Description and Diagnosis Procedure

SYSTEM: VSV for Fuel Pressure Control Circuit (California Only)

CIRCUIT DESCRIPTION






The ECM turns on a vacuum switching valve (VSV) to draw the air into the diaphragm chamber of the fuel pressure regulator if it detects that the temperature of the engine coolant is too high during engine starting. The air drawn into the chamber increases the fuel pressure to prevent fuel vapor lock at high engine temperature in order to help the engine start when it is warm.
Fuel pressure control ends approximately 90 seconds after the engine is started.

DIAGNOSTIC PROCEDURE
1. Check VSV for fuel pressure control.
- If OK proceed to step 2.
- If not OK replace VSV.
2. Check voltage of VSV power source.
- If not OK proceed to step 3.
- If OK proceed to "Diagnosis By Symptom".
3. Check for open and short in harness and connector between "EFI Main" relay and ECM.
- If OK check and replace ECM.
- If not OK repair or replace harness or connector