Engine Control System: Diagnosis Scion xB I

ON-VEHICLE INSPECTION

1. INSPECT THROTTLE BODY IDLE SPEED CONTROL VALVE ASSY NOTE: Since the Idle Speed Control Valve (ISC valve) has an internal IC circuit which converts the ECM duty signal into the drive signal, it is impossible to check its resister value and valve operation with the valve alone. Clear the DTC after inspection. HINT: DTC P0505 will be set when the ISC valve is stuck. Check the operation. Connect the ISC valve connector to the ISC valve. Check the valve movement when the ignition switch is turned ON. Movement: Half open -> fully close -> fully open -> half open HINT: The series of the valve movement mentioned above is done within 0.5 second.

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

1. INSPECT MASS AIR FLOW METER Output voltage inspection. Apply battery voltage across terminals 1 (+B) and 2 (E2G). Connect the positive (+) tester probe to terminal VG, and negative (-) tester probe to terminal E2G. Blow air into the mass air flow meter, and check that the voltage output fluctuates. Inspect the resistance. Using an ohmmeter, measure the resistance between terminals 4 (THA) and 5 (E2). Resistance: MASS AIR FLOW METER SPECIFICATIONS Terminals Resistance Temperature THA - E2 13.6 to 18.4 kohm -20°C (-4°F) 2.21 to 2.69 kohm 20°C (68°F) 0.49 to 0.67 kohm 60°C (140°F)
2. INSPECT CAMSHAFT TIMING OIL CONTROL VALVE ASSY Inspect the resistance. Using an ohmmeter, measure the resistance between the terminals. Resistance: 6.9 to 7.9 ohm at 20°C (68°F) Check the operation. Connect the battery positive (+) lead to terminal 1 and negative (-) lead to terminal 2, and check the movement of the valve. NOTE: Confirm that the valve moves freely and is not stuck in any position. HINT: Foreign objects in the oil can cause subtle pressure leaks in the valve. The pressure leaks will cause the cam to advance. This condition will usually set a DTC.
3. INSPECT THROTTLE BODY ASSY Check the throttle body. Check that the throttle valve shaft is not rickety. Check that all ports are not clogged. Check that the throttle valve opens and closes smoothly. Check that there is no clearance between the throttle stop screw and throttle lever at the throttle valve closed position. NOTE: Do not touch the throttle stop screw.
4. INSPECT THROTTLE POSITION SENSOR Inspect the resistance. Disconnect the throttle position sensor connector. Using an ohmmeter, measure the resistance between terminals VC and E2. Resistance: 2.5 to 6.0 kohm Check the variation in resistance between terminals VTA and E2. Variation in resistance: The resistance value increases in proportion to the throttle lever opening value. HINT: THROTTLE POSITION SENSOR SPECIFICATIONS Throttle Valve Movement Resistance Fully open 1.9 to 4.9 kohm Fully close 0.2 to 1.0 kohm
5. INSPECT ENGINE COOLANT TEMPERATURE SENSOR Inspect the resistance. Using an ohmmeter, measure the resistance between each terminal. Resistance: 2.29 to 2.60 kohm at 20°C (68°F) 0.301 to 0.327 kohm at 80°C (176°F) NOTE: If checking the engine coolant temperature sensor in water, be careful not to allow water to intrude the terminals. After checking, dry the sensor.
6. INSPECT KNOCK SENSOR Inspect the resistance. Using an ohmmeter, measure the resistance between the terminal and body. Standard resistance: 10 kohm or higher If the result is not as specified, replace the knock sensor.
7. INSPECT EFI RELAY Inspection the resistance Using an ohmmeter, measure the resistance between each terminal. Specified condition: EFI RELAY SPECIFICATIONS Tester Connection Specified Condition 3 - 5 10 kohm or higher 3 - 5 Below 1ohm (Apply battery voltage to terminals 1 and 2) If the result is not as specified, replace the EFI relay.
8. INSPECT CIRCUIT OPENING RELAY Inspect the resistance. Using an ohmmeter, measure the resistance between each terminal. Specified condition: CIRCUIT OPENING RELAY SPECIFICATIONS Tester Connection Specified Condition 3 - 5 10 kohm or higher 3 - 5 Below 1ohm (Apply battery voltage to terminals 1 and 2) If the result is not as specified, replace the EFI relay.

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

1. DRAIN ENGINE COOLANT (See «ENGINE COOLANT (1NZ-FE) (FROM APRIL, 2004)»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling) )
2. REMOVE AIR CLEANER ASSY Disconnect the mass air flow meter connector. Disconnect the VSV connector. Remove the wire harness clamp. Disconnect the fuel vapor feed hose No. 2. Disconnect the ventilation hose. Disconnect the fuel vapor feed hose No. 1. Unlock the 2 clamp hooks. Loosen the hose clamp and remove the air cleaner cap. Remove the air cleaner filter element. Remove the 4 bolts and air cleaner case.
3. SEPARATE ACCELERATOR CONTROL CABLE ASSY Loosen the nut and separate the accelerator control cable.
4. REMOVE TRANSMISSION OIL LEVEL GAGE SUB-ASSY (AUTOMATIC TRANSAXLE)
5. REMOVE TRANSMISSION OIL FILLER TUBE SUB-ASSY (AUTOMATIC TRANSAXLE) Disconnect the throttle position sensor connector. Disconnect the hose. Remove the bolt and oil cooler tube clamp. Remove the bolt and transmission oil filler tube. Remove the O-ring from the transmission oil filler tube.
6. REMOVE THROTTLE BODY ASSY Disconnect the ISC valve connector. Disconnect the throttle position sensor connector. (MANUAL TRANSAXLE) Remove the wire harness clamp. Remove the bolt and 2 nuts, then remove the accelerator control cable bracket and throttle body. Remove the gasket from the intake manifold. Disconnect the water by-pass hose. Disconnect the water by-pass hose No. 2.
7. REMOVE ISC VALVE Remove the 3 screws and ISC valve. Remove the gasket from the throttle body.
8. REMOVE THROTTLE POSITION SENSOR Remove the 2 screws and throttle position sensor.
9. INSTALL THROTTLE POSITION SENSOR Confirm that the throttle valve is fully closed. Insert the throttle position sensor into the throttle body, then turn the throttle position sensor 45° clockwise until the throttle valve is in the fully closed throttle position. Torque: 2.0 N.m (20 kgf.cm, 17 in.lbf)
10. INSTALL ISC VALVE Install a new gasket onto the throttle body. Install the ISC valve with the 3 screws. Torque: 3.4 N.m (35 kgf.cm, 30 in.lbf)
11. INSTALL THROTTLE BODY ASSY Connect the water by-pass hose No. 2. Connect the water by-pass hose. Install a new gasket onto the intake manifold. Install the throttle body and accelerator control bracket with the bolt and 2 nuts. Torque: 30 N.m (306 kgf.cm, 22 ft.lbf) Install the wire harness clamp. Connect the throttle position sensor connector. (MANUAL TRANSAXLE) Connect the ISC valve connector.
12. INSTALL TRANSMISSION OIL FILLER TUBE SUB-ASSY (AUTOMATIC TRANSAXLE) Install a new O-ring onto the transmission oil filler tube. Install the transmission oil filler tube with the bolt. Torque: 5.5 N.m (56 kgf.cm, 49 in.lbf) Install the oil cooler tube clamp with the bolt. Torque: 5.5 N.m (56 kgf.cm, 49 in.lbf) Connect the hose. Connect the throttle position sensor connector.
13. INSTALL TRANSMISSION OIL LEVEL GAGE SUB-ASSY (AUTOMATIC TRANSAXLE)
14. INSTALL ACCELERATOR CONTROL CABLE ASSY Install the accelerator control cable (Scheme 21) Torque: 13 N.m (133 kgf.cm, 10 ft.lbf)
15. INSTALL AIR CLEANER ASSY Secure the air cleaner case to the air cleaner bracket with the 3 bolts. Torque: 7.8 N.m (80 kgf.cm, 69 in.lbf) Secure the air cleaner inlet to the engine compartment with the bolt. Torque: 7.5 N.m (76 kgf.cm, 66 in.lbf)
16. ADD ENGINE COOLANT (See «ENGINE COOLANT (1NZ-FE) (FROM APRIL, 2004)»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling) )
17. CHECK FOR ENGINE COOLANT LEAKS (See «ON-VEHICLE INSPECTION»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling__on-vehicle-inspection) )

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

1. DRAIN ENGINE COOLANT (See «ENGINE COOLANT (1NZ-FE) (FROM APRIL, 2004)»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling) )
2. REMOVE AIR CLEANER ASSY (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
3. SEPARATE ACCELERATOR CONTROL CABLE ASSY (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
4. REMOVE TRANSMISSION OIL LEVEL GAGE SUB-ASSY (AUTOMATIC TRANSAXLE)
5. REMOVE TRANSMISSION OIL FILLER TUBE SUB-ASSY (AUTOMATIC TRANSAXLE) (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
6. SEPARATE THROTTLE BODY ASSY Disconnect the ISC valve connector. Disconnect the throttle position sensor connector. (MANUAL TRANSAXLE) Remove the wire harness clamp. Remove the bolt and 2 nuts, then remove the accelerator control cable bracket and throttle body. Remove the gasket from the intake manifold.
7. REMOVE CYLINDER HEAD COVER NO. 2 Remove the 4 nuts and cylinder head cover.
8. DISCONNECT RADIATOR HOSE INLET
9. REMOVE OIL LEVEL GAGE SUB-ASSY
10. REMOVE INTAKE MANIFOLD Disconnect the ventilation hose. Disconnect the union to connector tube hose. Remove the 3 wire harness clamps. In order to remove the intake manifold, using several steps, remove the 3 bolts and 2 nuts in the sequence (Scheme 29) Remove the gasket from the intake manifold.
11. REMOVE KNOCK SENSOR Disconnect the knock sensor connector. Using SST, remove the knock sensor. SST 09816-30010
12. INSTALL KNOCK SENSOR Using SST, install the knock sensor. SST 09816-30010 Torque: 44 N.m (450 kgf.cm, 32 ft.lbf) Connect the knock sensor connector.
13. INSTALL INTAKE MANIFOLD Install a new gasket onto the intake manifold. Install the intake manifold with the 3 bolts and 2 nuts. Using several steps, tighten the bolts and nuts uniformly in the sequence see scheme 31 Torque: 30 N.m (306 kgf.cm, 22 ft.lbf) Install the 3 wire harness clamps. Connect the union to connector tube hose. Connect the ventilation hose.
14. INSTALL OIL LEVEL GAGE SUB-ASSY
15. CONNECT RADIATOR HOSE INLET
16. INSTALL CYLINDER HEAD COVER NO. 2 Install the cylinder head cover. First tighten nut A, then tighten nut B. Torque: 7.0 N.m (71 kgf.cm, 62 in.lbf)
17. INSTALL THROTTLE BODY ASSY Install a new gasket onto the intake manifold. Install the throttle body and accelerator control cable bracket with the bolt and 2 nuts. Torque: 30 N.m (306 kgf.cm, 22 ft.lbf) Install the wire harness clamp. Connect the throttle position sensor connector. (MANUAL TRANSAXLE) Connect the ISC valve connector.
18. INSTALL TRANSMISSION OIL FILLER TUBE SUB-ASSY (AUTOMATIC TRANSAXLE) (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
19. INSTALL TRANSMISSION OIL LEVEL GAGE SUB-ASSY (AUTOMATIC TRANSAXLE)
20. INSTALL ACCELERATOR CONTROL CABLE ASSY (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
21. INSTALL AIR CLEANER ASSY (See «REMOVAL & INSTALLATION AND DISASSEMBLY & REASSEMBLY»(ref-224532-S27964845242006031000000) )
22. ADD ENGINE COOLANT (See «ENGINE COOLANT (1NZ-FE) (FROM APRIL, 2004)»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling) )
23. CHECK FOR ENGINE COOLANT LEAKS (See «ON-VEHICLE INSPECTION»(/scion/xb/i-2003-2007/remont/cooling-system-mechanical/#cooling__on-vehicle-inspection) )

See also:
• ENGINE COOLANT (1NZ-FE) (FROM APRIL, 2004)
• ON-VEHICLE INSPECTION