SFI SYSTEM, Diagnostic DTC:P160500

DTC Code DTC Name
P160500 Rough Idling

DESCRIPTION

This DTC is stored if the combustion state of any cylinder is unstable.

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.

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

DTC No. Detection Item DTC Detection Condition MIL Memory Note
P160500 Rough Idling

When idling with the accelerator pedal released and the vehicle stopped, this item detects when the combustion is worsening at predetermined levels from the changes in engine speed between the cylinders.

Detection for 2 to 10 seconds according to the combustion state.

(1 trip detection logic).

 Does not come on DTC stored

SAE Code:

P1605
Trouble Area
Ignition system

  • Spark plug

  • No. 1 Ignition coil
Fuel system

  • Fuel injector assembly

  • Fuel pump (for low pressure side)

  • Fuel pump assembly (for high pressure side)

  • Fuel pump control circuit

  • Fuel line

  • Purge VSV system

  • Fuel quality (existence of foreign matter, degradation)
Intake and exhaust systems

  • Mass air flow meter

  • Intake system

    (Air leaks or deposit accumulation)

  • Throttle body with motor assembly

  • Air fuel ratio sensor (sensor 1)

  • Air fuel ratio sensor (sensor 2)*1

  • Heated oxygen sensor*2

  • Cam timing oil control solenoid assembly (intake or exhaust camshaft)

  • VVT system (Variable Valve Timing system)
Other control systems

  • ECM

  • Wire harness or connector

  • Knock sensor

  • Engine coolant temperature sensor
Engine

  • Water inlet with thermostat sub-assembly

  • Engine assembly
High load from another system

  • Air conditioning system

  • Power steering system

  • Electrical load signal system

  • CVT system

CAUTION / NOTICE / HINT

Tech Tips


  • DTC P160500


    • In contrast to conventional DTCs for components, circuits and systems, DTC P160500 is used to estimate the malfunctioning area from problem symptoms and freeze frame data in response to symptoms such as "rough idling", "strong engine vibrations", etc.

      Such problem symptoms can occur even in the following conditions:


      • Driving with long-stored fuel (fuel that has remained in the tank for long periods of time)

      • Using fuel not acclimated to the climate during a change of seasons

      • Temporarily using low-quality fuel (fuel that contains water or has poor fuel properties)

    • As DTCs may be stored when an Active Test or learning is performed, make sure to clear the DTCs before returning the vehicle to the customer.


    • If any other DTCs are output, perform troubleshooting for those DTCs first.

  • FREEZE FRAME DATA


    • Read freeze frame data using the GTS. 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 multi freeze frame data.

      Click here

    • When confirming the freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.

    • Try to operate 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 the data when the engine is idling (engine warmed up, no load, and shift lever in D or N) and compare this data with the freeze frame data.

  • PRECAUTIONS


    • Inspections take into account the fact that the malfunction may not have recurred and place emphasis on checking the vehicle conditions present at the time when the malfunction occurred.

    • When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.

PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Trouble Codes.


      Powertrain > Engine > Trouble Codes

    5. Read the DTCs.

      Result
      Result Proceed to
      Only DTC P160500 is output A
      DTCs other than P160500 are output B

      Tech Tips


      • If any DTCs other than P160500 are output, troubleshoot those DTCs first.

      • Using freeze frame data, confirm the conditions the moment the DTC was stored and after the DTC was stored. This information can be useful when troubleshooting.


    B

    GO TO DTC CHART Click here

    A

  2. READ FREEZE FRAME DATA


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Using the GTS, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored.

      Click here

      Result
      Freeze Frame Data Item for DTC P160500 Suspected Area Action Proceed to

      • Rough Idle Cylinder #1 to #4

      • Plural Cylinders Rough Idle

      		 Compression Leakage Count

      "One of Rough Idle Cylinder #1 to #4 is ON"

      and

      "Plural Cylinders Rough Idle is OFF"

      		 4 or less

      • Spark plug

      • No. 1 Ignition coil

      • Fuel injector assembly

      		 Go to ROUGH IDLING (from step 7) A
      Plural Cylinders Rough Idle is ON 4 or less

      • Mass air flow meter

      • Fuel injector assembly

      • Fuel system (low or high pressure)

      • Air fuel ratio sensor (sensor 1)

      		 Go to ROUGH IDLING (from step 15) B

      "One of Rough Idle Cylinder #1 to #4 are ON"

      or

      "Plural Cylinders Rough Idle is ON"

      		 5 or more Pressure loss from valve damage, deposits jamming the valve etc. Check compression and clean deposits in combustion chamber and intake system. C

    B

    DETERMINE CAUSE OF MALFUNCTION FOR MULTIPLE OR ALL CYLINDERS Click here

    C

    PERFORM ACTIVE TEST USING GTS (CHECK THE CYLINDER COMPRESSION) Click here

    A

  3. DETERMINE CAUSE OF MALFUNCTION FOR INDIVIDUAL CYLINDER


    1. Perform troubleshooting from Rough Idling step 7 (PERFORM ACTIVE TEST USING GTS (CHECK THE CYLINDER COMPRESSION)) and onward.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO ROUGH IDLING Click here

  4. DETERMINE CAUSE OF MALFUNCTION FOR MULTIPLE OR ALL CYLINDERS


    1. Perform troubleshooting from Rough Idling step 15 (READ VALUE USING GTS (MASS AIR FLOW SENSOR)) and onward.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    GO TO ROUGH IDLING Click here

  5. PERFORM ACTIVE TEST USING GTS (CHECK THE CYLINDER COMPRESSION)


    1. Warm up the engine.

    2. Turn the ignition switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

    6. Enter the following menus: Powertrain / Engine / Active Test / Check the Cylinder Compression / Data List / Compression / Engine Speed Cylinder #1 to #4 and Average Engine Speed of All Cylinder.


      Powertrain > Engine > Active Test
      Active Test Display
      Check the Cylinder Compression
      Data List Display
      Engine Speed Cylinder #1
      Engine Speed Cylinder #2
      Engine Speed Cylinder #3
      Engine Speed Cylinder #4
      Average Engine Speed of All Cylinder

      Tech Tips

      To display the entire Data List, press the pull down menu button next to Primary. Then select Compression.

    7. While the engine is not running, press the button to change Check the Cylinder Compression to "Start".

      Tech Tips

      After performing the above procedure, Check the Cylinder Compression will start. Fuel injection for all cylinders is prohibited and each cylinder engine speed measurement enters standby mode.

    8. Crank the engine for about 10 seconds.

    9. Monitor the engine speed (Engine Speed Cylinder #1 to #4 and Average Engine Speed of All Cylinder) displayed on the GTS.

      Tech Tips

      At first, the GTS displays extremely high cylinder engine speed values. After approximately 10 seconds of engine cranking, each cylinder engine speed measurement will change to the actual engine speed.

      Note


      • Do not crank the engine continuously for 20 seconds or more.

      • If it is necessary to crank the engine again after Check the Cylinder Compression has been changed to "Start" and the engine has been cranked once, press Exit to return to the Active Test menu screen. Then change Check the Cylinder Compression to "Start" and crank the engine.

      • Use a fully-charged battery.

    10. Stop cranking the engine, and then change "Check the Cylinder Compression" to "Stop" after the engine stops.

      Note


      • If the Active Test is changed to "Stop" while the engine is being cranked, the engine will start.

      • When performing the Active Test, DTC P160400 (Startability Malfunction) may be stored.

      • After performing the Active Test, make sure to check and clear DTCs.

    11. Read the value.

      Tech Tips


      • If the value of Data List item "Engine Speed Cylinder #1 to #4" of a cylinder is higher than other cylinders, the cylinder may be malfunctioning.

      • If the value of Data List item "Engine Speed Cylinder #1 to #4" is high for only one cylinder, compression loss is suspected.

      Result
      Result Proceed to

      There is no variation in "Engine Speed Cylinder #1 to #4"

      (All cylinders display approximately the same value for "Engine Speed Cylinder #1 to #4")

      		 A

      There is variation in "Engine Speed Cylinder #1 to #4"

      (Only one cylinder displays a value for "Engine Speed Cylinder #1 to #4" that differs considerably)

      		 B

    A

    CLEAN OFF ANY DEPOSITS

    B

  6. CHECK CYLINDER COMPRESSION PRESSURE


    1. Measure the cylinder compression pressure. If the compression pressure of a cylinder is low, inspect the engine assembly and repair or replace parts as necessary.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    END