Engine Controls - System/component Tests - 2.6L: Other Honda Passport I

Ground Circuits

Using a DVOM, touch negative voltmeter lead to a good ground. Touch positive voltmeter lead to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If reading is greater than one volt, check for open, corrosion and loose connection on ground lead. See ECM GROUND LOCATION for ECM ground location.

ECM GROUND LOCATION

Power Circuits (Constant Voltage)

1. ECM should always have constant battery voltage to retain memory. Check voltage at Red/White wire of 22-pin ECM connector. Voltage is supplied by fuse No. 3, located in fuse block at left side of dash.

Power Circuits (Ignition Voltage)

1. ECM should always have battery voltage when ignition is on. Check voltage at Light Green/Red and Red wires of 26-pin ECM connector. Voltage is supplied by ECM relay, located in fuse/relay box at right side of engine compartment. White/Blue wire of main relay receives voltage from fuse No. 1 in fuse/relay box at right corner of engine compartment. Purple or Violet wire of main relay receives voltage from fuse No. 8, located in fuse block at left side of dash.

AIRFLOW SENSOR

Note. Airflow sensor malfunctions may set Code 61 or 62. For additional information, see TESTS W/CODES - 2.6L article.

Scheme 98

1. Pull back rubber boot on airflow sensor harness connector. With ignition off, check for voltage between Violet wire terminal and ground. Voltage should be less than.2 volt. If voltage is incorrect, check wiring to ECM. Repair as necessary.
2. Turn ignition on. With engine off, check voltage between Red wire and ground. Voltage should be 10-14 volts. With ignition off, voltage should be less than.2 volt. If voltage is incorrect, check wiring to ECM. Repair as necessary.
3. With engine idling, check voltage between White wire and ground. Voltage should be 0.5-2.0 volts. If voltage is incorrect and voltage insteps 1) and 2) was okay, replace airflow sensor.
4. Check airflow sensor by-pass circuit. (Scheme 98) If circuit t is dirty or contaminated, clean with carburetor cleaner. DO NOT let carburetor cleaner touch electrical or rubber components.

COOLANT TEMPERATURE SENSOR

Note. Coolant temperature sensor malfunctions may set Code 14 or 15. For additional information, see TESTS W/CODES - 2.6L article.

1. Unplug coolant temperature sensor. Sensor is located on right side of engine, below intake manifold. Sensor connector contains Black and Green/Yellow wires.
2. Check resistance between sensor terminals at specified temperature. See «COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS»(ref-15976-S26287152532000122900000) . Replace sensor if it is not within specification.

COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS

CRANKSHAFT POSITION SENSOR

Note. Crankshaft position sensor malfunctions may set Code 41. For additional testing, see TESTS W/CODES - 2.6L article.

If crankshaft position sensor malfunctions, Code 41 will set. See TESTS W/CODES - 2.6L article. Replace distributor assembly if wiring circuit is okay.

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

Note. A malfunctioning MAP sensor may set Code 33 or 34. For additional testing, see TESTS W/CODES - 2.6L article.

1. Sensor is located on right side of engine compartment. Start engine, and warm to normal operating temperature. Ensure engine is idling. Disconnect and plug MAP sensor vacuum hose to VSV.
2. Using Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, connect DVOM (on voltmeter scale) to Green/Orange wire and Blue/White wire at back of MAP sensor connector. Voltage should indicate more than 2.5 volts. Unplug and reconnect MAP sensor vacuum hose. Voltage should indicate less than 2.5 volts. If voltage is not as indicated, replace MAP sensor.

MANIFOLD AIR TEMPERATURE (MAT) SENSOR

Note. Malfunctioning MAT sensor may set Code 23A or 23B. For additional testing, see TESTS W/CODES - 2.6L article.

OXYGEN SENSOR (O2S)

Note. Malfunctioning O2S may set Code 13, 44 or 45. For additional testing, see TESTS W/CODES - 2.6L article.

1. Start engine, and warm it to operating temperature. Ensure vehicle is operating in closed loop. Unplug oxygen sensor connector at sensor. Using Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, connect DVOM (on voltmeter scale) between ground and oxygen sensor connector (sensor side).
2. Place a short jumper wire in sensor lead (computer side). While holding jumper wire in one hand, alternately touch negative battery terminal and then positive battery terminal with other hand. DO NOT touch sensor lead directly to battery.
3. Monitor DVOM reading. When negative battery terminal is touched, oxygen sensor output voltage should increase (up to one volt). When positive battery terminal is touched, oxygen sensor output voltage should drop (as low as .1 volt). If oxygen sensor does not respond as indicated, replace sensor.

PARK/NEUTRAL SWITCH

Disconnect switch connector at transmission. Note terminal identification. (Scheme 99) Using ohmmeter, check continuity between specified terminals in proper gear positions. See PARK/NEUTRAL SWITCH CONTINUITY SPECIFICATIONS. Replace switch if continuity is not as specified.

PARK/NEUTRAL SWITCH CONTINUITY SPECIFICATIONS

Scheme 99

Scheme 100

1. Disconnect throttle valve switch. Note terminal identification. (Scheme 100) Check throttle valve switch terminals for p roper continuity. With throttle at idle, continuity should exist between terminals "I" and "P", but not terminals "P" and "F."
2. At wide open throttle, continuity should exist between terminals "P" and "F", but not terminals "I" and "P." Continuity should not exist between terminals "I" and "P" or "P" and "F" with throttle between idle and wide open position. Replace throttle valve switch if defective.

VEHICLE SPEED SENSOR (VSS)

Note. Malfunctioning vehicle speed sensor may set Code 24 or 63. For additional testing, see TESTS W/CODES - 2.6L article.

Scheme 101

Scheme 102

1. Remove instrument cluster and combination meter from dash. Using ohmmeter, check continuity across VSS terminals. (Scheme 101)and (Scheme 102).
2. Rotate speedometer shaft slowly. Reading should alternate from continuity to an open circuit 4 times per revolution. Replace speedometer assembly if VSS is defective.

MODULES, MOTORS, RELAYS & SOLENOIDS

Note. For component locations (Scheme 103)- (Scheme 112).

Electronic Spark Control Module

See TIMING CONTROL SYSTEMS under IGNITION SYSTEM.

IAC Motor

This component is called Idle Air Control (IAC) valve. See IDLE CONTROL SYSTEM .

ECM Relay

1. Remove relay from connector. Test for continuity between terminals No. 1 and 5. (Scheme 103) Continuity should not exist.
2. Apply battery voltage between terminals No. 2 and 4. Test for continuity between terminals No. 1 and 5. Continuity should exist. Replace relay if defective.

Air Regulator Solenoid

See IDLE CONTROL SYSTEM .

Scheme 103

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING - 2.6L .

Pressure Regulator

1. Install fuel pressure gauge on fuel rail. Use care when installing fuel pressure gauge, as fuel lines are under pressure. Disconnect vacuum hose at pressure regulator.
2. Start engine and note fuel pressure. Ensure vacuum supply exists at vacuum line. Reconnect vacuum hose. Fuel pressure should decrease slightly. Replace regulator if pressure does not change.

Note. Malfunctioning pressure regulator VSV may set Code 25 or 53. For additional testing, see TESTS W/CODES - 2.6L article.

Pressure Regulator Vacuum Switching Valve (VSV)

1. VSV is located on right side of engine compartment, near battery. Pressure regulator VSV and canister purge VSV share a 4-pin electrical connector and are mounted side by side. Ensure VSV hoses are connected to pressure regulator.
2. Disconnect electrical connector. Connector contains Black/White and Light Green/Yellow wires. Wires for pressure regulator VSV are Blue and Black.
3. Using ohmmeter, check resistance between Blue and Black wire terminals of VSV. Replace VSV if resistance is not about 35 ohms. Reconnect connector.
4. To check VSV operation with engine off, disconnect electrical connector. Apply battery voltage to Blue wire, and connect ground wire to Black wire. Replace VSV if operation of vacuum ports does not change. WARNING: Use care when installing fuel pressure gauge, as fuel lines are under pressure.
5. To check VSV operation with engine running, install fuel pressure gauge on fuel rail. Start engine and note fuel pressure. Fuel pressure should be about 35 psi (2.5 kg/cm 2 ). Disconnect electrical connector from VSV.
6. Apply battery voltage to Blue wire, and connect ground wire to Black wire of VSV. Fuel pressure should be about 42 psi (2.9 kg/cm 2 ). Replace VSV if pressure does not increase.

Scheme 104

1. Fuel pump relay is located under hood on right inner fenderwell inside relay box. Remove relay from connector. Test for continuity between terminals No. 1 and 3. (Scheme 104) Continuity should not be present. Test for continuity between terminals No. 1 and 2. Continuity should be present.
2. Apply battery voltage between terminals No. 4 and 5. Continuity should exist between terminals No. 1 and 3. Continuity should not exist between terminals No. 1 and 2. Replace relay if defective.

FUEL CONTROL

Note. Throttle valve switch and throttle position sensor are mounted on throttle body throttle shaft. M/T models use throttle valve switch. A/T models use throttle position sensor and throttle valve switch.

Note. Fuel cut-off and fuel injection reactivation is controlled by throttle valve switch. See FUEL-CUT SPECIFICATIONS for fuel-cut operating conditions.

Scheme 105

1. Warm engine to operating temperature. Turn ignition off. Unplug throttle valve switch wire connector. Insert a fine wire into upper (idle) terminal. Reconnect throttle valve switch connector with fine wire partially pulled outward. (Scheme 105)
2. Start engine, and operate it at 2000-2500 RPM. Connect battery voltage to fine wire installed on throttle valve switch. When battery voltage is applied, engine speed should decrease to about 1250 RPM. Engine surging may occur, which is normal during test procedure. FUEL-CUT SPECIFICATIONS Test Condition Speed (MPH) Engine (RPM) Idle Contact Fuel-Cut 15 or More 1700 or More On Fuel-Cut 0 1700 or More On Injection 6 or Less 1250 or Less Off

Fuel Injectors

1. Unplug fuel injector harness at injector. Using ohmmeter, measure resistance across terminals. Replace fuel injectors if resistance is not within specification. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(ref-15976-S34801007282000122900000) .
2. With engine running, check fuel injector operating noise. Normal operation of injectors is indicated if a regular click is heard, which varies with engine speed. If click is not heard, replace injector. FUEL INJECTOR RESISTANCE SPECIFICATIONS Application Ohms 2.6L 13.8 NOTE: FUEL INJECTOR BALANCE TEST is also known as CHART C-2A. CAUTION: To prevent flooding, entire test should not be repeated more than once.

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING - 2.6L article.

TIMING CONTROL SYSTEMS

Note. If problem develops with ESC, ECM will set Code 43. For additional testing, see TESTS W/CODES - 2.6L article.

Air Management Valve

1. Warm engine to normal operating temperature. With engine idling, ensure secondary air is passing from silencer on air management valve. (Scheme 106)
2. Stop engine. Disconnect air hose at check valve. Plug opening of check valve. Start engine and note air passage from air management valve. After a few seconds, air should pass from silencer. Replace air management valve if defective. Air management valve will operate only under specified conditions. (Scheme 107)

Check Valve

Remove check valve from air manifold. Blow air into air pump side of check valve. Air should pass freely to manifold side of check valve. Blow air into manifold side of check valve. Air should not pass to air pump side of valve. Replace check valve if defective.

Scheme 106

Scheme 107

Duty Solenoid

Apply battery voltage to duty solenoid terminals, and air should flow without restriction between ports "X" and "Y". (Scheme 108) Disconnect battery voltage from terminals and air should not flow through ports. Replace duty solenoid if defective.

Scheme 108

Scheme 109

Scheme 110

1. System will operate only under specified conditions. (Scheme 110) To test system operation, ensure engine coolant temperature is less than 59°F (15°C). Install tachometer. Disconnect vacuum hose at EGR valve, and connect vacuum gauge to vacuum hose.
2. Start engine. Vacuum gauge should read zero at all engine speeds. With engine at normal operating temperature, vacuum gauge should read zero at idle. Vacuum gauge should start to indicate vacuum at 3500 RPM. Reconnect vacuum hose to EGR valve. Ensure EGR valve diaphragm moves when engine is at 2000 RPM. NOTE: Ensure Code 32 or 34 is not stored before testing EGR system. See «TESTS W/CODES - 2.6L»(ref-15942) article.

EGR Vacuum Switching Valve

Apply 12 volts to Vacuum Switching Valve (VSV) terminals. (Scheme 108) Air should flow freely through ports. Disconnect voltage. Air should not flow through ports. Replace VSV if defective.

EGR Valve

Using a vacuum pump, apply vacuum to EGR valve diaphragm. EGR valve diaphragm should hold vacuum. Ensure vacuum does not leak down and EGR valve diaphragm moves to a fully open position. Inspect EGR valve diaphragm for cracking. Check valve and seat for deformation and carbon deposits. Replace EGR valve if defective.

Scheme 111

EVAPORATIVE EMISSION SYSTEM (EVAP)

Note. Ensure evaporative system operating parameters are correct when testing EVAP system. (Scheme 112) Canister purge vacuum solenoid valve is also known as canister purge vacuum switching valve.

Scheme 112

Scheme 113

1. Disconnect canister purge Vacuum Switching Valve (VSV) harness connector, located on left fender panel, near canister. VSV harness connector wire colors are Green/White and Black/White or Light Green/Black. DO NOT confuse VSV connector with fuel pressure regulator connector.
2. Apply battery voltage to Blue wire terminal of VSV connector, and ground Black wire terminal. Ensure air does not flow freely between ports "Y" and "Z". Air should flow freely between ports "X" and "Y". (Scheme 113)
3. Disconnect battery voltage from VSV connector. Ensure air flows freely between ports "Y" and "Z". Air should not flow freely between ports "X" and "Y". If VSV does not perform as indicated, replace canister purge VSV.

Scheme 114

1. With engine off, disconnect vacuum hose from lower port "A". (Scheme 114) Connect a short section of hose to lower port "A", an d blow air into it. Ensure air does not flow freely into charcoal canister.
2. Connect hand-held vacuum pump to lower port "A", and apply 15 in. Hg. Purge control valve should hold vacuum. If it does not hold vacuum, replace purge control valve. With vacuum holding at port "A", install second hand-held vacuum pump to purge control valve port. Gradually apply vacuum to purge control valve port. Purge control valve should open at 7.1-8.7 in. Hg. Replace purge control valve if it does not perform as indicated.
3. Start engine, and let idle. Disconnect vacuum hose from port "C". Ensure vacuum is not present at ports "B" and "D". If vacuum is present at idle, check for improperly routed vacuum hoses or defective purge control valve.

PCV Valve

1. With engine running, remove PCV valve from rocker cover. Place thumb over end of valve to check for vacuum. If vacuum is present, go to step 3).
2. If no vacuum is present, remove PCV valve. If vacuum is present when valve is removed or engine dies, replace valve. If engine RPM changes little or does not change after removing valve from hose, replace vacuum hose between throttle body or intake manifold and PCV valve.
3. Turn ignition off. Remove PCV valve. Blow air into PCV valve from cylinder head side of valve. Ensure air flows through valve easily. DO NOT suck air through valve.
4. Blow air into intake manifold side of PCV valve. Ensure air does not flow through other side of valve. If valve does not function as indicated or valve does not rattle when shaken, replace PCV valve.

MISCELLANEOUS CONTROLS

Note. Although some controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.