DTC P0145:00 [PCM (SKYACTIV-X)]

Description	NOx sensor: Slow response (during transition from rich to lean)
Detection condition	Determination conditions	• The response speed of the NOx sensor input signal when the air/fuel ratio is changed from rich to lean is slow.
	Preconditions	• The following conditions are met: ― NOx sensor is activating ― Catalytic converter estimated temperature: specified value or more ― HO2S estimated temperature: specified value or more ― NOx sensor output lambda signal at fuel cut recovery: specified value or more • The following DTCs are not detected: ― NOx sensor: P2200:00, P2201:00, P2205:00, P220A:00 and U029D:00 ― HO2S heater: P0037:00 and P0038:00 ― MAF sensor: P0100:00, P0101:00 and U060F:00 ― ECT sensor No.1: P0117:00 and P0118:00 ― HO2S: P0137:00, P0138:00 and P0140:00
	Drive cycle	• 2
	Self test type	• CMDTC self test
	Sensor used	• NOx sensor • HO2S
Fail-safe function	• Inhibits the SPCCI control with a large amount of intake air introduced (lean A/F).
Vehicle status when DTCs are output	• Not applicable
Possible cause	• NOx sensor malfunction ― NOx sensor connector or terminals malfunction ― NOx sensor incorrect installation ― Exhaust system leakage ― TWC damaged or malfunction • NOx sensor deterioration • NOx sensor heater malfunction • Improper operation of purge control system ― Purge solenoid valve malfunction ― Improper connection of evaporative hose (purge solenoid valve side) • Engine malfunction ― Insufficient engine compression • PCM malfunction

• The PCM detects the oxygen concentration in the exhaust gas based on the NOx sensor signal. The PCM monitors the response speed of the NOx sensor relative to the oxygen concentration, and if the response speed of the NOx sensor is delayed, a DTC is stored.

1. Warm up the engine to allow the engine coolant temperature to reach 80 °C {176 °F} or more.

2. Verify that OBD information (such as freeze frame data) has been obtained and recorded.

3. Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC.)

4. Switch the ignition off.

5. Drive the vehicle for 15 min at a speed of 40 km/h {25 mph} or more.

6. Verify that the NOX_SEN_ACTIVITY is on.

7. Shift to 3rd gear and rapidly accelerate the vehicle to 60 km/h {37 mph}.

8. Release the accelerator pedal and decelerate the vehicle to 40 km/h {25 mph}.

9. Repeat Step 5 to 8 operations above 5 times.

10. Try to reproduce the malfunction by driving the vehicle for 5 min based on the values in the freeze frame data/snapshot data.

Note

• Match the engine coolant temperature in the recorded freeze frame data/snapshot data, the vehicle speed, and engine speed values to the best extent possible while driving the vehicle.

PIDs	Reference
NOX_SEN_ACTIVITY	(See PID/DATA MONITOR TABLE [PCM (SKYACTIV-X)].)

Step	Inspection	Results	Action
1	PURPOSE: RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION • Record the freeze frame data/snapshot data. Note • Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	PURPOSE: VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY • Verify related Service Bulletins, on-line repair information, or Service Information availability. • Is any related Information available?	Yes	Perform repair or diagnosis according to the available information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	PURPOSE: INSPECT FOR OTHER RELATED DTCs • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-X)].) Go to Troubleshooting Diagnostic Procedure to perform the repair completion verification.
3		No	Go to Troubleshooting Diagnostic Procedure to perform the procedure from Step 1.

• Repair completion verification

Step	Inspection	Results	Action
1	PURPOSE: INSPECT PURGE SOLENOID VALVE FOR MALFUNCTION • Inspect the applicable part. (See PURGE SOLENOID VALVE INSPECTION [SKYACTIV-X 2.0].) • Is the part normal?	Yes	Go to the next step.
1		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
2	PURPOSE: VERIFY IF DIAGNOSTIC RESULT IS AFFECTED BY MALFUNCTION RELATED TO POOR EVAPORATIVE HOSE CONNECTION • Verify the connection condition of the evaporative hose (purge solenoid valve side). (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-X 2.0].) • Is the evaporative hose (purge solenoid valve side) connection normal?	Yes	Go to the next step.
2		No	Connect evaporative hose correctly and perform the repair completion verification. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
3	PURPOSE: INSPECT NOx SENSOR CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	PURPOSE: INSPECT NOx SENSOR FOR MALFUNCTION • Inspect the applicable part. (See NOx SENSOR INSPECTION [SKYACTIV-X 2.0].) • Is the part normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See NOx SENSOR REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
5	PURPOSE: INSPECT EXHAUST SYSTEM FOR LEAKAGE • Visually inspect for exhaust gas leakage from the exhaust system. • Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
5		No	Go to the next step.
6	PURPOSE: VERIFY IF CATALYTIC CONVERTER DAMAGE AFFECTS NOx SENSOR SIGNAL • Verify if the catalytic converter is damaged. • Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification.
6		No	Replace the NOx sensor and perform the repair completion verification. (See NOx SENSOR REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
Repair completion verification 1	PURPOSE: VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Replicate the vehicle conditions at the time the DTC was detected using the following procedure. ― Implement the repeatability verification procedure. (See Repeatability Verification Procedure.) • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	PURPOSE: VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.

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