Honda Civic/Acura Integra

since 1994 of release

Repair and car operation

Check of serviceability of a condition and replacement of the oxygen sensor (l-probe)

Located in a final collector of the engine the l-probe traces the content of oxygen in a stream of the fulfilled gases. At contact of molecules О2 to a sensitive element of a probe the sensor develops a peak signal in a range from 0.1 to 0.9 In, depending on concentration of oxygen. And, to value 0.1 In there corresponds high contents О2 (the grown poor mix), and to value 0.9 In – low (the enriched mix). ESM/RSM continuously supervises a signal arriving from the oxygen sensor, in case of need giving out commands for correction of structure of an air and fuel mix at the expense of change of duration of opening of injectors of injection. The optimum ratio of components of the gas mixture, guaranteeing the minimum fuel consumption at the most effective functioning of the catalytic converter, makes 14.7 parts of air on 1 part of fuel, – its module of management and tries to support constantly, being guided by information arriving from a l-probe.

It should be noted that the oxygen sensor is capable to develop alarm tension only being heated-up to normal working temperature (near 320°С). While the sensor is in cold condition ESM/RSM works in a mode of the OPENED CONTOUR.

If at heated-up to normal working temperature and/or the engine working during not less than two minutes the oxygen sensor develops a stable signal amplitude 0.45 In (at turns not below 1500 in a minute), the system of self-diagnostics brings in memory ESM/RSM the corresponding code of malfunction (see. Check of serviceability of a condition and replacement of the sensor of VMT/provision of cranked shaft/position of pistons in cylinders of the engine (TDC/CKP/CYP)). The code is brought also in case of detection of malfunction in a chain of a heater of the sensor.

In case of violation of serviceability of functioning of a l-probe or its chain ESM/RSM passes to a mode of the opened contour, ignoring information arriving from the sensor and supporting structure of an air and fuel mix at some set level providing sufficient efficiency of return of the engine.

Serviceability of functioning of the oxygen sensor depends on performance of set of some certain conditions:

   a) Electric parameters: Stability of a peak signal of a low voltage developed by the sensor in big degree depends on quality of contact connections of a chain of a l-probe which should be checked first of all in case of problems;
   b) Supply of external air: The design of a l-probe provides free circulation of external air in the sensor. At probe installation always check passableness of air channels;
   c) Working temperature: ESM/RSM starts to react to information arriving from a l-probe only after the sensor will be heated-up to normal working temperature (near 320°С). it is necessary not to lose sight of this fact at check of serviceability of functioning of a probe;
   d) Quality of fuel: Serviceable functioning of a l-probe becomes possible only under condition of application for filling of the car of UNLEADED fuel!

In addition to the conditions listed in the previous paragraph at service of a l-probe it is necessary to observe some special precautionary measures:

   a) The oxygen sensor is equipped tightly built in in it and the equipped contact tip with a piece of the electroconducting which attempts of a detachment can lead to an irreversible exit of the sensor out of operation;
   b) Try not to allow hits in a jalousie of the sensor or its electric socket of dirt and greasing;
   c) Do not use for cleaning of the oxygen sensor any solvents;
   d) Address with a l-probe extremely carefully, do not drop it and try not to shake;
   e) The silicone protective cover should put on on the sensor strictly definitely not to be melted and not to break serviceability of functioning of a probe.

Check

PERFORMANCE ORDER

1. Find the electric socket of the sensor. From a reverse side of the socket enter the unbent writing paper clip into a nest of contact of an alarm wire (white or white-red) (see an accompanying illustration). Identification of contact plugs of the socket can be made by means of schemes of electric connections (see. Head Onboard electric equipment). Connect to a paper clip positive щуп the voltmeter, a negative conclusion earth. Colors of isolation of electroconducting of a l-probe are given also in schemes of electric connections (see. Head Onboard electric equipment). 2. Watch measuring instrument indications (мВ) in the course of an engine warming up. 3. At the initial stage the cold sensor should develop a constant signal amplitude 0.1÷0.2 In (a mode of the opened contour). About two minutes later the engine will reach normal working temperature and the indication of the sensor will start to hesitate in limits from 0.1 to 0.9 In (a mode of the closed contour). If the system does not pass to a mode of the closed contour, or passes with is inadmissible a big delay (the lazy sensor), replace a l-probe. 4. Check also serviceability of functioning of a heater of the oxygen sensor. Disunite the socket of electroconducting of a probe and connect an ohmmeter between heater plugs (see schemes of electric connections in Head Onboard electric equipment of the real Management). Nominal resistance makes 10÷40 Ohm. 5. Check serviceability of giving of a food on a heater. Disunite the electric socket and measure tension on it from a plait (again address to schemes of electric connections). At the included ignition (do not start the engine) the voltmeter should fix tension of the battery. If a food is absent, check an electroconducting condition on a chain site between the main relay, ESM/RSM and the oxygen sensor. 6. At negative results listed above checks, replace a l-probe.

Replacement

PERFORMANCE ORDER

The l-probe reversing on the cold engine can appear the extremely inconvenient in view of thermal compression of metal final collectors/pipes of system of release. In order to avoid risk of damage of components before starting removal of the sensor warm up the engine during few minutes – try not to burn about the warmed-up surfaces in the course of procedure performance. 1. Disconnect a negative wire from the battery. To Poddomkratta the car also establish it on props. If the stereosystem established on the car is equipped with a security code before disconnecting the battery make sure that have the correct combination for audiosystem input in action! 2. Disunite the socket of electroconducting of the oxygen sensor. 3. Accurately turn out a probe from a final collector (see an accompanying illustration). 4. Before a sensor vvorachivaniye into place grease its carving part with anti-taking hermetic (new sensors are usually already covered with the relevant structure). 5. Screw the sensor on the regular place and strongly tighten it. 6. Connect electroconducting. 7. Lower the car on the earth and make its trial runs. Check memory of the module of management on existence of codes of malfunctions.