Pressure Regulator Check (S/C to +12V)

DTC P0748
Pressure regulator check (S/C to +12V).

Possible causes by suggested order of priority:
^ C193/53 (OLG) shorted to +12V.
^ ECU fault.

C193/53 (OLG) Shorted to +12V.
CHECK THE FOLLOWING:
^ C193/53 (OLG) shorted to +12V.
^ Disconnect EAT C193 before measuring voltage between C193/53 (OLG) and vehicle earth.
ACCEPTABLE RESULTS
^ Between 0.0 V and 4.0 V.
DIAGNOSTIC HINTS
^ If the voltage is above the acceptable range check the harness connected to C193/53 (OLG) for short circuit to +12V.

ECU Fault.
CHECK THE FOLLOWING:
^ Ensure that the check for short to +12V has been carried out.
^ Check transmission ECU by substitution with a known good unit.
POSSIBLE FAULTS
^ Faulty transmission ECU.