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Install a scan tool. Verify that the scan tool powers up.
If the scan tool does not power up, refer to Scan Tool Does Not Power Up.
Ignition ON, Engine OFF, verify communication with all of the control modules
on the vehicle.
If the scan tool does not communicate with one or more of the expected control
modules, refer to Scan Tool Does Not Communicate with CAN Device.
Verify that SPN 65559 is not set.
If SPN 65559 is set, refer to SPN 65559.
Attempt to start the engine. Verify that the engine cranks.
If the engine does not crank, refer to SPN 66001 or SPN 66002 (if equipped). If
the vehicle is not equipped with an ECM controlled starter relay, repair the
starting system.
Attempt to start the engine. Verify the engine starts and idles.
If the engine does not start and idle, refer to Engine Cranks But Does Not Run.
Important: Do not clear any SPNs unless instructed to do so by a diagnostic
procedure.
Use the appropriate scan tool selections to obtain SPNs from each of the vehicle
modules. Verify there are no SPNs reported from any module.
_ If any SPNs are present, refer to Diagnostic Trouble Code (DTC) List and
diagnose any current SPNs in the following order:
Any of the following: 630, 65580, 65581, or 65582.
SPN 627.
Component level SPNs.. System level SPNs.
Any remaining SPNs.
_ If none of the previous tests or inspections addresses the concern, refer to
Symptoms - Engine Controls.
SPN 94
SPN Descriptors
SPN 94 FMI 3: Fuel Pressure Sensor Voltage Above Normal or Shorted High
SPN 94 FMI 4: Fuel Pressure Sensor Voltage Below Normal or Shorted Low
SPN 94 FMI 15: Fuel Pressure Data Valid But Above Normal Range-Least
Severe Level
SPN 94 FMI 17: Fuel Pressure Data Valid But Below Normal Range-Least
Severe Level
SPN 98
SPN Descriptor
SPN 98 FMI 17: Oil Level Switch Signal Data Valid But Below Normal Range-
Least Severe Level
