Part 3

2ZR-FE ENGINE CONTROL: SFI SYSTEM: P1604: Startability Malfunction
P1604 - Startability Malfunction - Continued

50. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

(a) Disconnect the fuel injector assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Standard Resistance (Check for Short):

HINT
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* Make sure there is not an excessive amount of force applied to the wire harness.

(d) Reconnect the ECM connector.

(e) Reconnect the fuel injector assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal

51. INSPECT MASS AIR FLOW METER

(a) Inspect the mass air flow meter sub-assembly On-Vehicle Inspection.

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
OK -- Continue to next step.

52. CHECK INTAKE SYSTEM

(a) Check for air suction in the intake system [vacuum hose disconnection, cracks, damaged gaskets, etc.] Intake System.

HINT
* If the accelerator pedal is released after racing the engine, the inspection is easier to perform because the vacuum inside the intake manifold increases and the air suction noise becomes louder.
* If Short FT #1 and Long FT #1 are largely different from the normal values when idling (intake air volume is small) and almost the same as the normal values when racing the engine (intake air volume is high), air leakage may be present.

Standard:

There is no air suction.

NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.

53. CHECK THROTTLE BODY

(a) Disconnect the throttle body connector.

HINT
When the connector is disconnected, the vehicle enters fail-safe mode and the throttle valve opening angle is 4 to 7°.

(b) Crank the engine and check that it starts.

Result:

(c) Connect the throttle body connector.

HINT
When this inspection is performed, the MIL may illuminate. After finishing the inspection, check and clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)
A -- Continue to next step.

54. CHECK THROTTLE BODY

(a) Check if carbon is in the air flow passage.

Standard:

No carbon present.

NG -- REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY
OK -- Continue to next step.

55. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Linear (Bank 1).

HINT
When performing the Active Test, make sure the A/C is on and the shift lever is in neutral.

(e) Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.

OK:

HINT
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* When the results of the inspection using the Active Test are normal but the valve operating noise is abnormal, check the valve for any signs of problems.
* If the camshaft timing oil control valve is stuck on, the valve overlap increases and combustion worsens due to the internal EGR which may cause rough idle or cause the engine to stall.

NG -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY Removal
OK -- Continue to next step.

56. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT EXHAUST LINEAR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Exhaust Linear (Bank 1).

(e) Check the engine speed while operating the oil control valve using the Techstream.

OK*:

Result:

HINT
* *: From step 73, perform intake system troubleshooting (steps 89 to 91). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 92 to 99).
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* When the results of the inspection using the Active Test are normal but the valve operating noise is abnormal, check the valve for any signs of problems.
* If the camshaft timing oil control valve is stuck on, the valve overlap increases and combustion worsens due to the internal EGR which may cause rough idle or cause the engine to stall.

B -- CHECK MALFUNCTION CONDITION

A -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY Removal

57. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Standard Resistance (Check for Short):

HINT
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* Make sure there is not an excessive amount of force applied to the wire harness.
* If the wire harness is normal, after replacing the mass air flow meter sub-assembly, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 73 and perform intake system troubleshooting (steps 89 to 91). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 92 to 99).

(d) Reconnect the ECM connector.

(e) Reconnect the mass air flow meter sub-assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MASS AIR FLOW METER Removal

58. INSPECT ENGINE COOLANT TEMPERATURE SENSOR

(a) Inspect the engine coolant temperature sensor Testing and Inspection.

HINT
If the engine coolant temperature sensor is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.

59. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)

(a) Disconnect the engine coolant temperature sensor connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Standard Resistance (Check for Short):

HINT
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* Make sure there is not an excessive amount of force applied to the wire harness.
* If the wire harness or connector is malfunctioning, after replacing or repairing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

(d) Reconnect the ECM connector.

(e) Reconnect the engine coolant temperature sensor connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

60. INSPECT MASS AIR FLOW METER

(a) Inspect the mass air flow meter sub-assembly On-Vehicle Inspection.

HINT
If the mass air flow meter sub-assembly is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

NG -- REPLACE MASS AIR FLOW METER Removal
OK -- Continue to next step.

61. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Standard Resistance (Check for Short):

B -- CHECK FUEL PRESSURE
A -- Continue to next step.

63. PERFORM SIMULATION TEST

(a) Remove the EFI MAIN and ETCS fuses from the engine room relay block.

(b) After 60 seconds or more elapse, install the EFI MAIN and ETCS fuses.

(c) Check if the engine can be started.

Result:

B -- CHECK FUEL PRESSURE
A -- Continue to next step.

64. INSPECT AIR FUEL RATIO SENSOR

(a) Connect the Techstream to the DLC3.

(b) Start the engine, turn off all accessory switches and warm up the engine until the engine coolant temperature stabilizes.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Fuel System Status #1.

(e) Confirm that Fuel System Status #1 is CL.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List / AF Lambda B1S1.

(g) Confirm that AF Lambda B1S1 is within the range of 0.95 to 1.05 when idling.

(h) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2.

(i) Read the output voltage from the air fuel ratio sensor when increasing and decreasing the fuel injection volume.

Standard:

HINT
* The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
* If there is almost no response from the air fuel ratio sensor, a malfunction of the air fuel ratio sensor is suspected.
* If the air fuel ratio sensor is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.

65. INSPECT HEATED OXYGEN SENSOR

(a) Inspect the heated oxygen sensor Component Tests and General Diagnostics.

HINT
If the heated oxygen sensor is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

NG -- REPLACE HEATED OXYGEN SENSOR Removal
OK -- Continue to next step.

66. PERFORM SIMULATION TEST

(a) Check if the idling speed is stable after starting the engine.

OK:

Idling speed is stable.

HINT
After replacing the fuel injector assembly or mass air flow meter sub-assembly, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal

OK -- REPLACE MASS AIR FLOW METER Removal

67. CHECK FUEL PRESSURE

(a) Inspect the fuel pressure Fuel System.

NG -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED)
OK -- Continue to next step.

68. INSPECT SPARK PLUG

(a) Inspect the spark plugs Testing and Inspection.

Result:

HINT
* *1: If one cylinder is abnormal, replace the spark plug of that cylinder and inspect the ignition and fuel system for that cylinder. After performing repairs, check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.
* *2: If all cylinders are abnormal, replace the spark plugs of all cylinders and check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.
* *3: Engine starting trouble may occur if the vehicle is driven extremely short distances repeatedly.

C -- REPLACE SPARK PLUG (ALL CYLINDER) Removal

B -- REPLACE SPARK PLUG (ABNORMAL CYLINDER) Removal
A -- Continue to next step.

69. CONFIRM VEHICLE CONDITION

(a) Confirm the conditions present when the malfunction occurred based on the customer problem analysis.

Result:

HINT
*1: The pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.

*2: Fuel may be leaking from a fuel injector assembly.

*3: The pressure regulator may not be able to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.

*4: From step 73, perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

C -- CHECK MALFUNCTION CONDITION

B -- CHECK FUEL INJECTOR ASSEMBLY
A -- Continue to next step.

71. CHECK FUEL INJECTOR ASSEMBLY

(a) Clean the inside of the surge tank with compressed air.

(b) After stopping the engine, measure the HC concentration inside the surge tank for 15 minutes.

Result:

HINT
* If the concentration is 400 ppm or higher, a fuel injector may have a sealing problem.
* *: From step 73, perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

B -- CHECK MALFUNCTION CONDITION

A -- REPLACE FUEL INJECTOR ASSEMBLY Removal

72. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump/Speed.

(e) When performing the Active Test, check for fuel leakage from the fuel pipes.

Result:

HINT
* Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
* Check if the vehicle ran out of fuel, as engine starting trouble due to running out of fuel is also detected.
* If there are no fuel leaks, after inspecting the fuel pump control system, check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 73 and perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

B -- CHECK FUEL PUMP CONTROL CIRCUIT Component Tests and General Diagnostics

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR

73. CHECK MALFUNCTION CONDITION

(a) If the malfunction could not be identified during the inspection in steps 38, 39, 40 and 47, perform fuel system troubleshooting C (steps 74 to 79).

Result:

(b) If the malfunction could not be identified during the inspection in step 45, perform ignition system troubleshooting (steps 80 to 88).

Result:

(c) If the malfunction could not be identified during the inspection in steps 55, 56 and 57, perform intake air system troubleshooting (steps 89 to 91). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 92 to 99).

Result:

(d) If the malfunction could not be identified during the inspection in steps 58, 59, 60, 61, 64, 65, 66, 68, 69, 70, 71, 72, perform fuel system troubleshooting A (steps 100 to 107), fuel system troubleshooting B (steps 108 to 110), intake air system troubleshooting (steps 111 to 113), and ignition system troubleshooting (steps 114 to 122), in that order.

Result:

D -- CHECK FUEL PRESSURE

C -- READ VALUE USING TECHSTREAM (ISC LEARNING VALUE)

B -- CHECK SENSOR INSTALLATION (CRANKSHAFT POSITION SENSOR)
A -- Continue to next step.

74. INSPECT FUEL INJECTOR ASSEMBLY

(a) Inspect the fuel injectors assembly Testing and Inspection.

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal
OK -- Continue to next step.