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 will be set 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 lower than 50°C
(122°F), the ECM checks the ignition timing at 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: When
the cable is disconnected from the negative battery terminal during
inspections or repairs, the ISC (Idle Speed Control) learning values are
cleared. This DTC cannot be stored with the ISC learning values
cleared. HINT: The ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.
 |
DTC No. | DTC Detection Condition |
Trouble Area | | P050B |
Insufficient ignition timing retard at cold start (2 trip detection logic) |
- Throttle with motor body assembly
- Mass air flow meter
- PCV system
- Air cleaner filter element sub-assembly
- Intake system
- VVT system
- EGR valve assembly
- ECM
- Wire harness or connector
| MONITOR STRATEGY |
Related DTCs | P050B: Cold start ignition timing performance | |
Required Sensors/Components (Main) | Throttle with motor body assembly | |
Required Sensors/Components (Related) |
Mass air flow meter Engine Coolant Temperature (ECT) sensor | |
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 following DTCs not present |
P0010, P0020 (VVT oil control valve) P0011, P0021 (VVT system - Advance)
P0012, P0022 (VVT system - Retard) P0013, P0023 (Exhaust VVT oil control valve)
P0014, P0024 (Exhaust VVT system - Advance) P0015, P0025 (Exhaust VVT system - Retard)
P0016, P0018 (VVT system - Misalignment) P0017, P0019 (Exhaust VVT system - Misalignment)
P006A, P0107, P0108 (Manifold absolute pressure) P0102, P0103 (Mass air flow meter)
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, P014E, P014F, P015A, P015B, P015C, P015D, P2195, P2196, P2197,
P2198, P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255,
P2256 (Air fuel ratio sensor) P0171, P0172, P0174, P0175 (Fuel system)
P0301 - P0308 (Misfire) P0335 (Crankshaft position sensor) P0340, P0342, P0343, P0345, P0347, P0348 (VVT sensor)
P1340 (Camshaft position sensor) P0351 - P0358 (Igniter) P0365, P0367, P0368, P0390, P0392, P0393 (Exhaust VVT sensor)
P0401 (EGR system) P0500 (Vehicle speed sensor) P219A, P219B, P219C, P219D, P219E, P219F, P21A0, P21A1, P21A2, P21A3 (Air-fuel ratio imbalance) | |
Battery voltage | 8 V or more | |
Time after engine start | 3 seconds or more | |
Starter | OFF | |
ECT at engine start | -10°C (14°F) or more | |
ECT | -10 to 50°C (14 to 122°F) | |
Engine idling time | 3 seconds or more | |
Fuel-cut | OFF | |
Vehicle speed | Less than 3 km/h (1.875 mph) | |
Atmospheric pressure | 76 kPa (570 mmHg) or more | TYPICAL MALFUNCTION THRESHOLDS |
Accumulated time when ignition timing retard is cut off |
8 seconds or more | CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON and turn the Techstream on.
- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON and turn the Techstream on [A].
- Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
- Check that "Coolant Temp" in the Data List is within the range of -10 to 50°C (14 to 122°F).
- Start the engine and warm it up until the coolant temperature is the same as the coolant temperature in the freeze frame data.
- Idle the engine for 1 minute or more.
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].
- 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.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P050B.
- Check the DTC judgment result.
|
Tester 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 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] through
[B].
- If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page
 ).
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
CAUTION / NOTICE / HINT
HINT:
- DTC P050B may be set when the engine has the symptoms listed below. If necessary, check the trouble areas listed below.
|
Symptom |
Factor |
Trouble Area |
|
Low idle speed when engine is cold (immediately after engine start)
|
Excessive engine friction |
- Engine oil deterioration
- Drive belt tension
- A/C compressor
- Generator
- Vane pump
|
|
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 ignition switch to ON.
(c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the pending DTCs. Result |
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.
(a) Connect the Techstream to the DLC3. (b) Start the engine. (c) Turn the Techstream on.
(d)
Enter the following menus: Powertrain / Engine and ECT / Data List /
Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1. (e) Read the values displayed on the Techstream.
(f) Add together the Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1 values to obtain the total fuel trim.
OK: Total of Short FT B1S1 and Long FT B1S1, or Short FT B2S1 and Long FT B2S1 values is between -20% and 20%.
| NG |
| GO TO STEP 7 |
|
OK | |
| |
| 3. |
INSPECT THROTTLE WITH MOTOR BODY ASSEMBLY (THROTTLE BODY) |
(a) Check for deposits around the throttle valve and check the throttle valve condition.
OK: No deposits around 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) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:
- When performing the Active Test, make sure the shift lever is in P or N.
- The A/C switch and all accessory switches should be off.
(c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
(e)
Confirm the Throttle Idle Position is ON and check the engine idling
condition and 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.
OK: MAP and idling condition change in response to EGR step position as follows.
Standard: |
- | EGR Step Position (Active Test) | |
0 Steps | 0 to 30 Steps | |
Idling condition | Steady idling |
Idling changes from steady to rough idling or engine stall | |
MAP (Data List) |
20 to 40 kPa (150 to 300 mmHg) |
MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed |
| OK |
| GO TO STEP 19 |
|
NG | |
| |
| 5. |
INSPECT EGR VALVE ASSEMBLY | (a) Remove the EGR valve (See page
). (b) Check if the EGR valve is stuck open.
OK: EGR valve is tightly closed.
| OK |
| GO TO STEP 19 |
| NG |
| GO TO STEP 17 |
| 6. |
REPAIR OR REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY |
(a) Repair or replace the throttle with motor body assembly (See page
). HINT: Perform "Inspection After Repair" after repairing or replacing the throttle with motor body assembly (See page
).
| NEXT | |
GO TO STEP 19 |
(a) Check the PCV hose connections (See page
). OK: PCV hose is connected correctly and is not damaged.
| NG |
| GO TO STEP 14 |
|
OK | |
| |
(a) Check the intake system for vacuum leaks (See page
). OK: No leak in the intake system.
HINT: Perform "Inspection After Repair" after repairing or replacing the intake system (See page
).
| NG | |
GO TO STEP 15 |
|
OK | |
| |
| 9. |
INSPECT 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 16 |
|
OK | |
| |
| 10. |
PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) |
(a) Connect the Techstream to the DLC3. (b) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
HINT:
- When performing the Active Test, make sure the shift lever is in P or N.
- The A/C switch and all accessory switches should be off.
(c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
(e)
Confirm the Throttle Idle Position is ON and check the engine idling
condition and 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.
OK: MAP and idling condition change in response to EGR step position as follows.
Standard: |
- | EGR Step Position (Active Test) | |
0 Steps | 0 to 30 Steps | |
Idling condition | Steady idling |
Idling changes from steady to rough idling or engine stall | |
MAP (Data List) |
20 to 40 kPa (150 to 300 mmHg) |
MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed |
| OK |
| GO TO STEP 12 |
|
NG | |
| |
| 11. |
INSPECT EGR VALVE ASSEMBLY | (a) Remove the EGR valve assembly (See page
). (b) Check if the EGR valve is stuck open.
OK: EGR valve is tightly closed.
| NG |
| GO TO STEP 17 |
|
OK | |
| |
| 12. |
PERFORM ACTIVE TEST USING TECHSTREAM | (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 inspection procedure (VVT system for intake side) (See page
). (2) Perform the Active Test, referring to DTC P0014 inspection procedure (VVT system for exhaust side) (See page
).
| NG | |
GO TO STEP 18 |
|
OK | |
| |
| 13. |
READ VALUE USING TECHSTREAM (MAF) | (a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the Techstream on. (c) Enter the following menus: Powertrain / Engine and ECT / Data List / MAF and Coolant Temp.
(d) Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
(e) Read MAF with the engine speed at 3000 rpm. Standard: Between 18.3 gm/sec. and 25.8 gm/sec. (shift lever: N; A/C: Off)
| OK |
| GO TO STEP 19 |
| NG |
| GO TO STEP 20 |
| 14. |
REPAIR OR REPLACE PCV HOSE | (a) Repair or replace the PCV hose.
| NEXT |
| GO TO STEP 19 |
| 15. |
REPAIR OR REPLACE INTAKE SYSTEM | (a) Repair or replace the intake system.
HINT: Perform "Inspection After Repair" after repairing or replacing the intake system (See page
).
| NEXT | |
GO TO STEP 19 |
| 16. |
REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY |
(a) Replace the air cleaner filter element sub-assembly.
| NEXT |
| GO TO STEP 19 |
| 17. |
REPLACE EGR VALVE ASSEMBLY | (a) Replace the EGR valve assembly (See page
). HINT: Perform "Inspection After Repair" after repairing or replacing the EGR valve assembly (See page
).
| NEXT | |
GO TO STEP 19 |
| 18. |
CHECK AND REPAIR VVT SYSTEM | (a) Check and repair the VVT system.
HINT:
- Refer to DTC P0011 Inspection Procedure (VVT system for intake side) (See page
).
- Refer to DTC P0014 Inspection Procedure (VVT system for exhaust side) (See page
).
|
NEXT | |
| |
| 19. |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
NOTICE: In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON.
(c) Turn the Techstream on. (d) Clear the DTCs (See page
). (e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on. (g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P050B. (k) Check the DTC judgment result. Result |
Result | Proceed to | |
NORMAL (DTC is not output) |
A | | ABNORMAL
(DTC P050B is output) |
B |
| A |
| CHECK FOR INTERMITTENT PROBLEMS |
|
B | |
| |
| 20. |
CHECK HARNESS AND CONNECTOR | (a)
Check the connection and terminal and terminal contact pressure of
connectors and wire harnesses between the mass air flow meter and ECM
(See page ). HINT: Repair any problems.
|
NEXT | |
| |
| 21. |
CHECK WHETHER DTC OUTPUT RECURS | NOTICE:
In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON.
(c) Turn the Techstream on. (d) Clear the DTCs (See page
). (e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on. (g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P050B. (k) Check the DTC judgment result. Result |
Result | Proceed to | |
ABNORMAL (DTC P050B is output) |
A | | NORMAL
(DTC is not output) | B |
| B |
| END |
|
A | |
| |
| 22. |
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
 (a) Disconnect the MAF meter connector.
(b) Disconnect the ECM connector. (c) Measure the resistance according to the value(s) in the table below.
Standard Resistance: |
Tester Connection | Condition |
Specified Condition | |
D7-3 (VG) - D74-74 (VG) |
Always | Below 1 Ω | |
D7-2 (E2G) - D74-75 (E2G) |
Always | Below 1 Ω | |
D7-3 (VG) or D74-74 (VG) - Body ground |
Always | 10 kΩ or higher |
| NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
OK | |
| |
| 23. |
REPLACE MASS AIR FLOW METER | (a) Replace the mass air flow meter (See page
).
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.
- Perform "Inspection After Repair" after replacing the mass air flow meter (See page
).
|
NEXT | |
| |
| 24. |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
NOTICE: In this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON.
(c) Turn the Techstream on. (d) Clear the DTCs (See page
). (e) Turn the ignition switch off and wait for at least 30 seconds.
(f) Turn the ignition switch to ON and turn the Techstream on. (g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P050B. (k) Check the DTC judgment result. Result |
Result | Proceed to | |
NORMAL (DTC is not output) |
A | | ABNORMAL
(DTC P050B is output) |
B |
| A |
| END |
| B |
| REPLACE ECM | | 
