Engine Controls - System/component Tests: Other Honda Civic V

Ground Circuits

1. Using an ohmmeter, check for continuity to ground on appropriate ECU ground terminals. See «POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION»(ref-15662-S10684378952001010800000) table. (Scheme 8) Resistance should be zero ohms for each circuit. If reading is not zero ohms, repair open to ground.
2. Using a DVOM, touch negative lead of voltmeter to a good ground. Touch positive lead of voltmeter to each ground terminal. With vehicle running, voltmeter should indicate less than.1 volt. If voltmeter reading is greater than.1 volt, check for open, corrosion or loose connection on ground lead.

Scheme 8

1. Using a voltmeter, check for battery voltage between ECU power terminal and ground. See «POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION»(ref-15662-S10684378952001010800000) table. (Scheme 8) If battery voltage is not present, check appropriate ECU fuse in underhood fuse box. See «ECU POWER CIRCUITS FUSE IDENTIFICATION»(ref-15662-S19724766202001010800000) table. If fuse is okay, check for an open in wire between underhood fuse box and appropriate ECU power circuit terminal.
2. Turn ignition switch to ON position. Using a voltmeter, check for battery voltage between appropriate ECU power circuit terminal and ground. See «POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION»(ref-15662-S10684378952001010800000) table. (Scheme 8) If battery voltage is not present, check appropriate fuse in underhood fuse box. See «ECU POWER CIRCUITS FUSE IDENTIFICATION»(ref-15662-S19724766202001010800000) table. If fuse is okay, check for an open in wire between fuse box and appropriate ECU power circuit terminal or check for a defective ignition switch. POWER & GROUND CIRCUITS TERMINAL IDENTIFICATION Application (1) ECU Terminal Ground Circuits A2, A4, A16 & A18 Power Circuits Ignition Switch In OFF Position B1 ON Position A13 & A15 (1) (Scheme 8)for terminal location identification. ECU POWER CIRCUITS FUSE IDENTIFICATION Application (1) Fuse Ignition Switch In OFF Position HAZARD ON Position ECU (1) All fuses are in underhood fuse box.

ENGINE SENSORS & SWITCHES

Note. Some test procedures require using a test harness when testing certain components or systems. Use PGM-FI Test Harness (07999-PD6000A ). (Scheme 9) Test harness must be connected between control unit and main wire harness connectors.

Scheme 9

ATMOSPHERIC PRESSURE (PA) SENSOR

Connect test harness between ECU and wiring harness connectors. (Scheme 9) Turn ignition switch to ON position. Measure voltage between test harness terminals C9 (positive) and C12 (negative). (Scheme 8) If voltage is approximately 3.0 volts, PA sensor is okay. If voltage is not within specification, check wiring. If wiring is okay, replace sensor.

OXYGEN (O2) SENSOR

1. Disconnect O2 sensor from wire harness connector. Start engine, and bring to normal operating temperature. Backprobe sensor connector, and measure voltage between O2 sensor and ground.
2. While observing voltage, open throttle fully, and then release suddenly. Voltage should be greater than 0.6 volt at wide open throttle and less than 0.4 volt when throttle is quickly released. If voltage readings are not as specified, check wiring to sensor. If wiring is okay, replace O2 sensor.

Scheme 10

1. Ensure ignition is off. Disconnect 6-pin connector from TDC/CRANK sensor. Measure resistance between sensor terminals D and E and terminals B and C. (Scheme 10) If resistance is 350-550 ohms, go to next step. If resistance is not as specified, replace distributor assembly.
2. Check for continuity between body ground and each terminal individually (B, C, D and E). If continuity exists on any terminal, replace distributor assembly.

Scheme 11

1. Disconnect 8-pin connector from TDC/CRANK/CYL sensor. Measure resistance between sensor terminals C and D and between terminals A and B. (Scheme 11) If resistance readings are 350-550 ohms for each pair, go to next step. If resistance readings are not as specified, replace distributor assembly.
2. Check for continuity between each terminal and chassis ground. If continuity exists on any terminal, replace distributor assembly.

Electronic Air Control Valve (EACV)

See IDLE CONTROL SYSTEM .

EGR Control Solenoid Valve

See EMISSION SYSTEMS & SUB-SYSTEMS .

Fast Idle Control Solenoid (1.6L)

See IDLE CONTROL SYSTEM .

Purge Cut-Off Solenoid Valve

See EMISSION SYSTEMS & SUB-SYSTEMS .

Tandem Valve Control Solenoid (1.5L TBI)

See AIR INDUCTION SYSTEMS .

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING article.

Fuel Injector(s)

Disconnect 2-pin connector at injector. Using an ohmmeter, measure resistance between injector terminals. Resistance reading should be as specified. See FUEL INJECTOR RESISTANCE TEST table. If resistance reading is not as specified, replace injector(s).

FUEL INJECTOR RESISTANCE TEST

Fuel Injector Resistor

Disconnect injector resistor harness connector. Check resistance between each injector resistor terminal (B, C, D and E) and power terminal (A). (Scheme 12) Resistance reading should be 5-7 ohms for each pair of terminals. If any resistance reading is not as specified, replace injector resistor.

Scheme 12

Scheme 13

1. Turn ignition off. Disconnect main relay harness connector. Check for continuity between connector terminal No. 2 and chassis ground. (Scheme 13) If continuity exists, go to next step. If continuity does not exist, repair open in Black wire from No. 2 terminal. See «WIRING DIAGRAMS»(ref-15664) article.
2. Using a voltmeter, measure voltage between connector terminals No. 1 (positive) and No. 2 (negative). (Scheme 13) If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between battery and main relay as well as EFI/ECU fuse on Civic or ECU fuse on CRX in underhood relay box. Repair as required.
3. Turn on ignition. Measure voltage between connector terminals No. 5 (positive) and No. 2 (negative). (Scheme 13) If battery voltage exists, go to next step. If battery voltage does not exist, check wiring from ignition switch and main relay. Check fuse No. 12 in dash fuse box and wiring from fuse box to main relay. Repair or replace as necessary.
4. Connect voltmeter to connector terminals No. 4 (positive) and No. 2 (negative). (Scheme 13) Turn ignition switch to START position. If battery voltage is present, go to next step. If specified voltage is not present, check wiring between ignition switch and main relay. Check fuse No. 1 (A/T) or fuse No. 3 (M/T). Check wiring from fuse box to main relay. Repair or replace as necessary.
5. Connect a jumper wire between connector terminals No. 5 and No. 7. (Scheme 13) Turn on ignition. Fuel pump should operate. If fuel pump fails to operate, check fuel pump wiring.

Electric Load Detector

1. Connect ECU test harness between ECU and main harness connector. (Scheme 9) Turn ignition on. Using a voltmeter, measure voltage between test harness terminals B19 (+) and A18 (-). (Scheme 8)
2. Turn headlight switch to first position. Voltmeter should read 2.5-3.5 volts. Turn headlight switch to second position. Voltmeter should read 1.5-2.5 volts. If voltage reading is not as specified, replace electric load detector.

1. With ignition off, disconnect 2-pin EACV connector. Using an ohmmeter, measure resistance between EACV terminals. If resistance reading is 8-15 ohms, go to next step. If resistance is not as specified, replace EACV.
2. Check for continuity between each EACV terminal and chassis ground. If continuity is present on any terminal, replace EACV.

1. Disconnect 2-pin connector at fast idle control solenoid valve. Disconnect upper vacuum hose from fast idle control solenoid valve, and connect vacuum gauge to valve.
2. Start engine. While observing vacuum gauge, use jumper wires to energize fast idle control solenoid by connecting battery voltage to Black/Yellow wire and grounding Blue wire of solenoid valve. If gauge does not read manifold vacuum, replace fast idle control solenoid valve.

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING article in the ENGINE PERFORMANCE Section.

Scheme 14

1. Start engine, and bring to full operating temperature. Disconnect vacuum hose from EGR valve, and connect a vacuum gauge. If vacuum does not exist, go to step 2). If vacuum is present, inspect EGR system hose routing. Check for short in Red wire between ECU and EGR control solenoid valve. If hose routing and wire are okay, replace solenoid valve.
2. Turn off ignition. Disconnect 4-pin connector from control box. Using jumper wires, connect battery voltage to connector terminal D and ground connector terminal C. (Scheme 14) Start engine, and observe vacuum gauge. If gauge does not read approximately 8 in. Hg, go to next step. If specified vacuum does register, solenoid valve is okay.
3. Remove control box cover. Disconnect lower hose on EGR control solenoid valve, and connect a vacuum gauge to hose. If gauge reads 8 in. Hg, replace EGR control solenoid valve. If specified vacuum does not register on gauge, check vacuum hose routing to CVC valve. If hose routing is okay, replace CVC valve.

EGR Valve

1. Ensure all connectors between EGR valve lift sensor and ECU are securely connected. Warm engine to full operating temperature.
2. Disconnect vacuum hose from EGR valve. Connect a vacuum pump to EGR valve, and apply vacuum. EGR valve should hold vacuum and engine should die once vacuum is applied. If results are not as specified, replace EGR valve.

Scheme 15

1. Connect EGR Valve Lift Sensor Test Harness (07GMJ-ML80100 ) between EGR valve lift sensor and engine wire harness. (Scheme 15) Turn on ignition. Using a voltmeter, measure voltage between Red (positive) terminal and Green (negative) terminal.
2. If voltage reading is approximately 5 volts, go to next step. If voltage is not as specified, repair open in Yellow/White wire and/or Green/White wire between EGR valve and ECU.
3. Measure voltage between White (positive) terminal and Green (negative) terminal. If voltage reading is approximately 1.0 volts, go to next step. If voltage is not as specified, check for short in White/Black or Yellow wires between ECU and EGR valve lift sensor. If wiring is okay, replace EGR valve.
4. Disconnect vacuum hose from EGR valve, and connect vacuum pump to EGR valve. While observing voltmeter, slowly apply 8 in. Hg to EGR valve. If voltage increases smoothly from 1.0-4.0 volts as vacuum is applied to EGR valve, EGR valve lift sensor is okay. If voltage does not increase smoothly, replace EGR valve.

1. Disconnect vacuum hose from purge control diaphragm valve located on charcoal canister. Connect a vacuum gauge to hose. Start engine, and allow to idle. Engine coolant temperature must be below specified value. See «PURGE CONTROL TEST TEMPERATURE»(ref-15662-S37984466272001010800000) table. PURGE CONTROL TEST TEMPERATURE Application Maximum Temperature - °F (°C) 1.5L TBI 176 (80) 1.5L PFI 104 (40) 1.6L 135 (57)
2. If vacuum is not present, go to step 4). If vacuum is present, disconnect 2-pin or 4-pin harness connector at purge cut-off solenoid valve. See «PURGE CUT-OFF SOLENOID CONNECTOR IDENTIFICATION»(ref-15662-S21430090722001010800000) table. Using a voltmeter, measure voltage between specified wires. PURGE CUT-OFF SOLENOID CONNECTOR IDENTIFICATION Application Connector Type Positive Terminal Wire Color Negative Terminal Wire Color 1.5L PFI 4-Pin Black/Yellow Green 1.5L TBI 2-Pin Black/Yellow Green 1.6L 2-Pin Green Black
3. If battery voltage exists, inspect vacuum hose for leaks, blockage and incorrect routing. If hose is okay, replace purge cut-off solenoid valve. If voltage does not exist, measure voltage between positive terminal and chassis ground. If battery voltage does not exist, repair open circuit in appropriate positive wire. If voltage exists, check for open circuit between negative terminal and ECU. If wire is okay, replace ECU.
4. Warm engine to full operating temperature (cooling fan comes on). Turn off engine, and restart. If vacuum now exists, proceed to «CHARCOAL CANISTER»(ref-15662-S37065358332001010800000) . If vacuum is not present, disconnect 2-pin or 4-pin harness connector at purge cut-off solenoid valve. See «PURGE CUT-OFF SOLENOID CONNECTOR IDENTIFICATION»(ref-15662-S21430090722001010800000) table.
5. If vacuum now exists, check for short circuit in negative wire between harness connector and ECU. If wire is okay, substitute known good ECU, and retest. If system now operates properly, replace ECU. If vacuum still does not exist, check vacuum hose for leaks, blockage and improper routing. If hose is okay, replace purge cut-off solenoid valve.

Charcoal Canister

Connect vacuum gauge to canister purge air hose, located at bottom of canister. (Scheme 16) Start engine, and increase engine speed to 3500 RPM. Vacuum should register on gauge within one minute. If results are not as specified, inspect purge hose for blockage. If hose is okay, replace charcoal canister.

Scheme 16

2-Way Valve

1. Remove fuel filler cap. Remove vapor hose from fuel tank side of 2-way valve, and install "T" fitting. Connect vacuum gauge to "T" fitting and a vacuum pump to end of hose.
2. Slowly apply vacuum while watching vacuum gauge. Vacuum reading should stabilize momentarily at 0.2-0.6 in. Hg. If reading is as specified, go to next step. If vacuum stabilizes (valve opens) at less than 0.2 in Hg or greater than 0.6 in. Hg, replace 2-way valve, and retest.
3. Move vacuum hose from vacuum to pressure fitting side of vacuum pump. Slowly pressurize vapor line while watching gauge. If pressure stabilizes at 0.4-1.4 in. Hg, valve is okay. If pressure stabilizes at less than 0.4 in. Hg or greater than 1.4 in. Hg, replace 2-way valve, and retest.

POSITIVE CRANKCASE VENTILATION (PCV)

Check crankcase ventilation hoses and connections for leaks and clogging. Start engine. With engine at idle, pinch and release PCV hose. Clicking noise should be heard. If no clicking noise is heard, verify if manifold vacuum is present. If manifold vacuum is present, replace PCV valve, and recheck.

Throttle Control Dashpot

1. Start engine, and warm to full operating temperature. Disconnect vacuum hose from throttle control dashpot diaphragm, and check engine speed.
2. Engine speed should be 2000-3000 RPM. If engine speed is excessively high, adjust engine speed by bending tab on throttle shaft linkage. If engine speed does not change after bending tab, connect vacuum gauge to throttle control dashpot diaphragm vacuum hose, and check vacuum. Vacuum should be present.
3. If vacuum is present, replace throttle control dashpot diaphragm, and retest. If vacuum is not present, check dashpot diaphragm vacuum hose for improper connection, cracks and blockage. If necessary, check and replace vacuum "T" fitting (if equipped).
4. Reconnect throttle control dashpot vacuum hose, and check idle speed. Idle speed should be as specified. See «SPECIFICATIONS»(ref-15653) article in the ENGINE PERFORMANCE Section.