Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1995 Lexus LS 400FACTORY OEM SERVICE PROCEDURE
Fuel Pressure Regulator VSV Control Circuit
- Check fuel pressure regulator VSV. See FUEL PRESSURE REGULATOR VACUUM SWITCHING VALVE (VSV) . If VSV is okay, remove glove box. Turn ignition on. Leave harness connectors attached to ECM. Measure voltage between chassis ground and terminal No. 9 (Red/White wire) of ECM connector E12. To identify ECM connectors and terminals, see Figure.
- If battery voltage is present, VSV circuit is okay. If battery voltage is not present, check circuit between ECM and VSV, and between VSV and EFI main relay. If circuit is okay, replace ECM.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.