Part 6

2ZR-FE ENGINE CONTROL: SFI SYSTEM: P1604; Startability Malfunction; 2013 MY Corolla [07/2012 -]
P1604 - Startability Malfunction

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 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 / 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 Heated Oxygen Sensor.

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.

B -- REPLACE SPARK PLUG (ABNORMAL CYLINDER) Removal

C -- REPLACE SPARK PLUG (ALL 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.

B -- CHECK FUEL INJECTOR ASSEMBLY

C -- CHECK MALFUNCTION CONDITION
A -- Continue to next step.