Part 1
1GR-FE ENGINE CONTROL SYSTEM: 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, 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.
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 this DTC can be stored as a result of certain user actions, even if this DTC is output, if the customer makes no mention of problems, clear this DTC without performing any troubleshooting and return the vehicle to the customer.
* If any other DTCs are output, perform troubleshooting for those DTCs first.
* 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 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, confirm the following details of the problem symptom and inspect the systems listed below.
(1) Problem Symptoms
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.
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.
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.
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.
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 fuel 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: Fuel pressure regulator is stuck open.
(2) Systems to Inspect
Intake system
Ignition system
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 FOR 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 the DTC is stored.
Result
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. CHECK MALFUNCTION CONDITION
(a) Confirm the problem symptoms.
Result
B -- CONFIRM PROBLEM SYMPTOM
A -- Continue to next step.
3. 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.
* Engine Speed (starter off)
* Shift SW Status (R, D)
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
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
* *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 CRANKSHAFT POSITION SENSOR (SENSOR INSTALLATION)
A -- CHECK STARTER SIGNAL CIRCUIT Component Tests and General Diagnostics
5. CHECK CRANKSHAFT POSITION SENSOR (SENSOR INSTALLATION)
(a) Check the tightening torque 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.
6. 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.
7. 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.
8. 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)
9. 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 CIRCUIT Component Tests and General Diagnostics
B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP / SPEED)
A -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
10. 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) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
(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 -- REPAIR FUEL PUMP CONTROL CIRCUIT Component Tests and General Diagnostics
OK -- Continue to next step.
11. CHECK TERMINAL VOLTAGE (FUEL INJECTOR POWER SOURCE)
(a) Disconnect the fuel injector assembly connectors.
(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 FUEL INJECTOR POWER SOURCE CIRCUIT
OK -- Continue to next step.
12. 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) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
(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
13. 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
14. 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
*: Compression loss may have occurred in the engine assembly.
D -- CHECK FREEZE FRAME DATA
C -- CHECK AND REPAIR ENGINE ASSEMBLY
B -- INSPECT FUEL INJECTOR ASSEMBLY
A -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
15. INSPECT FUEL INJECTOR ASSEMBLY
(a) Check that no carbon is stuck to the fuel injector assembly.
OK:
No carbon present.
NG -- REPLACE FUEL INJECTOR ASSEMBLY Removal
OK -- Continue to next step.
16. 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
17. 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 has not been driven for a long period of time), the fuel pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability of the system 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 fuel pressure regulator failing to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability of the fuel pressure regulator to maintain fuel pressure after stopping the engine.
B -- CHECK FUEL INJECTOR ASSEMBLY
A -- Continue to next step.
18. 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.
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 FUEL PRESSURE REGULATOR ASSEMBLY Removal
A -- PERFORM SIMULATION TEST
19. 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 more, a fuel injector assembly may have a sealing problem.
B -- CHECK THROTTLE BODY WITH MOTOR ASSEMBLY
A -- Continue to next step.
20. CHECK FUEL INJECTOR ASSEMBLY
(a) Inspect the fuel injector assemblies Testing and Inspection.
Result
B -- CHECK THROTTLE BODY WITH MOTOR ASSEMBLY
A -- REPLACE FUEL INJECTOR ASSEMBLY Removal
21. CHECK THROTTLE BODY WITH MOTOR ASSEMBLY
(a) Check if carbon is in the airflow passage.
Result
B -- CHECK INTAKE SYSTEM
A -- CLEAN OR REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY Removal
22. CHECK INTAKE SYSTEM
(a) Check the intake system for vacuum leaks Intake System.
OK:
No leaks in intake system.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
23. PERFORM SIMULATION TEST
(a) Check if the engine can be started.
Result
B -- CONFIRM PROBLEM SYMPTOM
A -- END
24. CONFIRM PROBLEM SYMPTOM
(a) Confirm the problem symptoms.
HINT
The problem symptoms below can be determined by reading the freeze frame data.
Result
HINT
* If there is hesitation (cranking speed is slow and combustion occurs before passing TDC) during the initial cranking period, the battery charge may be insufficient or the starter may be malfunctioning.
* *1: If there is no initial combustion, a wire harness may be malfunctioning, or the ignition or fuel system may be malfunctioning.
* *2: If the engine stalls after starter turnoff, the air-fuel ratio may be incorrect or the camshaft timing oil control valve assembly may have a problem returning.
* *3: If the initial combustion and starter turnoff occur late, the fuel injection volume may be incorrect (too low or too high).
E -- INSPECT ENGINE COOLANT TEMPERATURE SENSOR
D -- CHECK MASS AIR FLOW METER
C -- CHECK FUEL INJECTOR ASSEMBLY
B -- PERFORM SIMULATION TEST
A -- Continue to next step.
25. PERFORM SIMULATION TEST
(a) When cranking the engine, check for a noise indicating that the starter pinion gear is extending, and check that the starter pinion gear is not spinning freely.
Result
HINT
*: The battery may be fully depleted or there may be excess engine friction.
C -- INSPECT BATTERY
B -- CHECK STARTER ASSEMBLY
A -- Continue to next step.