Engine Controls - System & Component Testing Suzuki Grand Vitara I

INTRODUCTION

Before testing separate components or systems, perform procedures in BASIC DIAGNOSTIC PROCEDURES article. Since many computer-controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in appropriate SELF-DIAGNOSTICS article.

Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

POWERTRAIN CONTROL MODULE (PCM)

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

CAMSHAFT POSITION (CMP) SENSOR

For testing procedures, see DTC P0340 in appropriate SELF-DIAGNOSTICS article.

CAMSHAFT POSITION (CMP) SENSOR VOLTAGE

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 «CRANKSHAFT POSITION (CKP) SENSOR RESISTANCE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) 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. (Scheme 20) Replace sensor if resistance is not within specification.

Scheme 20

Scheme 21

1. Start engine and allow it to reach normal operating temperature. Pull back seal at HO2S No. 1 connector. Using DVOM, backprobe HO2S No. 1 connector between sensor signal and sensor ground terminals. (Scheme 21)
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-P0132 in appropriate SELF-DIAGNOSTICS 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 21)
2. Increase engine speed to 2000 RPM and hold for about one minute while observing voltmeter. Voltage readings should have slight fluctuations above and below.3 volts. If voltage is not as specified, see DTC P0136 and P0420 in appropriate SELF-DIAGNOSTICS 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 21) See HO2S HEATER RESISTANCE table. Replace HO2S if resistance is not as specified.

HO2S HEATER RESISTANCE @ 68°F (20°C)

INTAKE AIR TEMPERATURE (IAT) SENSOR

1. Disconnect IAT sensor connector. Turn ignition on. Check voltage between ground and Gray/Red wire (Esteem, Vitara 1.6L and 2.0L), Light Blue wire (Grand Vitara 2.5L) or Gray wire (Swift) terminal of connector. If voltage is not 4-6 volts (4.5-5.5 on Grand Vitara), check wiring harness for an open or short. If voltage is as specified, 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. (Scheme 22) Replace IAT sensor if resistance is not within specification.

Scheme 22

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR - ESTEEM & SWIFT

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 (ON-VEHICLE) - ESTEEM & SWIFT»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table. MAP SENSOR OUTPUT SIGNAL (ON-VEHICLE) - ESTEEM & SWIFT (1) Vacuum Applied (In. Hg) Scan Tool Display (kPa) 29.6 100 21.6 73 9.8 33 (1) With scan tool installed, ignition on, and specified vacuum applied to MAP sensor. CAUTION: Damage to MAP sensor will occur if connections are made incorrectly.
2. If scan tool reading is not within specification, see DTCs P0106, P0107 and P0108 in appropriate SELF-DIAGNOSTICS article. To bench test MAP sensor, see «MAP SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) - ESTEEM & SWIFT»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table. If voltage is not within specification, replace MAP sensor. MAP SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) - ESTEEM & SWIFT Altitude (Feet) Vacuum (In. Hg) (1) Output Voltage 0-2000 29.9-27.8 3.1-3.6 2001-5000 27.8-24.9 2.8-3.4 5001-8000 24.9-22.3 2.6-3.1 8001-10,000 22.3-20.7 2.4-2.9 (1) (Scheme 23)for proper test procedures.

Scheme 23

MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR - VITARA & GRAND VITARA

1. Remove MDP sensor from intake manifold. Inspect intake manifold vacuum passage, MDP sensor air vent hole and vacuum passage for clogs. Clean passages if necessary. Inspect sensor O-ring for damage and deterioration.
2. (Scheme 23)for MDP sensor testing procedure. See «MDP SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) - VITARA & GRAND VITARA»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table for voltage specifications. If voltage readings are not within specifications, replace MDP sensor and retest system.

MDP SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) - VITARA & GRAND VITARA

Vitara 1.6L & 2.0L

1. Disconnect MAF sensor connector. Turn ignition on. Using a DVOM, measure voltage between MAF sensor connector Blue/Black wire and ground. If battery voltage is indicated, go to next step. If battery voltage is not indicated, repair open or short circuit in Blue/Black wire between MAF sensor and main relay.
2. Turn ignition off and remove PCM cover. Reconnect MAF sensor. Turn ignition on and measure voltage (backprobe) at PCM connector terminal C51-3-10. Voltage reading should be 1.0-1.6 volts. Start engine. At idle, voltage should read between 1.7-2.0 volts. Voltage should stay below 5 volts but increase as engine speed is increased. If test results are not as specified, go to «DTC P0101: MASS AIRFLOW (MAF) CIRCUIT PERFORMANCE PROBLEM»(ref-91184-S28995036932002110600000) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - VITARA 1.6L & 2.0L article.

Grand Vitara 2.5L

1. Disconnect MAF sensor connector. Turn ignition on. Using a DVOM, measure voltage between MAF sensor connector Blue/Black wire and ground. If battery voltage is indicated, go to next step. If battery voltage is not indicated, repair open or short circuit in Blue/Black wire between MAF sensor and main relay.
2. Turn ignition off and remove PCM cover. Reconnect MAF sensor. Turn ignition on and measure voltage (backprobe) between PCM connector terminals No. B-20 and B-23. Voltage reading should be .5-1.0 volts. Start engine. At idle, voltage should read between 1.5-1.8 volts. Voltage should stay below 5 volts but increase as engine speed is increased. If test results are not as specified, go to «DTC P0101: MASS AIRFLOW (MAF) PERFORMANCE PROBLEM»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-self-diagnostics) under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - GRAND VITARA article.

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. See «PSP SWITCH VOLTAGE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table. If reading is as specified, signal circuit is okay. If reading is not as specified, go to next step. PSP SWITCH VOLTAGE Application/Wheel Position PCM Connector/Terminal No. (1) Volts Esteem & Swift Straight B/15 10-14 Turned To Stop B/15 0-1 Vitara 1.6L & 2.0L Straight C51-3-7 10-14 Turned To Stop C51-3-7 0-1 Grand Vitara 2.5L Straight A/26 10-14 Turned To Stop A/26 0-1 (1) For identification of PCM harness connectors and wire terminals, see PIN VOLTAGE/CIRCUIT RESISTANCE CHARTS article.
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.

Scheme 24

Scheme 25

1. Disconnect negative battery cable and TP sensor connector. (Scheme 24)or (Scheme 25). Using an ohmmeter, check resistance between indicated terminals. See «THROTTLE POSITION (TP) SENSOR RESISTANCE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table. THROTTLE POSITION (TP) SENSOR RESISTANCE (1) Application Ohms Esteem & Swift Between Terminals No. 1 & 2 2500-6000 Between Terminals No. 1 & 3 (2) (3) 100-20,000 Vitara 1.6L & 2.0L Between Terminals 1 & 3 4000-6000 Between Terminals 1 & 2 (2) 20-6000 Grand Vitara Between Terminals No. 1 & 3 4000-6000 Between Terminals No. 2 & 3 (2) 0-4600 (1) (Scheme 24)or (Scheme 25) for terminal identification. (2) Varies according to throttle position. (3) There should be more than 2000 ohms difference between idle and wide open throttle resistance.
2. On Grand Vitara 2.5L, if resistance is not as specified, adjust TP sensor. See «THROTTLE POSITION (TP) SENSOR - GRAND VITARA 2.5L V6»(/suzuki/grand-vitara/i-1997-2001/remont/adjustments/#engine-controls-on-vehicle-adjustments__grand-vitara-25l-v6) in ON-VEHICLE ADJUSTMENTS article. If resistance is not as specified after adjustment, replace TP sensor. For further diagnostic procedures, see appropriate SELF-DIAGNOSTICS article.

TRANSMISSION RANGE SENSOR (TRS)

Disconnect negative battery cable. Disconnect harness connector at TRS on side of transmission. Using an ohmmeter, ensure continuity exists between indicated sensor terminals in specified gear range. (Scheme 26)or (Scheme 27). See TRANSMISSION RANGE SENSOR RESISTANCE (ESTEEM & SWIFT) or TRANSMISSION RANGE SENSOR RESISTANCE (GRAND VITARA & VITARA) table. Ensure continuity does not exist between specified terminals and ground. Replace TRS if it does not test as specified.

Scheme 26

Scheme 27

TRANSMISSION RANGE SENSOR RESISTANCE (ESTEEM & SWIFT)

TRANSMISSION RANGE SENSOR RESISTANCE (GRAND VITARA & VITARA)

VEHICLE SPEED SENSOR (VSS)

Remove VSS from transaxle. Inspect VSS gear for damage or binding. Using an ohmmeter, measure resistance between sensor terminals. See VEHICLE SPEED SENSOR RESISTANCE table. Disconnect ohmmeter. Rotate VSS gear by hand. Magnetic pulse resistance should be felt as VSS is rotated. If operation is not as specified, replace VSS.

VEHICLE SPEED SENSOR RESISTANCE

Fuel Pump Relay/Main Relay

Note. Both fuel pump- and main relays are identical. Following test procedures apply to both.

1. Turn ignition off. Disconnect negative battery cable. Disconnect relay connector and remove relay. (Scheme 28)- (Scheme 31) for location. Using an ohmmeter, check continuity between terminals "A" and "B". (Scheme 32) If continuity is not present, go to next step. If continuity is present, replace relay.
2. Check resistance between terminals "C" and "D". If resistance is 70-110 ohms (79-95 on Vitara 1.6L and 2.0L), go to next step. If resistance is not as specified, replace relay.
3. Energize relay by applying battery voltage and ground to terminals "C" and "D". Check continuity between terminals "A" and "B". If continuity is present, relay is okay. If continuity is not present, replace relay.

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Evap 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.

Tank Pressure Control Solenoid Valve

See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.

Fuel Pump Relay

See RELAYS under RELAYS & SOLENOIDS.

Note. For fuel system pressure testing and specifications, see CIRCUIT TEST B-3: FUEL PRESSURE INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article. For diagnosis of a no-start or rough running condition related to a fuel system problem, see CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Pressure Regulator

Note. For additional fuel pressure regulator testing and specifications, see CIRCUIT TEST B-3: FUEL PRESSURE INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.

1. Fuel pressure 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 TEST B-2: FUEL PUMP CIRCUIT INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Injector(s)

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

See CIRCUIT TEST B-1: FUEL INJECTOR CIRCUIT INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.

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

Esteem & Swift

1. Remove throttle body from intake manifold. Remove IAC valve from throttle body. Reconnect all electrical connectors and have an assistant turn ignition on while IAC valve operation is observed. Valve should momentarily open and close, then stop in less than one second. Repeat test if necessary. If valve does not operate at all, follow test procedures in DTC P0505 in appropriate SELF-DIAGNOSTICS 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

Vitara

1. Remove IAC valve electrical connector. Using DVOM, check resistance of IAC valve between terminals No. 1 and 2, 2 and 3, 4 and 5, and 5 and 6. Resistance should be 35-43 ohms between each set of terminals. If resistance is as specified, go to next step. If resistance is not as specified, replace IAC valve and retest system.
2. Remove air cleaner hose and IAC valve. With electrical connector attached to IAC valve, crank engine for 2 seconds while observing valve. It should move once and then stop as soon as ignition is turned off. If IAC valve plunger does not move as specified, check for poor connections, open or short circuits in wiring. If electrical circuit is okay, replace IAC valve.

Grand Vitara

1. Remove IAC valve electrical connector. Using DVOM, check resistance of IAC valve between terminals "A" and "B", "B" and "C", "D" and "E", and "E" and "F". (Scheme 33) Resistance should be 20-24 ohms between each set of terminals at approximately 68° F (20° C). If resistance is as specified, go to next step. If resistance is not as specified, replace IAC valve and retest system.
2. Remove IAC valve from intake collector. With electrical connector attached to IAC valve, crank engine for 2 seconds while observing valve. It should move once and then stop as soon as ignition is turned off. If IAC valve plunger does not move as specified, check for poor connections, opens or shorts in wiring. If wiring is okay, replace IAC valve and retest system.

Scheme 33

TIMING CONTROL SYSTEMS

Note. Ensure ignition timing advances as engine speed is increased.

Ensure transmission is in Neutral or Park. Set parking brake. Start engine and allow it to reach normal operating temperature. Turn all accessories off. Ensure idle speed is correct. Inspect ignition timing. See IGNITION TIMING article.

Note. Ignition timing can only be adjusted on Vitara 2.0L and Grand Vitara 2.5L engines.

Ensure ignition timing advances with engine speed (RPM). If ignition timing does not advance, check CKP sensor, CKP signal rotor, TP sensor, test switch terminal circuit, VSS and timing belt cover installation.

EGR Valve

1. Connect scan tool to Data Link Connector (DLC). Start engine and warm up to operating temperature. With engine at idle, select MISC. TEST parameter on scan tool and operate EGR valve. If engine rpm drops, EGR valve is okay. Go to DTC P0400: EXHAUST GAS RECIRCULATION (EGR) FLOW MALFUNCTION in appropriate SELF-DIAGNOSTICS article if other EGR system problems are suspected. If engine rpm did not drop, go to next step.
2. Turn ignition off. Remove EGR valve and inspect EGR passages for clogs. Clean out passages as necessary. Using DVOM, inspect EGR valve resistance between terminals. (Scheme 34)for terminal identification. See «EGR VALVE RESISTANCE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing) table for specifications.

Scheme 34

EGR VALVE RESISTANCE

EVAP Canister

Remove hoses from EVAP canister. Locate port on canister that goes to fuel tank and blow air into it. There should be no restriction of air flow through canister PURGE pipe and AIR pipe. Plug PURGE and AIR pipes and try to blow into TANK port again. If able to blow air into TANK port, canister is leaking and must be replaced.

EVAP Canister Purge System (Vitara 1.6L & 2.0L)

Raise vehicle in the air so that wheels can rotate freely. Disconnect EVAP canister purge hose and ensure that vacuum does not exist at hose end while engine is idling. Shift transmission to "L" (A/T) or "1st" (M/T), and transfer case to 2H position. Increase engine speed to 1500 rpm or more and ensure that vacuum is now present at purge hose for at least 3 minutes. If operation is not as described, go to EVAP CANISTER PURGE VALVE CIRCUIT and EVAP CANISTER PURGE VALVE for additional tests.

EVAP Canister Purge Valve Circuit

1. Disconnect purge valve vacuum hoses from vacuum pipes. Blow air into purge valve port "A". (Scheme 35) Air should not come out of port "B". If using scan tool, go to next step. If scan tool is not available, go to step 3.
2. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Select MISC TEST mode and use scan tool to turn EVAP canister purge valve on. Blow air into purge valve port "A". Air should now come out of port "B". If purge valve operates as described, purge valve and circuit are working properly. If operation is not as described, inspect for poor connections or open/short circuits in wiring between purge valve, PCM and fuse box. If wiring and connections are okay, go to «EVAP CANISTER PURGE VALVE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing).
3. Turn ignition on. Using fused jumper wire, ground PCM terminal A-7 on Esteem and Swift, C51-2-17 on Vitara 1.6L and 2.0L, and B-1 on Grand Vitara 2.5L. See «PIN VOLTAGE/CIRCUIT RESISTANCE CHARTS»(/suzuki/grand-vitara/i-1997-2001/remont/pin-voltage-charts/#engine-controls-pin-voltagecircuit-resistance-charts) article for PCM connector and terminal identification. Blow air into purge valve port "A". Air should now come out of port "B". If purge valve operates as described, purge valve and circuit are working properly. If operation is not as described, inspect for poor connections or open/short circuits in wiring between purge valve, PCM and fuse box. If wiring and connections are okay, go to «EVAP CANISTER PURGE VALVE»(/suzuki/grand-vitara/i-1997-2001/remont/testing-diagnostics/#engine-controls-system-component-testing).

Scheme 35

1. Turn ignition off. Disconnect EVAP canister purge valve harness connector. Using an ohmmeter, measure resistance between terminals of purge valve. Resistance should be 30-34 at 68°F (20°C) on Esteem and Swift, or 28-36 at 68°F (20°C) on Grand Vitara and Vitara. Resistance between each terminal and body of solenoid should be one megohm or greater. If resistance is as specified, go to next step. If resistance is not as specified, replace EVAP canister purge valve. Retest system.
2. Disconnect vacuum hoses from solenoid. Blow into port "A". (Scheme 35) Air should not flow through solenoid. Using fused jumper wires, connect 12 volts and ground to solenoid terminals. Air should flow through port "B". If operation is not as specified, replace EVAP canister purge valve.

EVAP Canister Air Valve Circuit

Scheme 36

1. Disconnect air valve hose from vapor canister. Blow air into hose "A". (Scheme 36)or (Scheme 37). Air should come out of hose "B". Replace air valve if operation is not as specified. If operation is as specified and a scan tool is available, go to next step. If scan tool is not available, go to step 3.
2. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Select MISC TEST and turn on EVAP canister air valve using scan tool. Blow air into hose "A". Air should no longer come out of hose "B". If operation of air valve is as described, EVAP canister air valve and circuit are okay. If operation is not as described, go to step 4.
3. Using a fused jumper wire, ground PCM connector terminal A-3 on Esteem and Swift, C51-2-5 on Vitara 1.6L and 2.0L, or B-19 on Grand Vitara. See «PIN VOLTAGE/CIRCUIT RESISTANCE CHARTS»(/suzuki/grand-vitara/i-1997-2001/remont/pin-voltage-charts/#engine-controls-pin-voltagecircuit-resistance-charts) article for PCM connector and terminal identification. Blow air into hose "A". Air should no longer come out of hose "B". If operation of air valve is as described, EVAP canister air valve and circuit are okay. If operation is not as described, go to next step.
4. Turn ignition off. Disconnect EVAP canister air valve harness connector. Canister air valve is located on top of EVAP canister. Using an ohmmeter, measure resistance between valve terminals. Resistance should be 25-30 at 68°F (20°C). Resistance between each terminal and body of solenoid should be one megohm or greater. If resistance is as specified, go to next step. If resistance is not as specified, replace EVAP canister air valve. Retest system.
5. Disconnect hoses from solenoid. Blow into port "A". (Scheme 36)or (Scheme 37). Air should flow through valve. Use fused jumper wire to connect battery voltage and ground to air valve terminals. Air should not flow through port "B". If operation is not as specified, replace EVAP canister air valve. If operation is as specified, inspect for poor connections or open/short circuits in wiring between EVAP canister air valve, PCM and fuse box.

EVAP System Leakage Check

1. Disconnect purge hose from intake manifold and tank pressure control valve hose from solenoid vacuum valve. Plug EVAP canister air valve hose end. Connect scan tool to Data Link Connector (DLC). Select MISC TEST mode. Turn canister purge valve on using scan tool. If scan tool is not available, Using fused jumper wire, ground PCM terminal A-7 on Esteem and Swift, C51-2-17 on Vitara 1.6L and 2.0L, and B-1 on Grand Vitara 2.5L. See «PIN VOLTAGE/CIRCUIT RESISTANCE CHARTS»(/suzuki/grand-vitara/i-1997-2001/remont/pin-voltage-charts/#engine-controls-pin-voltagecircuit-resistance-charts) article for PCM connector and terminal identification. Go to next step.
2. Connect vacuum pump to disconnected tank pressure control valve hose. Apply 3.5 kPa (14.0 in Aq) to purge hose and seal it. After 15 seconds, vacuum should still be 3.3 kPa (13.6 in Aq) or more. If system does not meet specified results, leak is present in EVAP system. Locate leak using soapy water or leak detector.

Fuel Tank Pressure Control Valve

1. Disconnect hoses and remove tank pressure control valve. Blow into TANK port. (Scheme 38) Air should flow out of CAN port smoothly when blown hard. If valve operates as specified, go to next step. If valve does not operate as specified, replace tank pressure control valve and retest.
2. Blow air into CAN port. Air should come out of TANK port, even if blown softly. If valve operates as specified, go to next step. If valve does not operate as specified, replace tank pressure control valve and retest.
3. Use vacuum pump attached at vacuum port to open valve. Blow into TANK port. Air should freely flow out of CAN port. If valve does not operate as specified, replace tank pressure control valve and retest.

Scheme 37

Fuel Tank Pressure Sensor

1. Remove tank pressure sensor. Inspect fuel tank pressure sensor for clogged vent hole and pressure passage. Connect three 1.5 volt batteries in series. Connect positive terminal to "Vin" terminal of tank pressure sensor. (Scheme 23) Connect negative terminal to "Ground" terminal. Using a voltmeter, measure voltage between terminals "Vout" and "Ground". Voltage should be approximately 2.5 volts.
2. Connect a hand-held vacuum pump to sensor pressure passage. As vacuum is applied, voltage reading should decrease. Remove vacuum pump and apply light pressure to pressure passage. Voltage should increase. If readings are not as specified, replace tank pressure sensor.

Scheme 38

1. Disconnect vacuum hose from tank pressure control solenoid valve (TPCSV). Start engine and run at idle. Check for vacuum at hose from intake manifold. If vacuum is not present, repair or replace clogged vacuum hose or vacuum passage. If vacuum is present, turn engine off and go to next step.
2. Blow into port "A". see scheme 20 Air should come out of filter and not port "B". Connect scan tool to Data Link Connector (DLC). Turn ignition on. Select MISC TEST mode and use scan tool to turn TCPSV on. If scan tool is not available, remove PCM cover and using fused jumper wire, ground PCM harness connector terminal A-16 on Esteem and Swift, C51-2-6 on Vitara and B-18 on Grand Vitara. Blow into port "A" again. Air should now come out of port "B" and not filter. If operation is as specified, TPCSV, wiring and connections are okay. If operation is not as specified, go to TANK PRESSURE CONTROL SOLENOID VALVE (TPCSV).

Tank Pressure Control Solenoid Valve (TPCSV)

1. Turn ignition off. Disconnect TPCSV harness connector. Using an ohmmeter, measure resistance between terminals of TPCSV. Resistance should be 33-39 ohms on Esteem and Swift, or 28-36 ohms on Grand Vitara and Vitara at 68°F (20°C). Resistance between each terminal and body of solenoid should be one megohm or greater. If resistance is as specified, go to next step. If resistance is not as specified, replace TPCSV. Retest system.
2. Blow into port "A". Air should flow out of filter. see scheme 20 Use fused jumper wires to connect battery voltage and ground to solenoid valve terminals. Blow into port "A". Air should flow out of port "B" and not to filter. If TPCSV operates as specified, check for an open or short circuit between TPCSV, PCM and main relay. See «WIRING DIAGRAMS»(/suzuki/grand-vitara/i-1997-2001/remont/wiring-diagrams-engine-performance/#engine-performance-wiring-diagrams) article. If TPCSV does not operate as specified, replace TPSCV.

POSITIVE CRANKCASE VENTILATION (PCV)

Disconnect PCV valve from valve cover (intake manifold on Swift). Start engine and let idle. Check for vacuum at PCV valve. If vacuum is not present, disconnect PCV valve from hose. If engine runs rough or stalls, replace PCV valve. If engine does not run rough or stall, check for restriction in PCV hose. Repair as necessary. Shake valve and listen for rattle. Replace PCV valve if no rattle is heard.

See also:
• BASIC DIAGNOSTIC PROCEDURES
• PIN VOLTAGE/CIRCUIT RESISTANCE CHARTS
• DTC P0101: MASS AIRFLOW (MAF) PERFORMANCE PROBLEM
• THROTTLE POSITION (TP) SENSOR - GRAND VITARA 2.5L V6
• CIRCUIT TESTS
• IGNITION TIMING
• WIRING DIAGRAMS
• PCM POWER & GROUND CIRCUITS
• EVAP CANISTER PURGE VALVE CIRCUIT