Vacuum Line Malfunction
Table of contents
P1437 TOYOTA Possible Causes
- Defective vacuum hose or line
- Defective HCAC VSV
- Defective vacuum sensor
- Defective check valve
How do I fix code P1437 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.
Cost of diagnosing the P1437 TOYOTA code
The cost of diagnosing the P1437 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)
P1437 TOYOTA Description
Before the engine is started, by-pass valve is open. When the engine starts, the Engine Control Module (ECM) delivers an output signal to HCAC VSV. HCAC VSV opens, allowing the vacuum to be applied to the actuator, which causes the by-pass valve to close. When the by-pass valve closes, exhaust gases pass into the HC absorber where the gases are stored until the temperature of the front TWC increases. This prevents hydrocarbons from being delivered from the vehicle when TWC temperature is low. After TWC becomes warm, the HCAC VSV closes and the vacuum to the by-pass valve is shut off, causing the 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 absorber is warm to scavenge the hydrocarbons that remain in the HC absorber. DTC is set if an abnormality exists in the engine vacuum for the HCAC system.