Pinpoint Test K: P0634
- NOTE: The Secondary Inverter System Controller (S-ISC) is referred to as the SOBDMB (Secondary On-Board Diagnostic Control Module B) in the scan tool.
Normal Operation and Fault Conditions
REFER to: Front Electric Drive Assembly - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition SOBDMB P0634:00 Control Module Internal Temperature "A" Too High: No Sub Type Information This DTC sets when the internal circuit board reports an over-temperature condition. Possible Sources
- Electric Powertrain Cooling Concern
- Secondary Inverter System Controller (S-ISC)
- K1 CHECK FOR SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, perform the Secondary Inverter System Controller (S-ISC) self-test.
- Record the Secondary Inverter System Controller (S-ISC) DTCs.
- Using a diagnostic scan tool, perform the BECM self-test.
- Record the BECMDTCs
Are any Secondary Inverter System Controller (S-ISC) or BECMDTCs present?
Yes For any BECM DIAGNOSE the BECMDTCs first. REFER to: High Voltage Battery, Mounting and Cables . For any Secondary Inverter System Controller (S-ISC) other than DTC P0634, DIAGNOSE all other Secondary Inverter System Controller (S-ISC) DTCs. REFER to Diagnostic Trouble Code (DTC) Chart . For DTC P0634 only GO to K2 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - K2 CHECK THE COOLING FAN AND ACTIVE GRILLE SHUTTER OPERATIONNOTE: Verify radiator cooling fan operation before proceeding with this test
- Verify the cooling fan and active grille shutters operate correctly.
Do the active grille shutters and cooling fan operate correctly?
Yes GO to K3 No REFER to: Active Grille Shutter . - K3 CHECK THE COOLANT LEVEL
- Inspect the coolant.
Is the coolant at the correct level?
Yes GO to K5 No REFER to: Electrified Drivetrain Cooling System Draining, Vacuum Filling and Bleeding . - K4 CHECK FOR A RECENT COOLANT FILL
- Inspect the coolant for signs of a recent fill.
Has the coolant system been recently filled?
Yes PERFORM the system fill procedure to bleed air from the system, add coolant if needed. REFER to: Electrified Drivetrain Cooling System Draining, Vacuum Filling and Bleeding . No GO to K5 - K5 INSPECT THE COOLANT FOR CONTAMINATION
- Inspect the coolant.
Is the coolant contaminated?
Yes REFER to: Electrified Drivetrain Cooling System Draining, Vacuum Filling and Bleeding . No GO to K6 - K6 INSPECT THE RADIATOR
- Inspect the radiator for any obstruction.
Is the radiator obstructed?
Yes REPAIR as necessary. No GO to K7 - K7 INSPECT THE MOTOR ELECTRONICS COOLING SYSTEM HOSES
- Inspect the motor electronics cooling system hoses for kinks, leaks, improper routing or connections.
Is a concern present?
Yes REPAIR as necessary. No GO to K8 - K8 INSPECT FOR INTERNAL AND EXTERNAL COOLANT LEAKS
- Inspect the coolant system for leaks.
Are any leaks present?
Yes REPAIR as necessary. No GO to K9 - K9 CLEAR AND CHECK THE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) DIAGNOSTIC TROUBLE CODES (DTCS)
- Ignition ON.
- Using a diagnostic scan tool, clear the Inverter System Controller (S-ISC) DTCs.
- Using a diagnostic scan tool, perform the Secondary Inverter System Controller (S-ISC) self-test.
Is Secondary Inverter System Controller (S-ISC) DTC P0634 present?
Yes For DTC P0634 only, CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new Secondary Inverter System Controller (S-ISC). No DIAGNOSE any other remaining Secondary Inverter System Controller (S-ISC) DTCs, REFER to Diagnostic Trouble Code (DTC) Chart .