DTC Code | DTC Name |
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P1605 | Rough Idling |
DESCRIPTION
This DTC is stored when the speed of a specific cylinder becomes low and the idle speed becomes unstable. This DTC is also stored if the vehicle runs out of fuel. Be sure to check whether there is enough fuel in the fuel tank before inspection.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
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P1605 | Rough Idling | When the accelerator pedal is fully closed and the engine is idling, the speed of a specific cylinder is low for 2 to 10 seconds. (1 trip detection logic) |
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- | DTC stored |
DTC No. | Data List |
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P1605 |
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CAUTION / NOTICE / HINT
In order to obtain stable idling, glow system operation, fuel system operation and compression sufficient to maintain the target idling speed are necessary.
Glow system
The following malfunctions may be present in the glow system.
Engine coolant temperature sensor malfunction.
Glow plug assembly malfunction.
Glow plug relay assembly malfunction.
Fuel system
The following malfunctions may be present in the fuel system.
Fuel leakage.
Problem with injector assemblies.
Problem with supply pump assembly.
Air in fuel line.
Engine assembly
The following malfunctions may be present in the engine assembly.
Insufficient compression.
In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1605 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as rough idling.
As this DTC can be stored as a result of certain user actions, even if this DTC are 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 GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data.
The fourth set of freeze frame data is the data recorded when then the DTC is stored.
*a | DTC stored |
*b | 0.5 seconds |
*c | Freeze frame data recorded point |
PROCEDURE
READ OUTPUT DTC (RECORD STORED DTC AND FREEZE FRAME DATA (PROCEDURE 1))
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Record the stored DTCs and freeze frame data.
Powertrain > Engine and ECT > Trouble CodesThis freeze frame data shows the actual engine conditions when the engine idling problem occurred.
Result | ||
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NEXT |
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1605)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
Powertrain > Engine and ECT > Trouble CodesResult | ||||||
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If any DTCs other than DTC P1605 are output, troubleshoot those DTCs first.
B |
GO TO DTC CHART Click hereНажмите здесь |
A |
DETERMINE CAUSE OF PROBLEM (CHECK FREEZE FRAME DATA AND SNAPSHOT)
Determine the cause of the problem based on the freeze frame data recorded in Procedure 1.
Judgment of Data List Values | Problem Cause | Diagnosis Note |
---|---|---|
Rough Idle #1 to #4 in the freeze frame data is ON | Injector assembly | This shows that the idle speed of this cylinder is lower than the other cylinders. |
Data List | Judgment of Data List Values | Faulty Component | Diagnosis Note |
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Injection Feedback Val #1 (to #4) |
Tip:
Read the value after one minute of idling after warm up (engine coolant temperature above 75°C [167°F]). This value is only calculated when idling. |
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Result | ||
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NEXT |
GO TO ROUGH IDLING OR EXCESSIVE ENGINE VIBRATIONS Click hereНажмите здесь |