Part 1
2GR-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 values when there is an air leak in the intake system during starting difficulty
Freeze Frame Data P1604 Stability Malfunction
WIRING DIAGRAM
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 60 and 250 rpm (the engine cranks but there is no combustion).
HINT
If the engine speed is between 60 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 #1 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.
NOTICE:
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
* After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Service Precautions.
HINT
* Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
* Bank 1 refers to the bank that includes the No. 1 cylinder.
* Bank 2 refers to the bank that does not include the No. 1 cylinder.
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 / 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.
Text in Illustration
Result
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. CHECK ENGINE IMMOBILISER SYSTEM
HINT
If the vehicle is not equipped with a immobiliser system, proceed to next step (OK).
(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 / Data List / Immobiliser Fuel Cut.
(e) Read the value displayed on the Techstream.
OK:
Immobiliser Fuel Cut is OFF
Result
HINT
If the engine is cranked immediately after reconnecting the battery cable (key verification for immobiliser system not completed), the engine cannot be started. Key verification needs to wait for several seconds after turning the ignition switch to ON.
B -- REPAIR ENGINE IMMOBILISER SYSTEM (W/O SMART KEY SYSTEM) How To Proceed With Troubleshooting
C -- REPAIR ENGINE IMMOBILISER SYSTEM (W/ SMART KEY SYSTEM) How To Proceed With Troubleshooting
A -- Continue to next step.