DESCRIPTION
This DTC is stored if engine output decreases due to a malfunction in the intake or exhaust system, fuel system or cooling system.
Using the GTS, 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.
| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
|---|---|---|
| - | With the accelerator pedal fully depressed, engine output decreases for approximately 4 to 10 seconds due to a broken component in the intake or exhaust system, fuel system or cooling system or malfunction in one of those systems. (1 trip detection logic) |
|
INSPECTION PROCEDURE
Tech Tips
In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1608 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as engine lack of power on hesitation.
As the DTC can be stored as a result of certain user actions, even if the DTC is output, if the customer makes no mention of problems, clear the 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 the DTC is stored.
PROCEDURE
DTC OUTPUT (RECORD STORED DTC AND FREEZE FRAME DATA (PROCEDURE 1))
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Engine and ECT / Trouble Codes.
Record the stored DTC and freeze frame data.
Tech Tips
This freeze frame data shows the actual engine conditions when the lack of power occurred.
| NEXT |
|
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1608)
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Engine and ECT / Trouble Codes.
Read the DTCs.
| Result | Proceed to |
|---|---|
| P1608 is output | A |
| P1608 and other DTCs are output | B |
Tech Tips
If any DTCs other than DTC P1608 are output, troubleshoot those DTCs first.
| B |
|
GO TO DTC CHART Click here |
| 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 | Trouble Area | Diagnosis Note |
|---|---|---|---|
| "MAF Low" in freeze frame data is ON | Intake air volume introduced via the mass air flow meter is insufficient and fuel injection volume remains suppressed |
|
Tech Tips Refer to Lack of Power or Hesitation for the inspection procedure Click here. |
| Judgment of Data List Values | Problem Cause | Trouble Area | Diagnosis Note |
|---|---|---|---|
| "Boost Pressure Low" in freeze frame data is ON | Actual boost pressure is lower than the target boost pressure and fuel injection volume remains suppressed |
|
The possible malfunctioning areas can be narrowed down by checking "MAF/Estimate MAF Ratio" when "Boost Pressure Low" in the freeze frame data is ON Tech Tips Refer to Lack of Power or Hesitation for the inspection procedure Click here. |
| Judgment of Data List Values | Problem Cause | Trouble Area | Diagnosis Note |
|---|---|---|---|
| "MAF/Estimate MAF Ratio" in freeze frame data is 1.4 or more | Air that has passed through the mass air flow meter leaks, and the estimated intake air volume becomes less than the actual intake air volume. | Intake air leak due to intake pipe disconnection or cracks between the turbocharger sub-assembly and intercooler assembly or between the intercooler assembly and intake manifold. |
Tech Tips Refer to Lack of Power or Hesitation for the inspection procedure Click here. |
| "MAF/Estimate MAF Ratio" in freeze frame data is below 0.6 | Air that has not passed through the mass air flow meter is supplied to the engine, and the actual intake air volume becomes less than the estimated intake air volume. | Air entering due to intake pipe disconnection or cracks between the turbocharger sub-assembly and intercooler assembly or between the intercooler assembly and intake manifold. |
| Judgment of Data List Values | Problem Cause | Trouble Area | Diagnosis Note |
|---|---|---|---|
| "Common Rail Pressure Low" in freeze frame data is ON | Common rail pressure remains below the target value. |
|
Tech Tips Refer to Lack of Power or Hesitation for the inspection procedure Click here. |
| Judgment of Data List Values | Problem Cause | Trouble Area | Diagnosis Note |
|---|---|---|---|
| "Engine Coolant Temp High" in freeze frame data is ON | Coolant temperature remains high (overheating) and fuel injection volume remains suppressed. |
|
Cooling system including radiator assembly |
Tech Tips
Perform the next inspection if there are no problems with the above items.
| NEXT |
|
GO TO LACK OF POWER OR HESITATION Click here