Bypass Valve Malfunction
Table of contents
P1436 TOYOTA Possible Causes
- Defective vacuum hose or line
- Defective actuator
- Defective by-pass valve
- Defective front exhaust pipe
How do I fix code P1436 TOYOTA?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- There is a Factory Service Bulletin for the following Toyota Models:
- 2001 Toyota Prius
- 2002 Toyota Prius
- 2001-2002 Toyota Prius Factory Service Bulletin OBDII Code P1436
Cost of diagnosing the P1436 TOYOTA code
The cost of diagnosing the P1436 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1436 TOYOTA Description
By-pass valve is used with the Hydrocarbon Adsorber Catalyst (HCAC) system. Before engine is started, by-pass valve is open. When engine starts, Engine Control Module (ECM) delivers an output signal to HCAC Vacuum Switching Valve (VSV). HCAC VSV opens, allowing vacuum to be applied to actuator which causes the by-pass valve to close. When by-pass valve closes, exhaust gases pass into the HC adsorber where the gases are stored until the temperature of front Three-Way Catalytic Converter (TWC) increases. This prevents hydrocarbons from being delivered from vehicle when TWC temperature is low. After TWC becomes warm, the HCAC VSV closes and vacuum to by-pass valve is shut off, causing by-pass valve open. When rear TWC becomes warm, exhaust emissions are cleaned by the TWC. The HCAC VSV may also be operated during a deceleration condition when HC adsorber is warm in order to scavenge the hydrocarbons that remain in the HC adsorber. DTC is set if by-pass valve does not operate properly.