosis
VIN-specific quoteAsk whether actual rotation and source-to-controller comparison are included.
Electrical-path repair
VIN-specific quoteRequest the measured location where support or signal is lost.
Source or mechanical work
VIN-specific quoteRequire the evidence, correct component identity and required access before authorizing replacement.
Final verification
VIN-specific quoteInclude required setup, reliable operation and final signal or monitor records.
Request an itemized estimate after identifying the failed branch. A connector repair, pickup replacement and mechanical target issue require different work. P0322 does not establish a universal price or justify replacing the entire ignition system.
If the event returns, compare the original source, measurement points and conditions. Review intermittent contacts, unresolved support or incorrect parts before further replacement. Preserve evidence instead of repeatedly clearing the warning.
P0322 OEM Differences and DIY Limits
Volkswagen's February 2014 Passat reference book gives engine-code-specific P0322 examples in which engine-speed information is absent while camshaft activity is present. This illustrates a monitored relationship that indicates speed information should be available; it does not identify a conventional distributor or automatically prove the speed pickup failed.
The VW examples compare missing speed information with cam activity.
Different engine sections retain their own criteria.
The source, wiring and receiving input still require diagnosis.
The same book contains different engine sections and counting criteria. Those values are not transferred here. Obtain current VIN-specific information for the actual source, receiving input, waveform and safe operating conditions. A historical monitor table cannot replace the physical circuit test or establish a universal cranking duration.
- Save exact codes and starting behavior.
- Record whether the engine actually cranks.
- Note recent electrical or engine work.
- Ask where the signal is proven absent.
- Do not order a distributor from the generic wording.
- Do not bypass starting interlocks.
- Do not use a universal pickup-resistance value.
- Do not continue driving a vehicle that repeatedly stalls.
Frequently Asked Questions About P0322
What does P0322 mean?
Does my engine definitely have a distributor?
Does zero RPM on the scanner prove a bad sensor?
Is this simply low engine speed?
Should I replace the crankshaft sensor first?
Can MA200 Plus show the physical waveform?
Can I keep cranking until it starts?
What verifies the repair?
Sources and Technical Review Notes
- Autel published DTC reference glossary — Confirms ignition/distributor engine-speed input circuit no signal and adjacent monitor categories.
- Volkswagen Passat reference book, February 2014 — Scoped examples of missing speed information despite camshaft activity; engine-specific counting limits are not generalized.
- Tags: DTC iCARZONE MA200 Plus OBD-II P0322
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