Nissan Maxima QX

1. On models till 1998 issues are a part of the EGR system the EGR valve, the electromagnetic valve of management (EGRC) connected with depression in port and the pipeline, the sensor of temperature of EGR and the valve of the sensor of the counter-pressure (VRT). RSM operates functioning of system via the electromagnetic EGRC valve. The special gate located directly behind a butterfly valve is provided in the inlet air highway. Depression of inlet port is monitored via the gate located the throttle case. At acceleration the butterfly valve opens that leads to increase in depth of depression in the inlet pipeline.
2. The VRT valve switch traces depth of final counter-pressure at change of turns of the engine. Information arriving from EGR temperature sensor is used by RSM at management of a stream of recirculation of the fulfilled gases by inclusion/switching off of system.

1. Check all hoses for existence of cracks, twisting and other mechanical damages. Estimate tightness of nipple connections.

2. For check of serviceability of functioning of the EGR system warm up the engine up to the normal working temperature. Transfer transmission to neutral situation, cock the parking brake and prop up antiretractable boots back wheels of the car. Leave the engine working at single turns. Having opened a butterfly valve, lift the frequency of rotation of the engine to 2000 ÷ 4000 rpm, then again close the gate, - the rod of the EGR valve has to move at change of turns. Repeat check several times. If the rod does not move. Check serviceability of giving of a vacuum signal for the EGR valve. Disconnect a hose from the valve and, having pressed a finger to its cut, repeat the procedure. If depression in a hose is absent, make sure of tightness of the corresponding nipple connections, then you pass to check of the electromagnetic EGRC valve.

1. At the switched-off engine disconnect a vacuum hose and by means of the manual vacuum pump create depression about 25.4 mm Hg in depth on the EGR valve if the valve opens, measure its working course which has to make about 3 mm. Replace the faulty valve.
2. Again create depression and press a hose. The valve has to remain open within not less than 30 seconds, otherwise violation of tightness of a diaphragm takes place and assembly should be replaced.
3. Start the engine and create depression on the valve. At the open valve violation of stability of turns of idling has to take place, otherwise it is necessary to make sure of lack of violations of passability of channels in the inlet pipeline. If no changes of turns of the engine at opening closing of the valve happen, perhaps the last in general is jammed in any of provisions. Remove the EGR valve and check a plate and its saddle for existence of foreign deposits.
4. At a strong nagaroobrazovaniye the valve should be wiped with solvent, watching that it did not get to contact with a diaphragm.
5. By means of the manual vacuum pump fix the valve in open situation and carefully scratch out the layer of deposits softened by solvent from working surfaces of a plate and its saddle. Estimate degree of wear of working components, in case of need replace valvate assembly.

2. For check of serviceability of functioning of the electromagnetic EGRC valve disconnect from it an electrical wiring and, having grounded one plug, by means of a wire crossing point connect the second to a positive pole of the battery.
3. When giving food air has to be blown freely via two unions, nearby with each other. At power off the valve has to be blocked.

1. Disconnect an air inlet sleeve from the case of a throttle and assembly of the air cleaner (see the Head of the Power supply system and release).

2. Disconnect the vacuum line from the EGR valve. Give a nut of nipple connection.

3. Release fixing clamps.
4. Remove the EGR valve from the inlet pipeline. Old laying is not subject to reuse and at installation has to be replaced without fail.
5. A wire nozzle clear the surface of the inlet pipeline interfaced to the valve. If the valve is not replaced, smooth out also its interfaced surface. The screw-driver scratch out coal deposits.

In order to avoid damage of a diaphragm, do not wash out the valve in solvents at all! It is not recommended to resort to sandblasting of the interfaced surface also.

6. At an excessive nagaroobrazovaniye EGR channels can be cleaned by a wire brush. In order to avoid violation of passability of the valve track that all abrasive was carefully removed.
7. At strong pollution of the valve pick up EGR phone from a final collector and clean it from within. Remark: Remove the VRT valve switch and carefully remove an abrasive from all channels.
8. Installation is made upside-down.

1. Disconnect an electrical wiring from the electromagnetic valve of management of EGR (EGRC).
2. Carefully mark and disconnect all vacuum tubes.
3. Give a fixing nut and remove the electromagnetic valve.
4. Installation is made upside-down.

1. Disconnect an electrical wiring from the sensor and turn out the last from a tube.
2. Before installation grease a sensor carving with the anti-taking sealant.
3. Installation is made upside-down.

On models of 199 g of the issue the EGR system consists of the EGR valve arranged by the principle of the step motor, sensor of temperature of EGR and the module of management (RSM). RSM exercises control of a stream of recirculation of the fulfilled gases, opening and closing the EGR valve small steps. The system allows to carry out a thin dosage of a stream of EGR, trying to obtain the maximum return from the engine.

1. Check serviceability of giving of power supply for the EGR valve. Disconnect an electrical wiring and include ignition. ground the negative probe of the voltmeter on weight, positive connect to serially to plugs of two red wires of the socket. In both cases the measuring instrument has to register battery tension, otherwise it is necessary to check a condition of an electrical wiring on sites of a chain between the battery and the ECCS relay (do not forget about safety locks), both the relay and the EGR valve (see the scheme of electric connections at the end of the Head Onboard electric equipment).

2. By means of an ohmmeter measure resistance between the corresponding plugs of the socket of the EGR valve. At the room temperature (20 °C) the result of measurement has to make 22 Ohms, otherwise replace the valve. If the valve as it should be, the car it is necessary to drive away on car repair shop for a proyedeniye of diagnostics of RSM and performance of necessary recovery repair.

Remove EGR temperature sensor. Lower a working tip of the sensor in a container with water. Begin to warm up water, monitoring change of resistance of the sensor. In process of increase in temperature resistance has to fall and at 100 °C to reach value 10 ÷ 30 of kOhm.

1. Disconnect an air inlet sleeve from the case of a throttle and assembly of the air cleaner (see the Head of the Power supply system and release).
2. Take aside hoses and an electrical wiring for the purpose of ensuring access to the EGR valve.
3. Disconnect EGR tube.
4. Release fixing clamps.
5. Remove the EGR valve from the inlet pipeline. Old laying is not subject to reuse and at installation has to be replaced without fail.
6. By means of a scraper carefully smooth out the interfaced surfaces of the valve and the pipeline.
7. Installation is made upside-down.

1. Disconnect an electrical wiring from the sensor and turn out the last from the pipeline.
2. Before installation grease a sensor carving with the anti-taking sealant.
3. Installation is made upside-down.