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Engine Controls - System/component Tests: Diagnosis Suzuki Sidekick I

Testing & Diagnostics 5 illustrations ~3001 words

Fuel Pump Circuit Test (Samurai)

  1. When ignition switch is first turned on with engine off, fuel pump should operate for 3 seconds. If fuel pump does not operate, connect Pink/Black and Black/White wires of fuel pump relay harness using jumper wire. See «FUEL PUMP RELAY LOCATION»(ref-25813-S28030433202001010500000) table under RELAYS & SOLENOIDS. Turn ignition on. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 4).
  2. If fuel pump operates, check for power at Black/White wire terminal of fuel pump relay. If power is not present, check fuse No. 7 and Black/White wire circuit to fuel pump relay and repair as required. If power is present at Black/White wire terminal of fuel pump relay, check Pink wire ground circuit from fuel pump relay to ECM.
  3. To test fuel pump relay and/or ground circuit, ground Pink wire terminal of fuel pump relay and listen for fuel pump operation. If fuel pump operates, relay is okay. Check Pink wire ground circuit to ECM and repair as required. If ground circuit is okay, replace ECM. If fuel pump does not operate and there is power at Blue/Black and Black/White wire terminals, replace relay.
  4. If fuel pump did not operate in step 1), check for power at Blue/Black wire terminal of relay. If relay terminal has power, check for power at Pink/Blue wire terminal of fuel pump connector. If wire terminal does not have power, repair Pink/Blue wire circuit to fuel pump. If fuel pump does have power, check ground wire circuit. If ground wire circuit is okay, replace fuel pump.

Fuel Pump Circuit Test (Sidekick)

  1. When ignition switch is first turned on with engine off, fuel pump should operate for 3 seconds. If fuel pump operates, fuel pump and main relay circuits are functioning properly. If fuel pump does not operate, disconnect fuel pump relay connector. Using jumper wire, connect Pink/Black and Blue/Black wires of fuel pump relay harness. See «FUEL PUMP RELAY LOCATION»(ref-25813-S28030433202001010500000) table under RELAYS & SOLENOIDS. Turn ignition on. If fuel pump operates, go to next step. If fuel pump does not operate, go to step 5).
  2. If fuel pump operates with jumper wire installed, check for power at Black/Red and Black/White wire terminals of EFI main relay with ignition switch in ON position. If power is not present, check for blown 15-amp fuse(s) in fuse box (fuses No. 8 and 14). If fuses are okay, check wiring between ignition switch and main relay.
  3. If power is present at Black/Red and Black/White wire terminals, turn ignition off. Connect test light to battery voltage. Probe Pink wire of fuel pump relay with test light. Turn ignition switch to ON position. Test light should illuminate for 3 seconds after ignition is turned on. If test light does not illuminate, go to step 4). If test light illuminates for 3 seconds, test fuel pump relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS.
  4. If test light does not illuminate for 3 seconds, check for open in Pink wire between ECM and fuel pump relay harness connector. If wire is okay, check for poor connection of Pink wire at ECM or faulty ECM. See WIRING DIAGRAMS article.
  5. If fuel pump did not operate in step 1), disconnect main relay connector. Using a jumper wire, connect Black/Red and Blue/Black wires of main relay harness connector. If power is now available at Blue/Black wire of fuel pump relay harness, test main relay. If power is not available at Blue/Black wire of fuel pump relay harness, check for blown 15-amp fuse (No. 14) in fuse box. If fuse is okay, repair open in Black/Red wire between fuse box and main relay.

Fuel Pump Circuit Test (Swift DOHC)

  1. Turn ignition on. Operating sound of fuel pump should be heard for 3 seconds. If fuel pump operating sound is heard, fuel pump circuit is okay. If fuel pump operating sound is not heard, go to next step.
  2. Remove fuel pump relay with connector from main fuse box, located near battery. see scheme 7 With fuel pump relay connected, ensure voltage exists at White/Blue wire. If voltage does not exist, check EFI main relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS. With ignition on and engine off, install a jumper wire between fuel pump relay Pink and White/Blue wires. Fuel pump should activate.
  3. If fuel pump activates, go to next step. If fuel pump does not activate, check fuel pump relay connector for poor connection and fuel pump relay Pink wire for an open. If okay, check for faulty fuel pump. See BASIC TESTING article.
  4. If fuel pump activates when fuel pump relay is jumpered, check ignition fuse. If ignition fuse is okay, check for faulty fuel pump relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS. If fuel pump relay is okay, check for open or poor connection between ECM and fuel pump relay Pink/White wire. If wire is okay, substitute a known good ECM and retest.

Fuel Pump Circuit Test (Swift SOHC)

  1. With ignition on and engine off, listen for operating sound of fuel pump. Pump should run for 2 seconds after switch is turned on.
  2. If operating sound is not heard, go to next step. If operating sound is heard, fuel pump circuit is okay. Check fuel pressure to ensure pump is operating at full volume. See BASIC TESTING article.
  3. Remove fuel pump relay. See «FUEL PUMP RELAY LOCATION»(ref-25813-S28030433202001010500000) table under RELAYS & SOLENOIDS. see scheme 7 Apply battery voltage to Pink wire terminal (harness side of connector) and ground to body.
  4. If pump operates, go to next step. If pump does not operate, check continuity of Pink wire between fuel pump relay and pump (in tank). If continuity exists, replace pump. If continuity does not exist, repair circuit.
  5. Turn ignition on. Check for battery voltage on Black/White and White/Blue wire terminals of fuel pump relay connector. If battery voltage is present on both terminals, go to next step. If battery voltage is not present on one or both terminals, check appropriate fuses and feed circuits.
  6. Check fuel pump relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS. If fuel pump relay is okay, check continuity of Pink/White wire between fuel pump relay and ECM connector terminal B10. If circuit is okay, replace ECM.

Fuel Injector Circuit Test (Samurai & Sidekick TBI)

  1. Ensure fuel pressure is within specification. See BASIC TESTING article. If fuel pressure is not within specification, see appropriate FUEL PUMP CIRCUIT TEST under «FUEL DELIVERY»(ref-25813-S38424387552001010500000) .
  2. Check fuel injector operation. See FUEL INJECTOR(S). Turn ignition off. Disconnect injector connector and measure resistance between injector connector terminals. Resistance should be 0.8-1.8 ohms at 68°F (20°C). If resistance is not as specified, replace injector. If resistance is within specification, go to next step.
  3. Disconnect ECM connector "B" from ECM. Measure resistance between connector terminals B8 (Red wire) and B17 (Yellow wire). Resistance should be 0.8-1.8 ohms at 68°F (20°C). If resistance is not as specified, check Red and Yellow wires for short, open or poor connections.

Fuel Injector Circuit Test (Sidekick MPI)

  1. Crank engine and check operating sound of each fuel injector. If operating sound can be heard from all 4 fuel injectors, fuel injector circuit is okay. If no operating sound at all is heard from any fuel injector, go to next step. If one or more fuel injector(s) makes no operating sound, go to step 4).
  2. If no operating sound is heard from any fuel injector, turn ignition off. Disconnect harness connector from injector No. 1. Turn ignition on. Measure voltage between ground and fuel injector No. 1 harness connector terminal Blue/Black wire. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check EFI main relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS. Repair or replace relay as necessary.
  3. Turn ignition off. Disconnect injector connector and measure resistance between injector connector terminals. Resistance should be 12-17 ohms at 68°F (20°C). If resistance is not as specified, replace injector. If resistance is within specification, substitute a known good ECM and retest.
  4. Disconnect harness connector of injector not making operating sound. Measure resistance between injector connector terminals. Resistance should be 12-17 ohms at 68°F (20°C). If resistance is not as specified, replace injector. If resistance is within specification, substitute a known good ECM and retest.

Fuel Injector Circuit Test (Swift DOHC)

  1. Crank engine and check operating sound of each fuel injector. If operating sound can be heard from all 4 fuel injectors, fuel injector circuit is okay. If no operating sound at all is heard from any fuel injector, go to next step. If one or more fuel injector(s) makes no operating sound, go to step 6).
  2. If no operating sound is heard at all from any fuel injector, turn ignition off. Disconnect ECM 10-pin connector.
  3. Using an ohmmeter, check for continuity between ECM 10-pin connector terminals C3 and C8. see scheme 9 If continuity does not exist, check for open between terminals C3 and C8 or poor connections at fuel injector. Check for continuity between terminal C5 and ground. If continuity does not exist, check C5 wire for open or poor ground.
  4. Disconnect ohmmeter. Turn ignition on. Using a voltmeter, check for battery voltage between ECM terminal C2 and ground. If battery voltage is not present, check for open circuit. Check EFI main relay. See «RELAYS»(ref-25813-S34652804772001010500000) under RELAYS & SOLENOIDS. If ohmmeter and volt-meter readings are okay, go to next step.
  5. If ohmmeter and voltmeter readings are okay, check connections at ECM 10-pin connector terminal C3 to C4, C8 to C9, C5 to C10, and C2 to C7. (Scheme 97) If connections are okay, substitute a known good ECM and retest.
  6. If one or more fuel injector(s) makes no operating sound, check each fuel injector connector for poor connection. If okay, check fuel injectors. See FUEL INJECTOR(S).

Scheme 97

Scheme 97
Scheme 97

Fuel Injector Circuit Test (Swift SOHC)

  1. Turn ignition on. If fuel is not injected from injector when ignition is turned on (without cranking engine), go to step 3). If fuel is injected from injector when ignition is turned on (without cranking engine), go to next step.
  2. Check for short to ground in Yellow/Black wire between injector and ECM. If wire is okay, check fuel injector and fuel injector resistor. See FUEL INJECTOR(S) and FUEL INJECTOR RESISTOR (SWIFT SOHC). If fuel injector and fuel injector resistor are okay, replace ECM.
  3. Crank engine. If fuel is NOT injected during cranking, go to step 4). If fuel is injected during cranking, turn ignition off and check fuel injector for leaks. See FUEL INJECTOR(S). If fuel injector leaks, replace fuel injector. If fuel injector does not leak, fuel injector circuit is okay.
  4. Listen for operating sound of fuel injector while cranking engine. If operating sound is not heard, go to next step. If operating sound is heard, check fuel pump. See appropriate FUEL PUMP CIRCUIT TEST under «FUEL DELIVERY»(ref-25813-S38424387552001010500000) .
  5. Turn ignition off. Disconnect fuel injector connector. Check resistance between fuel injector connector terminals. If resistance is 0.5-1.5 ohms at 68°F (20°C), go to step 7). If resistance is not within specification, check for open sub-wires (short section of wires between fuel injector and connector).
  6. If sub-wires are okay, check for poor connection at sub-wire connector. If connection is okay, replace fuel injector.
  7. Check fuel injector resistor. See FUEL INJECTOR RESISTOR (SWIFT SOHC). Replace fuel injector resistor if not within specification. If fuel injector resistor is okay, turn ignition off. Connect fuel injector and fuel injector resistor connectors.
  8. Disconnect 12-pin ECM connector. Turn ignition on. If battery voltage is present on ECM terminal A2, go to next step. If battery voltage is not present, repair open in circuit between EFI main relay and ECM.
  9. Check for poor connection at ECM connector terminal A2. If connection is good, replace ECM.

System Test

  1. Warm engine to normal operating temperature. Turn engine off. Ensure throttle opener slightly opens throttle valve with engine off and while engine is cranking. If throttle valve opens, go to step 3).
  2. If throttle valve does not open, check throttle opener diaphragm. See THROTTLE OPENER DIAPHRAGM. Replace throttle opener if defective. If throttle opener is okay, adjust throttle opener. See ADJUSTMENTS article.
  3. Note if throttle opener rod retracts within one second after engine starts. If rod retracts, check throttle opener adjustment. See ADJUSTMENTS article. Adjust as necessary. If rod does not retract, go to next step.
  4. Check vacuum hoses to throttle opener. If vacuum hoses are okay, check throttle opener diaphragm. See THROTTLE OPENER DIAPHRAGM. Replace components as necessary. If components are okay, go to next step.
  5. Check throttle opener Vacuum Switching Valve (VSV). See THROTTLE OPENER VACUUM SWITCHING VALVE. If VSV is okay, go to next step. Replace VSV if defective.
  6. Turn ignition on. Check for battery voltage between ground and ECM terminal B14 (Light Green/White wire). ECM is located near glove compartment on Samurai or upper left corner of instrument panel on Sidekick.
  7. If battery voltage is present, go to next step. If battery voltage is not present, check for defective connection at VSV, defective wiring between ECM and VSV or defective wiring between VSV and EFI main relay (Samurai) or control relay (Sidekick). If wiring and connections are okay, replace ECM and recheck operation.
  8. While cranking engine, check for voltage on ECM connector terminal B14 (Light Green/White wire). If voltage is not present, ECM is okay. If voltage is present, go to next step.
  9. While cranking engine, check for battery voltage on ECM connector terminal B11 (Black/Yellow wire). If battery voltage is present, go to next step. If battery voltage is not present, check for open or short to ground in Black/Yellow wire between ECM and starter.
  10. Check for defective connection at ECM. If connection is okay, replace ECM and recheck system operation.

EGR System Test (Samurai Calif.)

ECM will set a Code 51 if EGR system failure is present. Signal comes from Exhaust Gas Recirculation Temperature (EGRT) sensor. See appropriate TESTS W/CODES article for system diagnosis.

EGR System Test (Samurai Federal)

  1. Before checking EGR system, ensure throttle position sensor, coolant temperature sensor and pressure sensor are operating correctly. See THROTTLE POSITION (TP) SENSOR, ENGINE COOLANT TEMPERATURE (ECT) SENSOR and MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR under ENGINE SENSORS & SWITCHES.
  2. Ensure 5th gear switch signal is not applied to ECM. Check for 5th gear switch signal at terminal A5 (Light Blue wire) of ECM. ECM is located behind glove compartment. If voltage is present, check 5th gear switch circuit. See WIRING DIAGRAMS article.
  3. To check EGR system, place transmission in Neutral. Apply parking brake. With coolant temperature less than 127°F (53°C), start engine and operate at high RPM. EGR diaphragm should not move.
  4. Warm engine to normal operating temperature. Operate engine at high RPM. EGR valve diaphragm should retract during acceleration.
  5. If EGR valve does not operate as specified, check for misrouted, restricted, clogged or deteriorated vacuum hoses. If vacuum hoses are okay, check EGR valve and EGR modulator. See EGR VALVE and EGR MODULATOR.
  6. If EGR valve and EGR modulator are okay, check EGR Vacuum Switching Valve (VSV). See EGR VACUUM SWITCHING VALVE (VSV).
  7. If VSV is okay, check for open or short in wiring circuit. (Scheme 98) Check for defective connections at ECM and VSV. If connections are okay, check EFI main relay. See RELAYS under RELAYS & SOLENOIDS. If all components and wiring are okay, substitute a known good ECM and recheck.

Scheme 98

Scheme 98
Scheme 98

EGR System Test (Sidekick Calif.)

ECM will set a Code 51 if EGR system failure is present. Signal comes from Exhaust Gas Recirculation Temperature (EGRT) sensor. See appropriate TESTS W/CODES article for system diagnosis.

EGR System Test (Sidekick Federal)

  1. Place transmission in Park (A/T) or Neutral (M/T) and transfer case lever in 2H position. Apply parking brake. With coolant temperature less than 131°F (55°C), start engine and operate at high RPM. EGR valve diaphragm should not retract.
  2. Warm engine to normal operating temperature. Operate engine at high RPM. EGR valve diaphragm should retract.
  3. If EGR valve does not operate as specified, check for misrouted, restricted, clogged or deteriorated vacuum hoses. If vacuum hoses are okay, check EGR valve, EGR modulator, VSV, wire harness and ECM. See EGR VALVE and EGR MODULATOR. (Scheme 98)or (Scheme 99).
  4. If EGR valve and EGR modulator are okay, check EGR Vacuum Switching Valve (VSV). See EGR VACUUM SWITCHING VALVE (VSV).
  5. If VSV is okay, disconnect ECM connector. On MPI, check Light Green/White wire from terminal A15. On TBI, check Light Green/Yellow wire from terminal A5 for short to ground, an open circuit, or poor connections at ECM or VSV connectors. On all models, if wires and connections are okay, replace ECM with a known good unit and retest.

Scheme 99

Scheme 99
Scheme 99

EGR System Test (Swift Calif.)

ECM will set a Code 51 if EGR system failure is present. This signal comes from the Exhaust Gas Recirculation Temperature (EGRT) sensor. See appropriate TESTS W/CODES article for system diagnosis.

EGR System Test (Swift Federal)

  1. To check system operation, place transaxle in Park (A/T) or Neutral (M/T). Apply parking brake.
  2. With coolant temperature less than 122°F (50°C) on DOHC models, or 104°F (40°C) on SOHC models, start engine and operate at high RPM. EGR valve diaphragm should not retract.
  3. Warm engine to normal operating temperature. Operate engine at high RPM. EGR valve diaphragm should retract.
  4. If EGR valve does not operate as specified, check for misrouted, restricted, clogged or deteriorated vacuum hoses. If vacuum hoses are okay, check EGR valve and EGR modulator. See EGR VALVE and EGR MODULATOR. (Scheme 100)or (Scheme 101).
  5. If EGR valve and EGR modulator are okay, check EGR Vacuum Switching Valve (VSV). See EGR VACUUM SWITCHING VALVE (VSV).
  6. If VSV is okay, check wiring and ECM. ECM will set a Code 51 if EGR system failure is present. See appropriate TESTS W/CODES article for system diagnosis.
  7. To check for clogged EGR passages, allow engine to idle. Manually open EGR valve. Engine RPM should decrease. If engine speed does not decrease, check for clogged EGR passages.

Scheme 100

Scheme 100
Scheme 100

Scheme 101

Scheme 101
Scheme 101

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