Part One

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

DESCRIPTION

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.

1. Reference waveforms showing a normal cold engine start

2. Reference waveforms showing a normal warm engine start

3. Reference waveforms showing an engine stop after normal idling

4. Reference values when there is an air leak in the intake system during starting difficulty

INSPECTION PROCEDURE

HINT
- In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1604 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as starting difficulty.
As these DTCs can be stored as a result of certain user actions, even if these DTCs are output, if the customer makes no mention of problems, clear these DTCs without performing any troubleshooting and return the vehicle to the customer.
- If any other DTCs are output, perform troubleshooting for those DTCs first.
- When the Data List item "Immobiliser Fuel Cut" is ON, the engine cannot be started.
- Read freeze frame data using the Techstream. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
- When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data Freeze Frame Data.
- When confirming freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
- Try to start the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and compare it with the freeze frame data.
- If the malfunction does not reoccur, carefully check the vehicle conditions from when the malfunction occurred using freeze frame data.
- When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.
- If the same inspection or replacement procedure appears 2 times when performing an inspection procedure, it is not necessary to repeat the procedure the second time.

1. Malfunction Recurrence and Inspection Areas

(a) Freeze frame data exists, but the malfunction (starting difficulty) has not reoccurred and the malfunction conditions are unknown.

(1) The engine speed recorded in the freeze frame data is 0 rpm (the engine does not crank).

HINT
One of the following problems may be present: battery depletion, excess engine friction, a starter malfunction or a crankshaft position sensor malfunction.

* If the battery voltage is less than 6 V during cranking, there is a high probability that engine friction is abnormal.

* If the battery voltage drops to 5 V or less when starting the engine, the battery may be malfunctioning.

* If the battery voltage fluctuates while cranking the engine, it can be concluded that cranking is being performed. When the engine speed is 0 rpm, the crankshaft position sensor and/or an ECM may be malfunctioning.

(2) All engine speeds recorded in the freeze frame data are between 100 and 250 rpm (the engine cranks but there is no combustion).

HINT
If the engine speed is between 100 and 250 rpm (no initial combustion), there may be a wiring problem or a complete failure of an ignition or fuel system part.

* Due to an engine coolant temperature sensor malfunction, the fuel injection volume is extremely high or low and the engine may not be able to be started.

(3) The engine speed recorded in the freeze frame data is 250 rpm or higher (the initial combustion and starter turnoff timing is too late).

HINT
If the engine speed is 250 rpm or higher (combustion occurs but the initial combustion and starter turnoff timing is too late), the fuel injection volume is often incorrect (too low or too high) and determining the cause of the malfunction is often difficult.

* Due to an engine coolant temperature sensor malfunction, the fuel injection volume is extremely high or low and engine starting trouble may occur.

* If Long FT is incorrect, there may be a fuel supply problem due to the injectors or fuel pump being clogged, etc.

* If the engine cranking speed is too high, compression loss may have occurred due to carbon interfering with the valve operation.

(b) When the malfunction (starting difficulty) can be reproduced, or malfunction conditions are known, perform the following inspections ("Problem symptoms" and "Systems to inspect")

(1) Problem symptoms

1 The engine does not crank.

HINT
The starter is normal if a noise that indicates the starter pinion gear is extending is heard. The battery may be fully depleted or there may be excess engine friction.

2 The engine cranking speed is abnormal.

HINT
If the engine cranking speed is too high (for example, 300 rpm or higher with no combustion), compression loss may have occurred because carbon interfered with valve operation, etc.

3 There is no initial combustion.

HINT
If there is no initial combustion, there is probably a wiring problem or an ignition or fuel system part malfunction.

4 The engine stalls after starter turnoff.

HINT
If the engine stalls after starter turnoff, the air-fuel ratio may be incorrect or the VVT may have a problem returning.

5 The initial combustion and starter turnoff occur late.

HINT
If the initial combustion and starter turnoff occur late, the fuel injection volume is probably incorrect (too low or too high).

HINT
Causes of fuel system malfunctions according to conditions present at the time of the malfunction.

- When 2 to 3 minutes have elapsed after stopping the engine: Fuel pressure loss due to the pressure regulator failing to maintain the fuel pressure.
- When 15 to 120 minutes have elapsed after stopping the engine: Problem with injector fuel seal.
- When a long time has elapsed after stopping the engine: Pressure regulator is stuck open.

(2) Systems to inspect.

1 Intake system

2 Ignition system

3 Fuel system

2. INSPECTION FLOW

(a) Freeze frame data exists, but the malfunction (starting difficulty) has not reoccurred and the malfunction conditions are unknown.

HINT
- *1: First combustion after cranking begins.
- *2: Condition when engine speed increases and starter can be turned off.

(b) When the malfunction (starting difficulty) can be reproduced, or when malfunction conditions are known.

(1) Problem symptoms

(2) Systems to inspect.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT AND RECORD FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(d) Read the DTCs and record the Freeze Frame Data.

HINT
- This freeze frame data shows the actual engine conditions when engine starting trouble occurred.
- When confirming the freeze frame data, be sure to check all 5 data sets of freeze frame data.
- The fourth set of freeze frame data is the data recorded when then the DTC is stored.

Result

B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.

2. CHECK ENGINE IMMOBILISER SYSTEM

(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 / Data List / All Data / Immobiliser Fuel Cut.

(e) Read the value displayed on the Techstream.

OK:

Immobiliser Fuel Cut is OFF

HINT
After reconnecting the battery cable, if the engine is started immediately (without waiting 1.8 seconds after turning the ignition switch to ON), the engine will stop (due to the key verification process). The engine can be started after that.

NG -- REPAIR ENGINE IMMOBILISER SYSTEM Engine Immobiliser System
OK -- Continue to next step.

3. CHECK MALFUNCTION CONDITION

(a) Confirm the problem symptoms.

Result

B -- CONFIRM PROBLEM SYMPTOM
A -- Continue to next step.

4. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

Result:

HINT
When DTC P1604 is stored, either "Engine Start Hesitation"*1 or "Low Rev for Eng Start"*2 in the Freeze Frame Data will be ON. If "Low Rev for Eng Start" is ON, proceed to E.

*1: This value turns ON when the engine speed does not reach a certain value for a certain period of time when starting the engine.

*2: This value turns ON when the engine stalls immediately after starting the engine. If "Low Rev for Eng Start" is ON, as there is a possibility that the low engine speed or engine stall was caused by the user, confirm the following freeze frame data items.

- Immobiliser Fuel Cut
- Engine Speed (Starter Off)
- Shift SW Status (R, D Range)

E -- CHECK MASS AIR FLOW METER

D -- CHECK FREEZE FRAME DATA

C -- CHECK FREEZE FRAME DATA

B -- CHECK FREEZE FRAME DATA

A -- CHARGE OR REPLACE BATTERY

5. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

Result:

HINT
- *1: The 5 sets of freeze frame data show approximately the same battery voltage.

- *2: The 5 sets of freeze frame data show different battery voltages.
- *3: If the voltage fluctuates, it can be determined that cranking is being performed. When the engine speed is 0 rpm, the crankshaft position sensor system and/or the ECM may be malfunctioning.
- *4: There may be excess engine friction. Make sure that the crankshaft rotates smoothly when turning it by hand. Excess engine friction may have occurred temporarily. Remove the cylinder head cover and oil pan, and check for foreign matter such as iron fragments. If there is a malfunction or signs of a malfunction present, perform a detailed inspection by disassembling all the parts.

C -- CHECK AND REPAIR ENGINE OR BATTERY

B -- CHECK SENSOR INSTALLATION

A -- CHECK STARTER SIGNAL CIRCUIT

6. CHECK SENSOR INSTALLATION

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

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

Result

B -- SECURELY REINSTALL SENSOR Installation
A -- Continue to next step.

7. CHECK CRANKSHAFT POSITION SENSOR

(a) Disconnect the crankshaft position sensor connector.

(b) Check for oil on the connector terminals.

OK:

No oil on the terminals.

NG -- REPLACE CRANKSHAFT POSITION SENSOR Removal
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (CRANKSHAFT POSITION SENSOR - ECM)

(a) Disconnect the crankshaft position 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.

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

9. CHECK CRANKSHAFT POSITION SENSOR

(a) Replace the crankshaft position sensor Removal.

(b) Check the engine start operation.

OK:

Malfunction has been repaired successfully.

NG -- REPLACE ECM Removal

OK -- END (CRANKSHAFT POSITION SENSOR IS DEFECTIVE) Removal

10. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

Result:

HINT
- *1: A long time had not elapsed after stopping the engine.
- *2: A long time had elapsed after stopping the engine.

C -- CHECK FUEL PUMP CONTROL SYSTEM

B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP / SPEED)

A -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal

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

(a) Connect the Techstream to the DLC3.

(b) Disconnect the connector from the fuel suction tube.

(c) Turn the ignition switch to ON.

(d) Using the Techstream, select the [Control the Fuel Pump / Speed] Active Test.

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

Standard Voltage:

(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:

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 FUEL INJECTOR POWER SOURCE CIRCUIT
OK -- Continue to next step.

13. 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.
- When performing the Active Test, if there is no operating noise from the fuel pump, the fuel pump system may be malfunctioning.
- Check if the vehicle ran out of fuel, as engine starting trouble due to running out of fuel is also detected.

B -- CHECK FUEL SYSTEM

A -- REPAIR OR REPLACE FUEL LINE

14. CHECK FUEL SYSTEM

(a) Check for foreign matter such as iron particles around the fuel pump (fuel pump, fuel pump filter, and inside the fuel tank), and for signs that the fuel pump was stuck.

Result

B -- PERFORM SIMULATION TEST

A -- REPAIR OR REPLACE FUEL SYSTEM

15. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

Result:

HINT
*1: Compression loss may have occurred in the engine assembly.

D -- CHECK FREEZE FRAME DATA

C -- CHECK AND REPAIR ENGINE

B -- INSPECT FUEL INJECTOR

A -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal

16. INSPECT FUEL INJECTOR

(a) Check that no carbon is stuck to the fuel injector.

OK:

No carbon present.

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

17. CHECK FUEL SYSTEM

(a) Check for foreign matter such as iron particles around the fuel pump (fuel pump, fuel pump filter, and inside the fuel tank), and for signs that the fuel pump was stuck.

Result

B -- PERFORM SIMULATION TEST

A -- REPAIR OR REPLACE FUEL SYSTEM

18. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

Result:

HINT
*1: If the engine coolant temperature is 40°C or less (after stopping the engine and the vehicle is not driven for a long period of time), 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: If the engine coolant temperature is 40 to 90°C (15 to 120 minutes have passed after stopping the engine), there may be fuel leaking from a fuel injector.

*3: If the engine coolant temperature is 90°C or more (2 to 5 minutes have passed after stopping the engine), there may be a problem with the pressure regulator failing to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.

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

19. CHECK FUEL PRESSURE

HINT
For the fuel pressure inspection, refer to the following procedures Testing and Inspection.

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

Standard:

147 kPa (1.5 kgf/cm2) or higher (5 minutes after stopping the engine)

HINT
If the engine cannot be started, read the values after cranking the engine.

Result

B -- REPLACE PRESSURE REGULATOR Removal

A -- PERFORM SIMULATION TEST

20. CHECK 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.

B -- CHECK THROTTLE BODY
A -- Continue to next step.

21. CHECK FUEL INJECTOR

(a) Inspect the fuel injectors Testing and Inspection.

Result:

B -- CHECK THROTTLE BODY

A -- REPLACE FUEL INJECTOR Removal

22. CHECK THROTTLE BODY

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

Result:

B -- CHECK INTAKE SYSTEM

A -- CLEAN OR REPLACE THROTTLE BODY Removal

23. CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leak Testing and Inspection.

OK:

No leak in intake system.

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