10d. Check The RPM Signal While Cranking
10d. CHECK THE RPM SIGNAL WHILE CRANKINGNOTE:
- The scan tool may reset if the system voltage drops below 9.5 volts. You may need to use an outside voltage source for the scan tool.
- No FICM synchronization while cranking the engine with correct ICP, RPM and VPWR signals usually indicates a loss of the CMP or CKP synchronization signal. Refer to Reference Values, Typical Diagnostic Reference Values for normal operating values. Typical Diagnostic Reference Values
Purpose:
This purpose of this test is to verify the CKP sensor, the CMP sensor, and related circuits are functioning.
Data List
Select the parameters indicated from the scan tool parameter list and monitor while cranking the engine.
Recommended Procedure:
- Connect the scan tool.
- Ignition ON, engine OFF.
- Monitor the RPM while cranking the engine.
Possible Causes:
- Low battery voltage
- High resistance in the starting system
- Charging system
- CKP sensor
- CMP sensor
GO to Pinpoint Test D to diagnose a CKP concern. Test D: Crankshaft Position (CKP) Sensor
GO to Pinpoint Test V to diagnose a CMP concern. Test V: Camshaft Position (CMP) Sensor
Tools Required:
Scan Tool