Lexus NX manuals

Lexus NX: Cold Start Ignition Timing Performance (P050B)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (engine Control) / Sfi System / Cold Start Ignition Timing Performance (P050B)

MONITOR DESCRIPTION

This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°F). The DTC is stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the ignition timing at cold start. When the engine is started at an engine coolant temperature of less than 50°C (122°F), the ECM checks the ignition timing during engine idling. If the ignition timing advances beyond the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

NOTICE:

The idle speed control learned values are cleared by performing a learned value reset. Idle speed control learning needs to be performed before this DTC can be stored.

HINT:

Idle speed control learning* is performed when the engine is warmed up and has been idling for 5 minutes.

*: Refer to Initialization.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P050B

Cold Start Ignition Timing Performance

Insufficient ignition timing retard at cold start (2 trip detection logic).
  • Throttle body with motor assembly
  • Mass air flow meter sub-assembly
  • PCV system
  • Air cleaner filter element sub-assembly
  • Intake system
  • VVT system
  • EGR valve assembly
  • Wire harness or connector
  • ECM

Comes on

DTC stored

MONITOR STRATEGY

Related DTCs

P050B: Cold start ignition timing performance

Required Sensors/Components (Main)

Throttle body with motor assembly

Required Sensors/Components (Related)

Engine coolant temperature sensor

Mass air flow meter sub-assembly

Frequency of Operation

Once per driving cycle

Duration

10 seconds

MIL Operation

2 driving cycles

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

P0010 (Camshaft timing oil control valve)

P0011 (VVT system - advance)

P0012 (VVT system - retard)

P0016 (VVT system - misalignment)

P0102, P0103 (Mass air flow meter)

P0107, P0108 (Manifold absolute pressure)

P0115, P0117, P0118 (Engine coolant temperature sensor)

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle position sensor)

P0125 (Insufficient coolant temperature for closed loop fuel control)

P014C, P014D, P015A, P015B, P2195, P2196, P2237, P2238, P2239, P2252, P2253 (Air fuel ratio sensor)

P0171, P0172 (Fuel system)

P0300, P0301, P0302, P0303, P0304 (Misfire)

P0335 (Crankshaft position sensor)

P0340 (Camshaft position sensor)

P0340, P0342, P0343 (VVT sensor)

P0351, P0352, P0353, P0354 (Igniter)

P0401 (EGR system)

P219A, P219C, P219D, P219E, P219F (Air-fuel ratio imbalance)

Auxiliary battery voltage

8 V or higher

Time after engine start

3 seconds or more

Starter

Off

Engine coolant temperature at engine start

-10°C (14°F) or higher

Engine coolant temperature

-10°C (14°F) or higher, and less than 50°C (122°F)

Fuel-cut

Off

Vehicle speed

Less than 60 km/h (37.5 mph)

Atmospheric pressure

76 kPa(abs) [570 mmHg(abs)] or higher

TYPICAL MALFUNCTION THRESHOLDS

Accumulated time when ignition timing retard is cut off

8 seconds or more

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the power switch off and wait for at least 30 seconds.
  5. Turn the power switch on (IG) and turn the Techstream on.
  6. Put the engine in inspection mode (maintenance mode).

    Click here

  7. Start the engine and warm it up for 5 minutes or more.
  8. Stop the engine.
  9. Leave the vehicle outside overnight.
  10. Turn the power switch on (IG) and turn the Techstream on [A].
  11. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.
  12. Check that "Coolant Temp" in the Data List is within the range of -10 to 50°C (14 to 122°F).
  13. Put the engine in inspection mode (maintenance mode).

    Click here

  14. Start the engine and warm it up until the coolant temperature is the same as the coolant temperature in the freeze frame data.
  15. Idle the engine for 1 minute or more [B].
  16. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  17. Read the pending DTC.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  18. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  19. Input the DTC: P050B.
  20. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System normal

    ABNORMAL
    • DTC judgment completed
    • System abnormal

    INCOMPLETE
    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A
    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, idle the engine for 3 minutes, let the engine cool down, and then perform steps [A] and [B].
  21. If no pending DTC is output, perform a universal trip and check for permanent DTCs.

    Click here

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0102.

Click here

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

  • DTC P050B may be set when the engine has the symptoms listed below. If necessary, check the trouble areas listed below.

    Symptoms

    Factor

    Trouble Area

    Low idle speed when engine is cold

    (immediately after engine start)

    Excessive engine friction
    • Engine oil deterioration
    • Drive belt tension

    Rough idle when engine is cold

    (immediately after engine start)

    Abnormal combustion

    Fuel quality
  • 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 be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P050B)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

DTC P050B is output

A

DTC P050B and other DTCs are output

B

HINT:

If any DTCs other than P050B are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

2.

READ VALUE USING TECHSTREAM (FUEL TRIM)

HINT:

Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter sub-assembly.

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(e) Start the engine.

(f) Enter the following menus: Powertrain / Engine and ECT / Data List / Gas AF Control / Short FT B1S1 and Long FT B1S1.

Powertrain > Engine and ECT > Data List

Tester Display

Short FT B1S1

Long FT B1S1

(g) Read the values displayed on the Techstream at engine idle.

(h) Add together the Short FT B1S1 and Long FT B1S1 values to obtain the total fuel trim.

Standard:

The total of the Short FT B1S1 and Long FT B1S1 values is between -20% and 20%.

NG

GO TO STEP 7

OK

3.

INSPECT THROTTLE BODY WITH MOTOR ASSEMBLY (THROTTLE VALVE)

(a) Inspect that there are no deposits around the throttle valve and throttle valve condition.

OK:

No deposits around the throttle valve and throttle valve moves smoothly.

NG

GO TO STEP 6

OK

4.

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(e) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

HINT:

The A/C switch and all accessory switches should be off.

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Primary / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display

Control the EGR Step Position

Data List Display

MAP

Throttle Idle Position

(g) Confirm that the Throttle Idle Position is ON and check the MAP values in the Data List while performing the Active Test.

HINT:

  • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
  • Be sure to return the EGR valve to step 0 when the Active Test is completed.
  • Do not open the EGR valve 30 steps or more during the Active Test.

OK:

MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard:

-

EGR Step Position (Active Test)

0 Steps

0 to 30 Steps

MAP

(Data List)

(EGR valve is fully closed)

MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

HINT:

  • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
  • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
OK

GO TO STEP 14

NG

5.

INSPECT EGR VALVE ASSEMBLY

(a) Remove the EGR valve assembly.

Click here

(b) Check if the EGR valve is stuck open.

OK:

EGR valve is tightly closed.

OK

GO TO STEP 14

NG

GO TO STEP 16

6.

REPAIR OR REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY

(a) Repair or replace the throttle body with motor assembly.

Click here

HINT:

Perform "Inspection After Repair" after replacing the throttle body with motor assembly.

Click here

NEXT

GO TO STEP 20

7.

CHECK PCV SYSTEM

(a) Check the PCV hose connections.

Click here

OK:

PCV valve and hose are connected correctly and are not damaged.

NG

GO TO STEP 19

OK

8.

CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks.

Click here

OK:

No leaks from intake system.

NG

GO TO STEP 18

OK

9.

CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Visually check that the air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

OK:

The air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil.

NG

GO TO STEP 17

OK

10.

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(e) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

HINT:

The A/C switch and all accessory switches should be off.

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Primary / MAP and Throttle Idle Position.

Powertrain > Engine and ECT > Active Test

Active Test Display

Control the EGR Step Position

Data List Display

MAP

Throttle Idle Position

(g) Confirm that the Throttle Idle Position is ON and check the MAP values in the Data List while performing the Active Test.

HINT:

  • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
  • Be sure to return the EGR valve to step 0 when the Active Test is completed.
  • Do not open the EGR valve 30 steps or more during the Active Test.

OK:

MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.

Standard:

-

EGR Step Position (Active Test)

0 Steps

0 to 30 Steps

MAP

(Data List)

(EGR valve is fully closed)

MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

HINT:

  • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.
  • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.
OK

GO TO STEP 12

NG

11.

INSPECT EGR VALVE ASSEMBLY

(a) Remove the EGR valve assembly.

Click here

(b) Check if the EGR valve is stuck open.

OK:

EGR valve is tightly closed.

NG

GO TO STEP 16

OK

12.

PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE VVT LINEAR)

(a) Operate the VVT system through the Active Test, and check if the VVT system is operating normally.

(1) Perform the Active Test, referring to DTC P0011 procedure.

Click here

NG

GO TO STEP 15

OK

13.

READ VALUE USING TECHSTREAM (MAF)

Click here

NG

GO TO STEP 21

OK

14.

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs

(e) Turn the power switch off and wait for at least 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(j) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

(k) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(l) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness

(m) Input the DTC: P050B.

(n) Check the DTC judgment result.

Result

Proceed to

NORMAL

(DTCs are not output)

A

ABNORMAL

(DTC P050B is output)

B
A

CHECK FOR INTERMITTENT PROBLEMS

B

GO TO STEP 21

15.

CHECK AND REPAIR VVT SYSTEM

(a) Check and repair the VVT system.

HINT:

Refer to DTC P0011 Procedure.

Click here

NEXT

GO TO STEP 20

16.

REPLACE EGR VALVE ASSEMBLY

(a) Replace the EGR valve assembly.

Click here

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

Click here

NEXT

GO TO STEP 20

17.

REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Replace the air cleaner filter element sub-assembly.

NEXT

GO TO STEP 20

18.

REPAIR OR REPLACE INTAKE SYSTEM

(a) Repair or replace the intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Click here

NEXT

GO TO STEP 20

19.

REPAIR OR REPLACE PCV HOSE

(a) Repair or replace the PCV valve or hose.

NEXT

20.

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs

(e) Turn the power switch off and wait for at least 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(j) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

(k) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(l) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness

(m) Input the DTC: P050B.

(n) Check the DTC judgment result.

Result

Proceed to

NORMAL

(DTCs are not output)

A

ABNORMAL

(DTC P050B is output)

B
A

END
B

21.

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)

(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Click here

HINT:

Repair any problems.

NEXT

22.

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs

(e) Turn the power switch off and wait for at least 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(j) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

(k) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(l) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness

(m) Input the DTC: P050B.

(n) Check the DTC judgment result.

Result

Proceed to

ABNORMAL

(DTC P050B is output)

A

NORMAL

(DTCs are not output)

B
B

END
A

23.

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

Click here

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

24.

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

(a) Replace the mass air flow meter sub-assembly.

Click here

HINT:

  • If the result of the inspection performed in step 13 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
  • Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

    Click here

NEXT

25.

CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)

NOTICE:

In this operation, the engine must be cold (approximately the same as the engine coolant temperature recorded in the freeze frame data).

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

Click here

Powertrain > Engine and ECT > Clear DTCs

(e) Turn the power switch off and wait for at least 30 seconds.

(f) Turn the power switch on (IG) and turn the Techstream on.

(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

Powertrain > Engine and ECT > Data List

Tester Display

Coolant Temp

(h) Check that the engine coolant temperature is between -10 and 50°C (14 and 122°F).

(i) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(j) Start the engine and warm it up until the engine coolant temperature is the same as the engine coolant temperature in the freeze frame data.

(k) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(l) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

Powertrain > Engine and ECT > Utility

Tester Display

All Readiness

(m) Input the DTC: P050B.

(n) Check the DTC judgment result.

Result

Proceed to

NORMAL

(DTCs are not output)

A

ABNORMAL

(DTC P050B is output)

B
A

END
B

REPLACE ECM

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