P050B
3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P050B: Cold Start Ignition Timing Performance
DTC P050B - Cold Start Ignition Timing Performance
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 set when the malfunction is detected in consecutive driving cycles (2 tip detection logic).
NOTE: When the negative battery terminal is disconnected during inspections or repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC cannot be set with the ISC learning values cleared.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
INSPECTION PROCEDURE
HINT:
- DTC P050B may be set when the engine has the symptoms listed below. If necessary, check the trouble areas listed below.
- Read freeze frame data using 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 running or stopped, 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 Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result
HINT: If any DTCs other than P050B are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART
A -- Continue to next step.
2. READ VALUE OF TECHSTREAM (FUEL TRIM)
HINT: Calculate the total fuel trim values to check the characteristic deviation of the mass air flow meter.
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2.
(e) Read the values displayed on the tester.
(f) Add together the Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values to obtain the total fuel trim.
OK:
Total of Short FT #1 and Long FT #1, or Short FT #2 and Long FT #2 values is between -20% and 20%.
NG -- PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV)
OK -- Continue to next step.
3. CHECK THROTTLE BODY
(a) Check that there are no deposits around the throttle valve.
OK:
No deposits around the throttle valve.
NG -- REPAIR OR REPLACE THROTTLE BODY
OK -- Continue to next step.
4. REPLACE ECM
(a) Replace the ECM (Components).
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
5. PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE OCV)
(a) Connect Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1) or Control the VVT System (Bank 2).
(e) Check the engine speed while operating the Oil Control Valve (OCV) using the tester.
OK:
NG -- CHECK AIR INDUCTION SYSTEM
OK -- Continue to next step.
6. CHECK PCV HOSE CONNECTIONS
OK:
PCV hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE PCV SYSTEM
OK -- Continue to next step.
7. CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
(a) Visually check that the air cleaner filter element is not excessively contaminated with dirt or oil.
OK:
The air cleaner filter element is not excessively contaminated with dirt or oil.
NG -- REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
OK -- Continue to next step.
8. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leaks (On-Vehicle Inspection).
OK:
No leakage from the air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
9. REPLACE MASS AIR FLOW METER
(a) Replace the mass air flow meter.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
10. REPAIR OR REPLACE THROTTLE BODY
(a) Repair or replace the throttle body (Components).
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
11. CHECK AND REPAIR VVT SYSTEM
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
12. REPAIR OR REPLACE PCV SYSTEM
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
13. REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
14. REPAIR OR REPLACE AIR INDUCTION SYSTEM
NEXT -- Continue to next step.
15. CHECK WHETHER DTC OUTPUT RECURS (DTC P050B)
NOTE: For this operation, the engine must be cold (the same level as the engine coolant temperature recorded in the freeze frame data).
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Clear the DTCs (DTC Check / Clear).
(e) Switch the ECM from normal mode to check mode using the tester (Check Mode Procedure).
(f) Idle it for one minute.
(g) Check that the idling is stable and fast.
OK:
Stable fast idle
(h) Read the DTCs.
OK:
No DTC output.
NEXT -- END