Engine Controls - System/component Tests: Other Suzuki X-90 I

POWERTRAIN CONTROL MODULE (PCM)

Note. For identification of PCM harness connectors and wire terminals, see PIN VOLTAGE CHARTS article.

PCM LOCATION

PCM Power Circuits

Turn ignition on. Check for battery voltage between ground and indicated PCM connector terminals. See PCM POWER & GROUND CIRCUITS table. If battery voltage is not indicated, ensure fuses are not blown. Check main relay operation. See RELAYS & SOLENOIDS .

PCM Ground Circuits

Disconnect PCM connector. Check continuity between ground and indicated PCM connector terminals. See PCM POWER & GROUND CIRCUITS table. If continuity does not exist, repair appropriate wire between PCM connector and ground.

PCM POWER & GROUND CIRCUITS

PCM Circuit Resistance

Perform circuit resistance tests with PCM harness connectors disconnected. See CIRCUIT RESISTANCE CHARTS .

CAMSHAFT POSITION (CMP) SENSOR

For testing procedures, see DTC P0340 in TESTS W/CODES article.

CAMSHAFT POSITION (CMP) SENSOR VOLTAGE (1)

CRANKSHAFT POSITION (CKP) SENSOR

1. Check for correct CKP sensor installation. Inspect CKP sensor for damage or foreign material attached to sensor magnet. Repair as necessary.
2. Disconnect CKP sensor harness connector. Using an ohmmeter, measure resistance between terminals of sensor. See the «CRANKSHAFT POSITION (CKP) SENSOR RESISTANCE»(ref-26265-S06119368422001010500000) table. If resistance is not as specified, replace CKP sensor.

CRANKSHAFT POSITION (CKP) SENSOR RESISTANCE @ 68°F (20°C)

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Remove sensor from intake manifold and place in water with a thermometer. Heat water to specified temperature and check resistance. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE table. Replace sensor if resistance is not within specification.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR RESISTANCE

FUEL TANK PRESSURE SENSOR

Remove tank pressure sensor. Connect three 1.5 volt batteries in series. Connect positive terminal to "Vin" terminal of tank pressure sensor. (Scheme 26) Connect negative terminal to "Ground" terminal. Using a voltmeter, measure voltage between terminals "Vout" and "Ground". Connect a hand-held vacuum pump to tank pressure sensor. As vacuum is applied, voltage reading should decrease. Refer to the FUEL TANK PRESSURE SENSOR VOLTAGE table. If reading is not as specified, replace tank pressure sensor.

Scheme 26

FUEL TANK PRESSURE SENSOR VOLTAGE

HEATED OXYGEN SENSOR (HO2S) NO. 1

1. Start engine and allow it to reach normal operating temperature. Pull back seal at HO2S No. 1 connector. Using a voltmeter, backprobe HO2S No. 1 connector between sensor signal and sensor ground terminals. (Scheme 27)
2. Increase engine speed to 2000 RPM and hold for about one minute while observing voltmeter. Reading should fluctuate between zero and one volt, without being constantly high or low. If voltage is not as specified, see DTC P0131-P0134 in «TESTS W/CODES»(ref-26219) article.

HEATED OXYGEN SENSOR (HO2S) NO. 2

1. Start engine and allow it to reach normal operating temperature. Pull back seal at HO2S No. 2 connector. Using a voltmeter, backprobe HO2S No. 2 connector between sensor signal and sensor ground terminals. (Scheme 27)
2. Increase engine speed to 2000 RPM and hold for about one minute while observing voltmeter. Reading should be far less active than HO2S No. 1. If voltage is not as specified, see DTC P0136 and P0420 in «TESTS W/CODES»(ref-26219) article. Heated Oxygen Sensor (HO2S) Heaters No. 1 & 2 - Turn ignition off. Disconnect HO2S No. 1 or 2 pigtail connector. Using an ohmmeter, measure resistance between VB and GND terminals. (Scheme 27) See the «HO2S HEATER RESISTANCE»(ref-26265-S11450797862001010500000) table. Replace HO2S if resistance is not as specified.

HO2S HEATER RESISTANCE @ 68°F (20°C)

Scheme 27

INTAKE AIR TEMPERATURE (IAT) SENSOR

1. Disconnect IAT sensor connector. Turn ignition on. Check voltage between ground and Red/Black wire terminal of connector. If voltage is not 4-5 volts, check wiring harness for an open or short. If voltage is 4-5 volts, go to next step.
2. Remove IAT sensor and place in container of water with a thermometer. Heat water to specified temperature and check resistance. See «INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE»(ref-26265-S29051151442001010500000) table. Replace IAT sensor if resistance is not within specification.

INTAKE AIR TEMPERATURE (IAT) SENSOR RESISTANCE

MANIFOLD ABSOLUTE PRESSURE (MAP)/MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR

1. To test MAP sensor on vehicle, turn ignition on. Connect scan tool to Data Link Connector (DLC). Connect a hand-held vacuum pump to MAP sensor. Observe scan tool display as specified vacuum is applied. See «MAP SENSOR OUTPUT SIGNAL TABLE (ON-VEHICLE)»(ref-26265-S09619119662001010500000) .
2. If scan tool reading is not within specification, see DTC P1408 in «TESTS W/CODES»(ref-26219) article. To bench test pressure sensor, see «MAP SENSOR OUTPUT VOLTAGE TABLE (OFF-VEHICLE)»(ref-26265-S40049778622001010500000) . If voltage is not within specification, replace MAP sensor.

MAP SENSOR OUTPUT SIGNAL (ON-VEHICLE)

MAP SENSOR OUTPUT VOLTAGE (OFF-VEHICLE)

MASS AIRFLOW (MAF) SENSOR

1. Without disconnecting MAF sensor connector, move connector seal for access to terminals. Turn ignition on. Using a voltmeter, backprobe between Blue/Black wire and Black/Orange wire terminals of connector.
2. If battery voltage is present, go to next step. If battery voltage is not present, check continuity of Blue/Black wire, Black/Orange wire and Gray/Yellow wire circuits between PCM and MAF sensor connector.
3. Measure voltage between Blue/Black wire and Gray/Black wire terminals of MAF sensor connector. If voltage is not 1.0-1.6 volts, check continuity of Blue/Black wire and Gray/Black wire circuits between PCM and MAF sensor connector.
4. Start engine. MAF sensor voltage signal should increase as engine RPM increases. If MAF sensor does not test as described, check MAF sensor connections. If connections are okay, replace MAF sensor.

POWER STEERING PRESSURE (PSP) SWITCH

1. Start engine. Using a voltmeter, measure voltage (backprobe) between ground and specified PCM harness connector terminal with steering wheel in specified position. Refer to the «PSP SWITCH VOLTAGE»(ref-26265-S30339964942001010500000) table. If reading is as specified, signal circuit is okay. If reading is not as specified, go to next step. PSP SWITCH VOLTAGE Application PCM Connector/Terminal No. Volts With 3-Speed A/T Or M/T Straight C/19 10-14 Turned To Stop C/19 0-1 With 4-Speed A/T Straight D/16 10-14 Turned To Stop D/16 0-1
2. Turn ignition off. Disconnect wire connector from PSP switch on power steering pump. Turn ignition on. Measure voltage between ground and PSP switch signal wire at connector. If reading is 10-14 volts, replace PSP switch. If reading is not as specified, check for an open or short to ground in signal wire. Repair as necessary. If wire is okay, replace PCM. Retest system.

THROTTLE POSITION (TP) SENSOR

1. Disconnect negative battery cable and TP sensor connector. (Scheme 28) Using an ohmmeter, check resistance between indicated terminals. See «THROTTLE POSITION (TP) SENSOR RESISTANCE»(ref-26265-S23213878922001010500000) table.
2. If resistance is not as specified, adjust TP sensor. See the «ADJUSTMENTS»(ref-26178) article. If resistance is not as specified after adjustment, replace TP sensor. For further diagnostic procedures, see «TESTS W/CODES»(ref-26219) article.

THROTTLE POSITION (TP) SENSOR RESISTANCE

Scheme 28

TRANSMISSION RANGE SENSOR (TRS)

Disconnect negative battery cable. Disconnect harness connector at TRS on side of transmission. (Scheme 29) Using an ohmmeter, ensure continuity exists between indicated sensor terminals in specified gear range. See TRANSMISSION RANGE SENSOR RESISTANCE table. Ensure continuity does not exist between specified terminals and ground. Replace TRS if it does not test as specified.

TRANSMISSION RANGE SENSOR RESISTANCE

Scheme 29

1. Disconnect negative battery cable. Remove instrument cluster. Connect ohmmeter between VSS and GND terminals on back of instrument cluster. Insert screwdriver into speedometer cable connector. Rotate screwdriver. (Scheme 30)
2. Ohmmeter reading should alternate between zero and infinity 4 times for each revolution of speedometer head. Replace speedometer if VSS does not test as described.

Scheme 30

Fuel Pump Relay

1. Turn ignition off. Disconnect negative battery cable. Disconnect relay connector and remove relay. Refer to the «FUEL PUMP RELAY LOCATION»(ref-26265-S26098188192001010500000) table. Using an ohmmeter, check continuity between terminals No. 2 and 4. (Scheme 31)or (Scheme 32). If continuity is not present, go to next step. If continuity is present, replace relay.
2. Check resistance between terminals No. 1 and 3. If resistance is 61-75 ohms, go to next step. If resistance is not as specified, replace relay.
3. Energize relay by applying battery voltage and ground to terminals No. 1 and 3. Check continuity between terminals No. 2 and 4. If continuity is present, relay is okay. If continuity is not present, replace relay.

Scheme 31

Scheme 32

FUEL PUMP RELAY LOCATION

Main Relay

1. Disconnect negative battery cable. Remove main relay. Main relay is located under instrument panel, attached to side of heater case. Using an ohmmeter, measure resistance between terminals No. 2 and 4. (Scheme 31)or (Scheme 32).
2. Continuity should not be present. If continuity is present, replace relay. Measure resistance between terminals No. 1 and 3. On models produced in Japan, resistance should be 61-75 ohms. On models produced in Canada, resistance should be 79-95 ohms. If resistance is not as specified, replace relay. Apply battery voltage and ground to terminals No. 2 and 4. Continuity should now be present between terminals No. 1 and 3. If continuity is not present, replace relay.

EGR Solenoid Vacuum Valve

See DTC P0400 in TESTS W/CODES article.

Canister Purge Valve

See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.

Idle Air Control (IAC) Valve

See IDLE AIR CONTROL (IAC) VALVE under IDLE CONTROL SYSTEM.

See RELAYS under RELAYS & SOLENOIDS.

Note. For fuel system pressure testing and specifications, see BASIC TESTING article. For diagnosis of a no-start or rough running condition related to a fuel system problem, see CIRCUIT TESTS in BASIC TESTING article.

Fuel Pressure Regulator

1. Regulator is mounted on end of fuel rail. Start engine and let idle. Disconnect vacuum hose from regulator. If vacuum is present, go to next step. If no vacuum is present, check for blocked hose between regulator and intake manifold.
2. Check fuel pressure with engine running and vacuum hose connected to regulator. Disconnect vacuum hose from fuel pressure regulator. If fuel pressure does not increase, replace fuel pressure regulator.

Fuel Pump

See CIRCUIT TESTS in BASIC TESTING article.

Fuel Injector(s)

See CIRCUIT TESTS in BASIC TESTING article.

Note. For PCM harness connector and wire terminal identification, see PIN VOLTAGE CHARTS article.

FAST IDLE AIR (FIA) VALVE

1. Fast idle air valve is bolted to throttle body. To check valve, ensure engine is cool. Turn ignition off. Disconnect Idle Air Control (IAC) valve harness connector. Start engine and ensure idle speed reduces gradually as engine coolant temperature rises. If operation is as specified, FIA valve is okay. If operation is not as specified, go to next step.
2. Remove valve from throttle body. Inspect throttle body for clogged air and water passages. Repair as necessary. Immerse valve in water. When water temperature is less than 158°F (70°C), valve should be open. When water temperature is greater than 158°F (70°C), valve should be closed. Replace FIA valve if operation is not as specified. Install a NEW gasket when installing valve.

1. Check idle speed following procedures in «ADJUSTMENTS»(ref-26178) article. If idle speed is as specified, go to next step. If idle speed is not as specified, follow procedures in DTC P0505 in «TESTS W/CODES»(ref-26219) article.
2. With engine running, turn headlights on. If idle remains at specified idle speed, system is okay. If idle speed is not within specification, go to next step.
3. Turn ignition off. Disconnect IAC valve hose from air intake pipe. Turn ignition on. Blow through end of hose and ensure air does not pass through valve. Turn ignition off. On models with 3-speed automatic or manual transmission, connect a fused jumper wire (backprobe) between PCM harness connector "B", terminal No. 12, (Light Green/Black wire) to ground. On models with 4-speed automatic transmission, connect a fused jumper wire (backprobe) between PCM harness connector "A", terminal No. 12, (Light Green/Black wire) to ground. Turn ignition on. Blow through end of hose and ensure air passes through valve. If operation is not as specified, go to next step. If operation is as specified, replace PCM. Retest system.
4. Turn ignition off. Disconnect IAC valve harness connector. Using an ohmmeter, measure resistance between terminals of IAC valve. If resistance is 11-14 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace IAC valve. Retest system.
5. Blow into disconnected IAC valve hose. Ensure air does not pass through. Using fused jumper wires, connect battery voltage and ground to IAC valve terminals. Air should now pass through valve. Replace IAC valve if operation is not as specified. If IAC valve is okay, check IAC valve harness for open or short. Repair as necessary.

ISC DUTY SPECIFICATION

Note. DO NOT remove ISC actuator from throttle body; it is adjusted by manufacturer.

Idle Switch (Inside ISC Actuator)

Turn ignition off. Using a voltmeter, backprobe between ground and PCM harness connector "B", terminal No. 4. Turn ignition on. With throttle lever in contact with ISC plunger, reading should be 0-1 volt. With throttle lever away from ISC plunger, reading should be 4-6 volts. If either voltage reading is not within specification, replace lower throttle body.

ISC Actuator

1. Disconnect ISC actuator connector. Using an ohmmeter, ensure continuity exists between ISC actuator terminals No. 1 (Gray/Red wire) and No. 3 (Gray wire).
2. Using four 1.5-volt batteries (6 volts) in series, connect batteries to ISC actuator terminals No. 1 and 3. DO NOT connect batteries for more than one second.
3. With positive side of batteries connected to ISC actuator terminal No. 3, ensure actuator extends. With positive side of batteries connected to ISC actuator terminal No. 1 (leads reversed), ensure actuator retracts. If any of ISC actuator tests fail, replace lower throttle body.

ISC Actuator Relay

Disconnect negative battery cable. Remove ISC actuator relay from relay box. ISC actuator relay testing is the same as main relay testing. For testing, see RELAYS under RELAYS & SOLENOIDS.

TIMING CONTROL SYSTEMS

Note. Ensure increasing engine speed advances ignition timing.

1. Ensure transmission is in Neutral or Park. Set parking brake. Inspect crankshaft pulley timing mark and timing mark indicator on timing belt cover. Clean marks as required. Start engine and allow it to reach normal operating temperature. Turn all accessories off. Attach timing light to No. 1 spark plug wire. Ensure idle speed is correct. See «ADJUSTMENTS»(ref-26178) article. CAUTION: Driving vehicle with jumper wire installed in test connector will damage catalytic converter.
2. Using a fused jumper wire, connect terminals "D" (ground) and "E" (test switch) of test connector. See «ADJUSTMENTS»(ref-26178) article. Aim timing light at timing cover timing marks. If ignition timing is not within specification, loosen distributor hold-down bolt and rotate distributor to obtain correct ignition timing. See IGNITION TIMING table in «ADJUSTMENTS»(ref-26178) article. Tighten distributor hold-down bolt and recheck ignition timing. See «ADJUSTMENTS»(ref-26178) article. NOTE: With jumper wire installed, timing should be fixed. if timing varies, terminal "D" is not properly grounded.
3. Remove jumper wire from test connector. Ensure ignition timing advances with engine speed (RPM). If ignition timing does not advance, check CTP switch, test switch terminal circuit and PCM.

EXHAUST GAS RECIRCULATION (EGR)

Note. Vehicle speed input must be received by PCM for proper EGR operation. While testing EGR, leave transmission in Neutral with engine running. Block one rear wheel and rotate other rear wheel forward by hand.

EGR Valve

1. Disconnect EGR vacuum hose and attach a hand-held vacuum pump to vacuum hose port. Apply about 8 in. Hg to EGR valve while checking for smooth operation of diaphragm. Ensure diaphragm maintains position without losing vacuum.
2. With engine at idle, apply vacuum to EGR diaphragm. Engine should idle rough or stall. If diaphragm retracts and engine RPM does not change, remove EGR valve and check for clogged passages.

EGR Pressure Transducer

1. For EGR pressure transducer location, see appropriate vacuum diagram in «VACUUM DIAGRAMS»(ref-26218) article. Remove upper cap from pressure transducer. Remove filter and clean with compressed air. Reinstall filter and upper cap. Remove EGR pressure transducer.
2. Using low air pressure, apply air to one vacuum hose port and plug opposite vacuum hose port. Air should flow freely through filter housing.
3. Connect a hand-held vacuum pump to one vacuum hose port. Connect vacuum gauge to opposite vacuum hose port. Using low air pressure, apply air to bottom port while applying vacuum with vacuum pump. Vacuum should be indicated on gauge and should hold. When low air pressure is removed from bottom port, vacuum gauge indicator should return to zero. Replace EGR pressure transducer if operation is not as specified.

1. Turn ignition off. Disconnect EVAP canister purge valve harness connector located on intake plenum chamber. Using an ohmmeter, measure resistance of purge valve. If resistance is 28-36 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace EVAP canister purge valve. Retest system.
2. Blow into port "A" of purge valve. (Scheme 33) Air should not flow through port "B". Using fused jumper wires, connect a 12-volt battery to EVAP canister purge valve terminals. Blow into hose "A". Air should pass through port "B". If operation is as specified, check EVAP canister purge valve harness for open or short. Repair as necessary. If operation is not as specified, replace EVAP canister purge valve. Retest system.

Scheme 33

POSITIVE CRANKCASE VENTILATION (PCV)

1. Disconnect PCV valve with hose. Start engine and let idle. Place a finger over end of PCV valve and check for vacuum. If vacuum is present, go to next step. If vacuum is not present, check for clogged valve. Replace if necessary.
2. Turn engine off. Remove PCV valve from hose. Shake valve and listen for rattle. Replace PCV valve if no rattle is heard.

TRANSMISSION

Note. Although Torque Converter Clutch (TCC) relay is not technically an engine performance system, it can affect driveability if it malfunctions.