Code No. P0048: Variable Geometry Control Solenoid Valve Circuit High Input

OPERATION

• Power is supplied to the variable geometry control solenoid valve connector terminal from the engine control relay connector terminal.
  
• The engine-ECU connector terminal VGT makes the power transistor in the unit be in "ON" position, and that makes currents go on the variable geometry control solenoid valve connector terminal.
  

FUNCTION

• The variable geometry control solenoid valve controls the vacuum pressure introduced into the variable geometry actuator, using the signal from the engine-ECU. This allows the boost pressure to be adequate for the driving conditions.
  

TROUBLE JUDGMENT

• Battery positive voltage is 8 - 16 V.
  
• 2 seconds later after the engine has started up.
  

• Variable geometry control solenoid valve output voltage is 4.5 V or more (driving current is abnormally high).
  

FAIL-SAFE AND BACKUP FUNCTION

• The fuel injection amount is restricted (Output restriction).
  
• The open angle of the accelerator pedal is restricted.
  
• The throttle valve is opened (Electrical discontinuity).
  
• The EGR control is stopped (fully closed).
  
• The DPF regeneration is prohibited.
  
• The turbocharger control is prohibited.
  
• The AS&G control is prohibited.
  

PROBABLE CAUSES

• Short circuit in variable geometry control solenoid valve circuit or loose connector contact
  
• Failed engine-ECU
  

	Go to Step 2.

	Repair or replace the connector, or repair the damaged harness wire.

	Replace the engine-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).