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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 204 (Engine Controls - Self-Diagnostics - 1.8L - Ca) >> Diagnostic Tests >> DTC P0442: EVAP Control System >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ensure fuel cap is original equipment. Attempt to turn fuel cap clockwise. If fuel cap was tightened properly, go to next step. If fuel cap was not tightened properly, clean fuel cap and filler neck. Reinstall cap and retest system.
  2. While removing fuel cap, listen for air escaping from fuel tank. If air escaped from fuel tank, go to step  4 . If air did not escape from fuel tank, go to next step.
  3. Using a suitable hand vacuum/pressure pump with fuel cap adapter, apply pressure and vacuum to fuel cap. Fuel cap vacuum relief valve should open when pressure reaches 2.22-2.90 psi (15.3-20.0 kPa) and when vacuum reaches 0.98-1.78 in. Hg (3.3-6.0 kPa). If operation is as specified, go to next step. If operation is not as specified, replace fuel cap and retest system.
  4. Turn ignition off. Disconnect EVAP canister vent control valve harness connector. Disconnect vacuum cut valve by-pass valve harness connector. See Fig 2 . Connect a pressure pump to EVAP service port. See Fig 1 . Using fused jumper wires, apply battery voltage and ground between EVAP canister vent control valve terminal (component side). EVAP canister vent control valve should close. Using fused jumper wires, apply battery voltage and ground between vacuum cut valve by-pass valve terminal (component side). Vacuum cut valve by-pass valve should open. Apply 0.39-0.79 in. Hg (1.31-2.66 kPa) of pressure to EVAP system. Check EVAP system for leaks. If any leaks are found, repair as necessary and retest system. If no leaks are found, go to next step.
    5. CAUTION: DO NOT disassemble water separator.
  5. Remove water separator located on charcoal canister. Inspect water separator for cracks or blockage. With water separator port "A" plugged, blow air into port "B". See Fig 3 . Air should flow out of port "C". With port "C" plugged, blow air into port "B". Air should flow out of port "A". If operation is as specified, go to next step. If operation is not as specified, replace water separator and retest system.
  6. Reconnect all components. Check EVAP canister vent control valve, "O" ring and circuit. See DTC P0447: EVAP CANISTER VENT CONTROL VALVE  . If problem exists, repair as necessary and retest system. If problem does not exist, go to next step.
  7. Remove EVAP canister with EVAP vent control valve attached. Turn EVAP canister so EVAP vent control valve is pointing down. If water drains out, go to next step. If water does not drain out, go to step  9 .
  8. Weigh EVAP canister with EVAP vent control valve attached. Weight should be 4 lbs. (1.8 kg) or less. If weight is as specified, go to next step. If weight is not as specified, replace EVAP canister.
  9. Install components and reconnect all harness connectors. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect EVAP Canister Purge Volume Control Solenoid Valve (EVAP-CPVCSV) vacuum hose at EVAP service port. Start engine and let idle for at least 80 seconds. Increase engine speed to 2000 RPM while checking for vacuum at disconnected vacuum hose. If vacuum exists, go to step  12 . If vacuum does not exist, go to next step.
  10. Turn ignition off. Check for disconnected or damaged vacuum hoses between EVAP service port and EVAP-CPVCSV, and between EVAP-CPVCSV and intake manifold. See VACUUM DIAGRAMS article. If problem exists, repair as necessary and retest system. If problem does not exist, go to next step.
  11. Disconnect vacuum hoses from EVAP-CPVCSV. See Figure . Disconnect EVAP-CPVCSV harness connector. Apply air pressure to port "A" at EVAP-CPVCSV. See Fig 4 . Air should not flow from port "B". Using fused jumper wires, apply battery voltage and ground between EVAP-CPVCSV terminals (component side). Air should now flow from port "B". If EVAP-CPVCSV operates properly, go to next step. If EVAP-CPVCSV does not operate properly, replace EVAP-CPVCSV.
  12. Remove Manifold Absolute Pressure (MAP) sensor from its bracket and disconnect vacuum hose. For engine control components locations, see Figure - Figure . Turn ignition on. Using a DVOM, backprobe PCM harness connector and measure voltage between ground and terminal No. 91 (White wire) at PCM harness connector. See Figure and Figure . Voltage should be 1.8-4.8 volts. Using a hand vacuum pump, apply 7.87 in. Hg of vacuum to MAP sensor. Voltage should be 1.0-1.4 volts less than voltage measured with no vacuum applied. Voltage should decrease as vacuum is applied. If voltage is not as specified, replace MAP sensor. If voltage is as specified, go to next step.
  13. Remove fuel pump assembly from fuel tank. Fuel pump assembly is under back seat, under access plate. Measure resistance between terminals No. 3 and 4 at fuel pump assembly connector (component side). See Figure . Resistance should be 2300-2700 ohms at 68°F (20°C) and 790-900 ohms at 122°F (50°C). Resistance should decrease as temperature increases. See Figure . If resistance is not as specified, replace FTT sensor and retest system. If resistance is as specified, go to next step.
    14. CAUTION: DO NOT apply more than 5.91 in. Hg of vacuum to EVAP-CSPS. Replace EVAP-CSPS if it has been dropped from a height of more than 20" (0.5 m) onto a hard surface such as concrete.
  14. Remove EVAP Control System Pressure Sensor (EVAP-CSPS) with its harness connector connected. See Fig 2 . Turn ignition on. Using a vacuum pump, apply 2.76 in. Hg of vacuum to EVAP-CSPS vacuum port. Using a DVOM, backprobe ECM harness connector and measure voltage at terminal No. 84 (Pink wire) at PCM harness connector. See Figure . Voltage should be 0.4-0.6 volt. Disconnect vacuum pump. Voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP-CSPS and retest system.
  15. Check EVAP purge line for leaks. See VACUUM DIAGRAMS article. Repair as necessary and retest system. If purge line is okay, check On Board Refueling Vapor Recovery (ORVR) system. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. Repair as necessary and retest system. If ORVR system is okay, go to next step.
  16. Clean purge line with compressed air. Remove fuel pump assembly from fuel tank. Fuel pump assembly is under back seat, under access plate. Measure resistance between terminals No. 2 and 5 at fuel pump assembly connector (component side), with float rod in specified positions. See FUEL LEVEL SENSOR RESISTANCE  table. See Figure . If resistance is as specified, go to next step. If resistance is not as specified, replace fuel level sensor and retest system.
  17. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE  under SELF-DIAGNOSTIC SYSTEM.
FUEL LEVEL SENSOR RESISTANCE

Float Position Ohms
Full (1) 4-6
1/2 27-35
Empty (1) 78-85
(1) When float rod is in contact with stop.
Fig 1: Locating EVAP Service Port
G00015003Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Locating EVAP System Components (Under Rear Of Vehicle)
G00015004Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Testing Water Separator
G99H54806Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: Testing EVAP Canister Purge Volume Control Solenoid Valve
G98D01303Courtesy of NISSAN MOTOR CO., U.S.A.
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