CKP · ENGINE SPEED · SYNCHRONIZATION
Crankshaft position sensor: signal, air gap, cranking and synchronization file
IDENTITYLock down the exact variant
A marketing name is not a service identity.
- Identify Hall/inductive type, part number, air gap, trigger wheel and mounting.
- Confirm how the ECU uses CKP for speed, injection/ignition and cam synchronization.
- Record starter, battery, flywheel/flexplate, clutch and timing-work history.
- Note whether failure occurs hot, cold, during cranking, vibration or at a specific rpm.
ARCHITECTURE & DATARead the system through measured channels
Use a related data chain, not one screen.
- During cranking observe rpm PID, battery voltage, sync state and injection/ignition enable.
- Capture inductive amplitude/frequency or Hall square wave together with power/ground.
- Record crank and cam together to separate signal dropout from true phase shift.
- Observe the harness under controlled heat, vibration and engine movement.
DIFFERENTIALSeparate similar symptoms by root cause
Expensive replacement follows evidence.
- If signal is absent, inspect cranking speed, air gap, trigger-wheel damage, supply and wiring alongside the sensor.
- If signal disappears hot, separate internal sensor failure, connector expansion and wiring resistance.
- If rpm exists but synchronization does not, compare cam signal, mechanical timing and trigger-wheel position.
- Random stalling can be ECU power/main-relay/network loss rather than CKP.
VALIDATIONValidate the repair reproducibly
Code clearing or a short drive is not enough.
- Repeat waveform capture during cold start, hot soak/restart and vibration.
- Cranking speed and synchronization time should return to reference behaviour.
- Run across rpm/load without crank-cam correlation or misfire codes.
- Complete several heat cycles without pending CKP/synchronization codes.
TECHNICAL SOURCESPrimary and official sources
- Engine management systems and speed/position sensing · Bosch Mobility
- Crankshaft speed sensor data sheet · Bosch Mobility
- SAE J2012 Diagnostic Trouble Code Definitions · SAE International
- Vehicle Safety and Manufacturer Communications · NHTSA
This file is not a parts-replacement list. Exact values should be used only after VIN, engine/transmission code, production period, software, test conditions and the manufacturer procedure are aligned.
FROM THEORY TO MEASURABLE EVIDENCE
System operation and failure analysis
MEASUREMENTSignals that produce evidence
- Command, feedback, supply, ground and physical response belong in one measurement plan.
- Do not conclude from static measurements without reproducing the fault condition.
FAILURE CHAINSeparate similar symptoms
- Test mechanical binding, electrical loss and software/calibration effects as separate hypotheses.
VALIDATIONProve the repair is complete
- Reproduce the original fault condition.
- Check pending/permanent codes and monitor status.
- Verify no new network or low-voltage codes appear in related modules.
Overview
Crankshaft-position sensor is evaluated through its operating principle, supply, ground, signal, physical target and controller interpretation.
The test method must match the sensor technology. Power and ground are load-tested, while analogue, frequency or digital signals are compared with scan-tool live data.
Cleaning and installation procedures are sensor-specific; aggressive solvents, physical contact with sensing elements and unverified adjustments are avoided.
Identity and Key Facts
- Knowledge domain
- Technical foundation
- Connected category
- sensor-families
- Verification
- Source and vehicle variant are evaluated together
Technical depth link
Read this record through operating principle, energy/network relationships, measurements and failure patterns, not the part name alone.
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