What Does code Mean?

OBD II fault password P1259 is a manufacturer particular code that is characterized by carmaker Honda together “VTEC system Circuit fault (Bank 1)”, and also is collection on these applications once the PCM (Powertrain regulate Module) detects a defect, malfunction, or failure in the electrical control/monitoring device of the VTEC mechanism on financial institution 1. Note that “Bank 1” describes the bank of cylinders that includes cylinder #1 on V-type engines.

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“VTECH” means Variable Valve Timing & Lift Electronic Control, and is the name given to the proprietary system Honda supplies to alter the lift and duration that the engine valves top top VTEC equipped engines.

The VTEC device uses 2 (or occasionally three) camshaft lobe file that can be selected hydraulically to rise the volumetric performance of the engine. As a helpful matter though, VTEC must not be confused with change Valve Timing systems that turn camshafts loved one to a reference point in order come either advancement or retard the valve timing.

In terms of operation, the VTEC mechanism most frequently uses 2 camshaft lobe file per set of valves. One profile is design to enhance power and also fuel economy at low engine speeds, while the other profile is designed to rise airflow, and also hence engine power at engine speeds above around 4000 RPM. In practice, the three equivalent valve lifters (aka, rocker arms) have the right to move independently of each other; at low engine speeds, 2 valve lifters operate the valves, while the 3rd rocker eight is merely complies with the electronic came lobe, but cannot activate the valves.

When conditions allow, frequently at high engine speeds above around 4000 RPM, the PCM opens up an oil control solenoid that permits pressurized engine oil come act on a slide locking pin the locks the 3 valve lifters together. This allows the (middle) high-lift video camer lobe to carry its motion to the 2 adjoining valve lifters via the locking pin, thereby raising both the lift and also duration of the valves. As soon as the engine rate drops below around 4000 RPM, the PCM gets rid of oil pressure from the locking pin, i m sorry disengages the center valve lifter from the adjoining lifters, and also the engine reverts to using the low-lift lifters.

In practice, the PCM uses input data native the engine rate sensor, throttle place sensor, devoted VTEC oil push switch, and also several various other sensors to determine the switching point between high and low elevator valve operation, an interpretation that the switching procedure does no require any kind of inputs native the driver, and is therefore fairly seamless.

It need to be noted though when that password P1259 specifically describes a trouble in the VTEC systems’ control/signal/monitoring circuit, some mechanical failure settings can contribute to this code being set and stored.

Where is the sensor located?

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The image above shows the ar of the VTEC oil control solenoid ~ above a Honda civic engine. However, the actual ar an illustration of VTEC oil regulate solenoids differ somewhat between Honda applications, for this reason consult the hands-on for the impacted application because that details top top the location of the solenoid, as well as the routing, color-coding, and duty of each cable in the oil control solenoid’s manage circuit. Fail to identify wires appropriately will result in a misdiagnosis, and also the possible unnecessary replacement of parts and also components.

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What space the common causes of password ?

As proclaimed elsewhere, password P1259 refers to an electrical issue in the VTEC manage system, and also all diagnostic measures for this code need to start through a thorough visual inspection that all linked wiring and connectors. Nonetheless, some other common causes of code P1259 might include the following-

Damaged, burnt, shorted, disconnected, and also corroded wiring and/or connectorsDefective VTEC oil manage solenoidDefective VTEC oil press switchLow engine oil levelDirty, degraded, or unsuitable engine oilFailed or failing PCM, but note that because this a rarely event, the fault need to be sought elsewhere before any type of control module is replaced

NOTE: if there space some exceptions, the general dominance is the if the code sets at, or just above idling speeds, the error is brought about by a general electric issue, if if the password sets above around 4000 RPM, the fault virtually invariably entails insufficient oil pressure, or a fail of the VTEC oil push sensor.