Part 3
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1604: Startability Malfunction
P1604 - Startability Malfunction
43. CHECK HARNESS AND CONNECTOR (IGNITION COIL POWER SOURCE)
(a) Check the harnesses and connectors, referring to DTC P0351 inspection procedure P0351.
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 -- CHECK IGNITION COIL POWER SOURCE CIRCUIT P0351
OK -- Continue to next step.
44. CHECK HARNESS AND CONNECTOR (IGNITION COIL - ECM)
(a) Check the harnesses and connectors, referring to DTC P0351 inspection procedure P0351.
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 ignition coil assembly, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 69 and perform troubleshooting for the ignition system (steps 74 to 79).
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE IGNITION COIL Removal
45. 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) Using the Techstream, select the [Control the Fuel Pump / Speed] Active Test.
(d) When performing the Active Test, check for an operating sound from the fuel pump.
OK:
HINT
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
NG -- CHECK FUEL PUMP CONTROL CIRCUIT Fuel Pump Control Circuit
OK -- Continue to next step.
46. 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) Using the Techstream, select the [Control the Fuel Pump / Speed] Active Test.
(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 occurs again, proceed to step 69 and perform fuel system troubleshooting C (steps 70 to 73).
B -- CHECK FUEL PUMP CONTROL CIRCUIT Fuel Pump Control Circuit
A -- REPAIR OR REPLACE FUEL LINE
47. READ VALUE USING TECHSTREAM (ENGINE SPEED)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Using the Techstream, select [Engine Speed] of the Data List.
(d) Start the engine.
(e) While running the engine, read the [Engine Speed] value.
OK:
A value that matches the actual engine speed is constantly output.
HINT
- Check the engine speed using a line graph.
- If the engine cannot be started, check the engine speed while cranking the engine.
- If the engine speed is 0 rpm, the crankshaft position sensor may have an open or short circuit.
NG -- REPLACE CRANKSHAFT POSITION SENSOR Removal
OK -- Continue to next step.
48. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR CIRCUIT)
(a) Check the harnesses and connectors, referring to DTC P0300 inspection procedure P0300.
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 -- CHECK FUEL INJECTOR CIRCUIT Fuel Injector Circuit
OK -- REPLACE ECM Removal
49. INSPECT MASS AIR FLOW METER
(a) Inspect the mass air flow meter P0171.
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
OK -- Continue to next step.
50. CHECK INTAKE SYSTEM
(a) Check for air leakage 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 (differ by more than 15%) when idling (intake air volume is small) and almost the same as the normal values when racing the engine (for example, when maintaining a speed of 3000 rpm) (intake air volume is high), air leakage may be present.
OK:
There is no air leakage.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
51. INSPECT 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 DTCs Reading and Clearing Diagnostic Trouble Codes.
B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)
A -- Continue to next step.
52. INSPECT THROTTLE BODY
(a) Check if carbon is in the air flow passage.
OK:
No carbon present.
NG -- REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY
OK -- Continue to next step.
53. 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) Warm up the engine.
(e) Using the Techstream, select the [Control the VVT Linear (Bank1)] Active Test.
HINT
When performing the Active Test, make sure the A/C is on and the shift lever is in P or N (neutral).
(f) Check the engine speed while operating the Oil Control Valve (OCV) using the Techstream.
OK:
Result
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 assembly is stuck ON, the valve overlap increases and combustion worsens due to the internal EGR which may cause the engine to stall.
- *1: From step 69, perform intake system troubleshooting (steps 80 to 82). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 83 to 90).
B -- CHECK MALFUNCTION CONDITION
A -- REPLACE CAMSHAFT TIMING OIL CONTROL VALVE Removal
54. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Check the harnesses and connectors, referring to DTC P0102 inspection procedure P0102.
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, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 69 and perform intake system troubleshooting (steps 80 to 82). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 83 to 90).
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MASS AIR FLOW METER Removal
55. 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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.
56. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
(a) Check the harnesses and connectors, referring to DTC P0115 inspection procedure P0115.
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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
57. INSPECT MASS AIR FLOW METER
(a) Inspect the mass air flow meter P0171.
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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
NG -- REPLACE MASS AIR FLOW METER Removal
OK -- Continue to next step.
58. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Check the harnesses and connectors, referring to DTC P0102 inspection procedure P0102.
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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
59. READ VALUE USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Using the Techstream, select and read [Long FT #1] and [Atmosphere Pressure] in the Data List.
Result
B -- CHECK FUEL PRESSURE
A -- Continue to next step.
60. PERFORM SIMULATION TEST
(a) Remove the EFI and ETCS fuses from the engine room relay block.
(b) After 60 seconds or more elapse, install the EFI and ETCS fuses.
(c) Check if the engine can be started.
Result
B -- CHECK FUEL PRESSURE
A -- Continue to next step.
61. 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.
(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.
(i) Read the output voltage from the air fuel ratio sensor when increasing and decreasing the fuel injection volume.
Standard:
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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
B -- REPLACE AIR FUEL RATIO SENSOR Removal
A -- Continue to next step.
62. PERFORM SIMULATION TEST
(a) Check if the idling speed is stable after starting the engine.
OK:
Engine 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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
NG -- REPLACE FUEL INJECTOR Removal
OK -- REPLACE MASS AIR FLOW METER Removal
63. 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.
64. 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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), 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 69 and perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), 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.
65. 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 69, perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
B -- INSPECT FUEL INJECTOR
C -- CHECK MALFUNCTION CONDITION
A -- Continue to next step.
66. 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 69, perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
A -- CHECK MALFUNCTION CONDITION
B -- REPLACE FUEL PRESSURE REGULATOR Removal
67. INSPECT FUEL INJECTOR
(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 69, perform fuel system troubleshooting A (steps 91 to 98), fuel system troubleshooting B (steps 99 to 101), intake system troubleshooting (steps 102 to 104), and ignition system troubleshooting (steps 105 to 110), in that order.
B -- CHECK MALFUNCTION CONDITION
A -- REPLACE FUEL INJECTOR Removal