DTC C1423 Different Ecu Specifications: Trouble symptom

ABS does not operate.
VDC does not operate.
Hill start assist does not operate.
Hill descent control does not operate. (Model with X mode)
EyeSight does not operate. (Model with EyeSight)

NOTE: When parameter selection for VDCCM is improper, this DTC may be memorized.

CHECK VDCCM&H/U IDENTIFICATION SYMBOL.
Check the identification symbol attached on the H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>General Description>SPECIFICATION .

Is the identification symbol correct?
- Yes : Go to 2.
- No : Replace the VDCCM&H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC Control Module and Hydraulic Control Unit (VDCCM&H/U) .
CHECK PARAMETER SELECTED IN VDCCM.
Ref. to BRAKE CONTROL (DIAGNOSTICS)>Subaru Select Monitor>OPERATION>PARAMETER CHECK .

Does the parameter registered in the VDCCM match the relevant vehicle?
- Yes : CVT model: Go to 3.
  MT model: Go to 5.
- No : Select and register the correct parameter. Ref. to BRAKE CONTROL (DIAGNOSTICS)>Subaru Select Monitor>OPERATION>PARAMETER SELECTION .
CHECK TCM SPECIFICATION.
Check the TCM specification.

Is the specification of TCM same as vehicle specification?
- Yes : Go to 4.
- No : Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Transmission Control Module (TCM) . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Transmission Control Module (TCM) .
CHECK CVT SYSTEM.
1. Start the engine.
2. Read the DTC of the CVT system. Ref. to TRANSMISSION (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .
Is DTC of CVT system displayed?
- Yes : Perform the diagnosis according to DTC. Ref. to TRANSMISSION (DIAGNOSTICS)>List of Diagnostic Trouble Code (DTC) .
- No : Go to 5.
CHECK ECM SPECIFICATION.
Check the ECM specification.

Is the specification of ECM same as vehicle specification?
- Yes : Go to 6.
- No : Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Engine Control Module (ECM) . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Engine Control Module (ECM) .
CHECK ENGINE SYSTEM.
1. Start the engine.
2. Read DTC of the engine system. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Read Diagnostic Trouble Code (DTC) . Ref. to ENGINE (DIAGNOSTICS) (H4DO)>Read Diagnostic Trouble Code (DTC) .
Is engine system DTC displayed?
- Yes : Perform the diagnosis according to DTC. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>List of Diagnostic Trouble Code (DTC) . Ref. to ENGINE (DIAGNOSTICS) (H4DO)>List of Diagnostic Trouble Code (DTC) .
- No : Go to 7.
CHECK VDCCM&H/U.
1. Clear the memory. Ref. to BRAKE CONTROL (DIAGNOSTICS)>Clear memory .
2. Perform the Inspection Mode. Ref. to BRAKE CONTROL (DIAGNOSTICS)>Inspection Mode .
3. Read the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .
Is the same DTC displayed?
- Yes : Replace the VDCCM only. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC Control Module and Hydraulic Control Unit (VDCCM&H/U)>REPLACEMENT .
- No : Go to 8.
CHECK DETECTION OF OTHER DTCS FOR VDC.
Ref. to BRAKE CONTROL (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) .

Is any other DTC displayed?
- Yes : Perform the diagnosis according to DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>List of Diagnostic Trouble Code (DTC) .
- No : Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.