Part 3

1UR-FE ENGINE CONTROL: SFI SYSTEM: P1604: Startability Malfunction
P1604 - Startability Malfunction - Continued

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

(a) Disconnect the ECT sensor connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

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 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

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

62. INSPECT MASS AIR FLOW METER

(a) Connect the Techstream to the DLC3.

(b) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

HINT
The A/C switch and all accessory switches should be off, and the shift lever should be in N or P.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.

(e) Check MAF in the Data List during idling.

Standard:

3.4 to 6.2 gm/sec.

HINT
If the mass air flow meter 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 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

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

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

(a) Disconnect the MAF meter connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

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

65. PERFORM SIMULATION TEST

(a) Remove the EFI NO. 1 and ETCS fuses from the engine room relay block.

(b) After 60 seconds or more elapse, install the EFI NO. 1 and ETCS fuses.

(c) Check if the engine can be started.

Result

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

66. INSPECT AIR FUEL RATIO SENSOR

(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 / Data List / Fuel System Status #1 and Fuel System Status #2.

(e) Confirm that Fuel System Status #1 and Fuel System Status #2 are both CL.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List / AF Lambda B1S1 and AF Lambda B2S1.

(g) Confirm that AF Lambda B1S1 and AF Lambda B2S1 are both 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.

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

Standard Voltage:

Text in Illustration

Result

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 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 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

B -- REPLACE AIR FUEL RATIO SENSOR Removal
A -- Continue to next step.

67. PERFORM SIMULATION TEST

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

OK:

Speed is stable.

HINT
After replacing the fuel injector or mass air flow meter, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal

OK -- REPLACE MASS AIR FLOW METER Removal

68. CHECK FUEL PRESSURE

(a) Inspect the fuel pressure Fuel System.

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

69. 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 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), 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 74 and perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), 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.

70. 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.

*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 74, perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

C -- CHECK MALFUNCTION CONDITION

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

71. CHECK FUEL PRESSURE

HINT
For the fuel pressure inspection, refer to the following procedures Fuel System.

(a) Attach a fuel pressure gauge and check the fuel pressure after stopping the engine.

Result

HINT
* If the engine cannot be started, check the fuel pressure after cranking the engine.
* *1: From step 74, perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

B -- REPLACE PRESSURE REGULATOR Removal

A -- CHECK MALFUNCTION CONDITION

72. 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.
* *1: From step 74, perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), air induction system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

B -- CHECK MALFUNCTION CONDITION

A -- REPLACE FUEL INJECTOR ASSEMBLY Removal

73. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP DUTY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump Duty / 80 %.

(d) 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 74 and perform fuel system troubleshooting A (steps 98 to 105), fuel system troubleshooting B (steps 106 to 108), air induction system troubleshooting (steps 109 to 111), and ignition system troubleshooting (steps 112 to 117), in that order.

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

A -- REPAIR OR REPLACE FUEL LINE

74. 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 75 to 79).

Result

(b) If the malfunction could not be identified during the inspection in step 45, perform ignition system troubleshooting (steps 80 to 85).

Result

(c) If the malfunction could not be identified during the inspection in steps 55, 56, 57, 58 and 59, perform intake air system troubleshooting (steps 86 to 88). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 89 to 96).

Result

(d) If the malfunction could not be identified during the inspection in steps 60, 61, 62, 63, 66, 67, 69, 70, 71, 72 and 73, perform fuel system troubleshooting A (steps 97 to 104), fuel system troubleshooting B (steps 105 to 107), intake air system troubleshooting (steps 108 to 110), and ignition system troubleshooting (steps 111 to 116), in that order.

Result

D -- CHECK FUEL PRESSURE

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

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

75. INSPECT FUEL INJECTOR ASSEMBLY

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

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

76. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR POWER SOURCE)

(a) Disconnect the injector connector.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Text in Illustration

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.

NG -- REPAIR POWER SOURCE CIRCUIT Component Tests and General Diagnostics
OK -- Continue to next step.

77. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM)

(a) Disconnect the injector connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

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.

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

78. CHECK CRANKSHAFT POSITION SENSOR

(a) Replace the crankshaft position sensor Removal.

(b) Check the engine start operation.

OK:

Malfunction has been repaired successfully.

NG -- CHECK CAMSHAFT POSITION SENSOR

OK -- END (CRANKSHAFT POSITION SENSOR IS DEFECTIVE)

79. CHECK CAMSHAFT POSITION SENSOR

(a) Replace the camshaft position sensor Removal.

(b) Check the engine start operation.

OK:

Malfunction has been repaired successfully.

NG -- REPLACE ECM Removal

OK -- END (CAMSHAFT POSITION SENSOR IS DEFECTIVE)

80. CHECK CRANKSHAFT POSITION SENSOR

(a) Check the tightening and installation condition of the crankshaft position sensor bolt.

(b) Check the connection of the crankshaft position sensor connector.

OK:

Sensor is installed correctly.

NG -- SECURELY REINSTALL SENSOR Installation
OK -- Continue to next step.