POWERTRAIN CONTROL MODULE (PCM)
- Using a voltmeter, check for battery voltage at power terminals listed in table by application. Turn ignition on. Check for battery voltage at Ignition terminals. Turn ignition off. Using a voltmeter, check for battery voltage between power supply and Ground terminals. PCM/ECM POWER AND GROUND TERMINALS Model Connector No. Terminal No. 1996 - 1.6L DOHC Power 248 1 Ignition 248 12 Ground 249 1, 2, 14 1996 - 1.6L SOHC Power 248 1 Ignition 248 12 Ground 249 1, 2, 14, 15 1996 - 1.8L Power 249 5 Ignition 249 14, 26 Ground 249/254 1, 2, 15/8, 15 1997 - 1.6L Power 249 5 Ignition 249 14 Ground 249/254 1, 2, 15/1, 8 1997 - 1.8L Power 249 5, 8, 13 Ignition 249 14 Ground 248/249/254 1, 2/1, 2, 15/8
- If battery voltage is not present, check ENG fuse and FUEL INJ fuse in engine compartment fuse block. Replace fuse(s) as necessary and check for cause of blown fuse. If fuses are okay, check main relay. See «RELAYS»(ref-25100-S37839889582001010500000) under RELAYS & SOLENOIDS. If relay is okay, locate and repair open between main relay and PCM connector.
BRAKELIGHT SWITCH
Disconnect brakelight switch connector. Measure resistance between terminals of brakelight switch. With brake pedal released, continuity should not exist. With brake pedal depressed, continuity should be present. Replace switch as necessary.
CAMSHAFT POSITION SENSOR
Note. Turning ignition on with fuel injection connector connected will actuate injectors. Turning ignition on with 3-pin connector connected will actuate coil, causing sparks.
1.6L
Disconnect fuel injection connector. Disconnect ignition 3-pin connector. Remove distributor from head, leaving 6-pin connector attached. Turn ignition on. Check voltage at PCM connector C249 terminal No. 16 while turning distributor by hand. Voltage should be approximately 5 volts, with 4 pulses per revolution (SGT signal). Check voltage at PCM connector C249 terminal No. 4 while turning distributor by hand. Voltage should be approximately 5 volts, with one pulse per revolution (SGC signal). If voltage is not as specified, check wiring prior to replacing distributor.
1.8L
Disconnect fuel injection connector. Disconnect ignition 3-pin connector. Remove distributor from head, leaving 7-pin connector attached. Turn ignition on. Check voltage at PCM connector C249 terminal No. 16 while turning distributor by hand. Voltage should be approximately 5 volts, with 4 pulses per revolution (SGT signal). If voltage is not as specified, check wiring prior to replacing distributor.
CHASSIS ACCELERATION SENSOR
Chassis acceleration sensor is located on frame. Backprobe terminal No. 3 (Blue/Green wire) with ignition on. Check for voltage spike (less than one volt) while tapping sensor bracket. If no voltage spike is observed, replace sensor.
CRANKSHAFT POSITION SENSOR
Disconnect 3-pin crankshaft position sensor. Check resistance between terminals No. 1 and 2. Resistance should be 500-600 ohms at 68°F (20°C). If resistance is incorrect, replace sensor.
Check voltage at PCM connector C254 terminal No. 12 while applying vacuum to EGR boost sensor. See EGR BOOST SENSOR (1.8L) . If voltage is not as specified, repair wiring or replace sensor.
| Vacuum Applied (1) | (2) Volts At PCM |
|---|---|
| 4.4 (15) | .3 |
| 11.8 (40) | 1.6 |
| 28.1 (95) | 4.9 |
| 31.0 (105) | 4.9 |
| (1) In Hg (kPa). (2) Connector C254, terminal No. 15. | |
| (1) | In Hg (kPa). |
| (2) | Connector C254, terminal No. 15. |
EGR BOOST SENSOR (1.8L)
EGR POSITION SENSOR
- Disconnect EGR hose and EGR position sensor connector. Check resistance between sensor terminals No. 1 and 2. If resistance is 2700 ohms, go to next step. If resistance is not 2700 ohms, replace sensor.
- Connect EGR position sensor. Turn ignition on. Check voltage at PCM connector C254 terminal No. 13 while applying vacuum to EGR valve. See «EGR VALVE POSITION SENSOR»(ref-25100-S32577571042001010500000) . If voltage is not as specified, repair wiring or replace sensor.
| Vacuum Applied (1) | (2) Volts At PCM |
|---|---|
| 0 (0) | 0.8 |
| 5.0 (17) | 4.9 |
| (1) In Hg (kPa). (2) Connector C254, terminal No. 13. | |
| (1) | In Hg (kPa). |
| (2) | Connector C254, terminal No. 13. |
EGR VALVE POSITION SENSOR
EGR PRESSURE SENSOR
Turn ignition on. Check voltage at PCM connector C254 terminal No. 15 while applying vacuum to EGR pressure sensor. See EGR PRESSURE SENSOR (1.6L) . If voltage is not as specified, repair wiring or replace sensor.
| Vacuum Applied (1) | (2) Volts At PCM |
|---|---|
| 6.0 (20) | 3.5 |
| 12.5 (42) | 2.5 |
| 16.0 (54) | 2.0 |
| 25.0 (84) | .5 |
| (1) In Hg (kPa). (2) Connector C254, terminal No. 15. | |
| (1) | In Hg (kPa). |
| (2) | Connector C254, terminal No. 15. |
EGR PRESSURE SENSOR (1.6L)
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
Remove ECT sensor. Place sensor and thermometer in container of water. Connect ohmmeter between sensor terminals. Slowly heat water. Note resistance at specified temperatures. See ECT SENSOR RESISTANCE . Replace sensor as necessary.
| Temperature - °F (°C) | Ohms |
|---|---|
| 176 (80) | 290-350 |
| 68 (20) | 2200-2700 |
| 4 (-20) | 14,600-17,800 |
ECT SENSOR RESISTANCE
INTAKE AIR TEMPERATURE (IAT) SENSOR
IAT sensor is located inside of Mass Airflow (MAF) sensor. Disconnect MAF sensor connector. Measure resistance between terminals No. 3 (Brown/Black wire) and No. 4 (Black/Yellow wire) at MAF sensor. See INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE . If resistance is not as specified, replace MAF sensor.
| Temperature | Ohms |
|---|---|
| 68°F (20°C) | 2210-2690 |
INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE
MASS AIRFLOW (MAF) SENSOR
Remove Mass Airflow (MAF) sensor. Check MAF sensor for damage and replace sensor as necessary. Install MAF sensor and reconnect connector. Ensure engine is at normal operating temperature. Check voltage by backprobing specified terminal at MAF sensor connector. If voltage is not as specified, replace MAF sensor. See MASS AIRFLOW (MAF) SENSOR VOLTAGE .
| Terminal No. (Wire Color) (1) | Volts | |
|---|---|---|
| No. 2 (White/Orange wire) | ||
| Ignition On | Less than 1 | |
| At Idle | 1-2 | |
| No. 5 (Black/Yellow wire) | ||
| Ignition On | Less than 1 | |
| At Idle | Less than 1 | |
| (1) At normal operating temperature. | ||
| (1) | At normal operating temperature. |
MASS AIRFLOW (MAF) SENSOR VOLTAGE
PEDAL POSITION SWITCH
Disconnect CPP switch connector. Using ohmmeter, check continuity between switch terminals. With clutch pedal depressed, continuity should exist. With clutch pedal released, continuity should not exist. Replace switch as necessary.
1.6L & 1.8L
Disconnect NPS connector. Using ohmmeter, check continuity between switch terminals. Ensure continuity exists with transmission in Neutral. Continuity should not exist with transmission in any other gear. Replace switch as necessary.
HEATED OXYGEN SENSOR (HO2S)
- Ensure engine is at normal operating temperature. Disconnect HO2S connector. Connect voltmeter between ground and Red/Green wire at HO2S connector. Start engine and increase engine speed to 3000 RPM until voltmeter indicates .55 volt.
- Increase and decrease engine speed rapidly several times. When engine speed is increased, voltage should be .5-1.0 volt. When engine speed decreases, voltage should be 0-.5 volt. If voltage is not as specified, replace HO2S. If voltage is as specified, go to next step.
- Turn ignition off. Allow engine temperature to cool down. Using an ohmmeter, measure resistance between terminals No. 2 and 3 at HO2S connector. With HO2S temperature at 68°F (20°C), resistance should be about 13 ohms. If resistance is not as specified, replace HO2S.
Disconnect PSPS connector. Connect ohmmeter between ground and PSPS terminal. Start engine, and operate it at idle. Turn steering wheel from side to side, and observe ohmmeter. Ohmmeter should indicate continuity when front wheels are turned. Continuity should not exist when wheels are not turned. Replace switch as necessary.
THROTTLE POSITION (TP) SENSOR
See ADJUSTMENTS article for checking and adjustment procedures.
THROTTLE CLOSED POSITION SWITCH
See ADJUSTMENTS article for checking and adjustment procedures.
TRANSMISSION RANGE SENSOR
Transmission range sensor is located below battery, on transmission. Disconnect transmission range sensor. Check continuity of transmission range sensor. See TRANSMISSION RANGE SENSOR. (Scheme 5) If sensor does not test as specified, adjust or repair as needed.
| Gear Position | Continuity Between Terminals No. |
|---|---|
| Park | 1 & 5, 6 & 9 |
| Reverse | 2 & 5 |
| Neutral | 15 & 7, 6 & 9 |
| Drive | 4 & 5 |
| Second | 5 & 8 |
| First | 3 & 5 |
TRANSMISSION RANGE SENSOR
Scheme 5
- VSS is mounted on transaxle. Raise and support vehicle. Turn ignition on. Check voltage by backprobing VSS connector C150 terminal No. 1 while an assistant spins one drive wheel with other wheel blocked from turning. If voltage toggles between 1 and 10 volts, VSS is okay. If VSS does not function as specified, replace VSS.
RELAYS
Locate fuel pump relay below center of instrument panel in front of center console, on PCM mounting bolt. Main relay is located in engine compartment fuse/relay box. Remove relay. Check relay according to application.
Main Relay
- Check for continuity between terminals No. 2 and 4 at relay. If continuity does not exist, go to next step. If continuity exists, replace relay.
- Connect a jumper wire between positive battery terminal and terminal No. 1 at relay. Connect another jumper wire between negative battery terminal and terminal No. 3 at relay.
- Recheck continuity between terminals No. 2 and 4 at relay. If continuity exists, relay is okay. Testing is complete. If continuity does not exist, replace relay.
Fuel Pump Relay
- Check for continuity between terminals No. 2 and 3 at relay. If continuity does not exist, go to next step. If continuity exists, replace relay.
- Connect a jumper wire between positive battery terminal and terminal No. 1 at relay. Connect another jumper wire between negative battery terminal and terminal No. 4 at relay.
- Recheck continuity between terminals No. 2 and 3 at relay. If continuity exists, relay is okay. Testing is complete. If continuity does not exist, replace relay.
EGR Solenoid Valve
Disconnect vacuum hose. Ensure no air flows through valve. If air flows through valve, replace valve. Disconnect EGR solenoid valve connector. Energize solenoid by applying 12 volts to terminal No. 2 and grounding terminal No. 1. Ensure air flows through valve. If no air flows through valve, replace valve.
Fuel Injectors
Using stethoscope, listen for normal clicking sound at each injector during idle and acceleration. If clicking sound is not heard, check injector wiring circuit, or main relay and circuit.
Fuel Injector Resistance
Disconnect fuel injector connector. Using ohmmeter, measure resistance between injector terminals. If resistance is not as specified, replace injector. See INJECTOR RESISTANCE .
| Application | Ohms |
|---|---|
| 1.6L & 1.8L | 12-16 |
INJECTOR RESISTANCE
Pressure Regulator Control Solenoid
Disconnect vacuum hose from pressure regulator control solenoid. Blow air through solenoid port "A". (Scheme 6) Ensure air flows through port "B". Disconnect solenoid valve connector. Connect 12 volts and ground to solenoid terminals. Blow air through solenoid port "A". Air should flow through valve air filter. Replace solenoid as necessary.
Purge Control Solenoid Valve
See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.
Scheme 6
FUEL DELIVERY
Note. For fuel system pressure testing, see BASIC TESTING article.
See RELAYS under RELAYS & SOLENOIDS.
See SOLENOIDS under RELAYS & SOLENOIDS.
See SOLENOIDS under RELAYS & SOLENOIDS.
Injector Fuel Leakage (1.6)
- Relieve fuel system pressure. See «BASIC TESTING»(ref-25093) article. Remove fuel rail with injectors. Using wire, secure injectors tightly onto delivery pipe. CAUTION: Ensure injectors are securely tied to fuel rail. If injectors are not properly secured to fuel rail, fuel may spray from loose connections.
- Turn ignition on for 10 seconds. Repeat 5-10 times to pressurize fuel rail. Tilt injectors about 60 degrees. Ensure no fuel leakage exists at injectors. After 2 minutes, a single drop of fuel is acceptable. If fuel leakage is present, replace faulty injector.
IDLE AIR CONTROL (IAC) VALVE
Turn ignition off. Disconnect IAC connector. Check resistance between terminals. (Scheme 7) If resistance is not 10.7-12.3 ohms at 68°F (20°C), replace valve.
Scheme 7
IGNITION SYSTEM
Note. For basic ignition checks, see BASIC TESTING article.
EGR Valve
Start engine and allow it to idle. Disconnect inlet vacuum hose to EGR valve. Connect a vacuum pump to EGR valve inlet port. Apply 2.6-4.9" Hg vacuum. If engine runs rough or stalls, EGR valve is functioning properly. If engine does not run rough or stall, EGR valve is defective or EGR passage is plugged. Repair as necessary.
EGR Control Solenoid
Disconnect vacuum hoses from EGR control solenoid. Attempt to blow air through solenoid. No air should pass. Using jumper wires, apply battery voltage to solenoid. Again, attempt to blow air through solenoid. Air should pass. If solenoid does not function as specified, replace solenoid.
Charcoal Canister
Check for loose, missing, cracked or broken connections and parts. Repair or replace as necessary. No liquid should exist in canister.
2-Way Check Valve (1.6L)
Remove check valve. Connect a vacuum pump to port "A" of check valve. (Scheme 8) Air should flow with about.29" Hg applied. Connect vacuum pump to port "B" of check valve. Air should also flow with about 1.73" Hg applied. There should be no flow without vacuum. Replace valve as necessary.
Scheme 8
2-Way Check Valve 1.8L
Remove check valve. Blow air into port "A". (Scheme 9) Air should flow out port "C". Blow air into port "C". Air should flow out port "B". If valve does not operate as specified, replace valve.
Scheme 9
Disconnect vacuum hoses from purge control solenoid valve. Ensure air does not flow through solenoid valve. Connect 12 volts to terminal No. 1 and ground terminal No. 2 of solenoid valve. (Scheme 10) Attempt to blow air through solenoid valve. Air should flow through valve. Replace valve as necessary.
Scheme 10
Rollover Valve
Information not available from manufacturer.
Separator
Separator is located under left rear wheel well (1.6L and 1.8L). Raise and support vehicle. Remove left rear wheel (1.6L and 1.8L). Check for loose, missing, cracked or broken connections and parts. Repair or replace as necessary. No liquid should exist in canister.