DTC P2270

DTC P2270	HO2S signal stuck lean
DETECTION CONDITION	The PCM monitors the input voltage from the HO2S when the following conditions are met. If the input voltage is less than 0.4 V for 40 s , the PCM determines that the HO2S signal remains lean. MONITORING CONDITIONS ECT: more than 70°C {158°F} Engine speed: more than 1, 500 rpm MAF amount: more than 10 g/s {1.32 lb/min} Short term fuel trim: -20-20% Long term fuel trim: -50-50% Target A/F feedback system status: feedback control Diagnostic support note This is an intermittent monitor (A/F sensor, HO2S). The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle. FREEZE FRAME DATA (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	Loose installation of HO2S Leakage exhaust gas HO2S malfunction Purge solenoid valve malfunction AIR system malfunction Fuel line pressure malfunction Leakage fuel Fuel pump unit malfunction Pressure regulator (built-in fuel pump unit) malfunction Ignition system malfunction High-tension lead malfunction Incorrect power supply to ignition coil Ignition coil malfunction Insufficient compression Metering oil pump malfunction Engine oil condition malfunction Increased oil pressure Oil passage malfunction Engine malfunction Fuel injector malfunction Leakage engine coolant PCM malfunction

HO2S signal stuck lean

DETECTION CONDITION

The PCM monitors the input voltage from the HO2S when the following conditions are met. If the input voltage is less than 0.4 V for 40 s , the PCM determines that the HO2S signal remains lean.

MONITORING CONDITIONS

ECT: more than 70°C {158°F}
Engine speed: more than 1, 500 rpm
MAF amount: more than 10 g/s {1.32 lb/min}
Short term fuel trim: -20-20%
Long term fuel trim: -50-50%
Target A/F feedback system status: feedback control

Diagnostic support note

This is an intermittent monitor (A/F sensor, HO2S).
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

Loose installation of HO2S
Leakage exhaust gas
HO2S malfunction
Purge solenoid valve malfunction
AIR system malfunction
Fuel line pressure malfunction
- Leakage fuel
- Fuel pump unit malfunction
- Pressure regulator (built-in fuel pump unit) malfunction
Ignition system malfunction
- High-tension lead malfunction
- Incorrect power supply to ignition coil
- Ignition coil malfunction
Insufficient compression
- Metering oil pump malfunction
- Engine oil condition malfunction
- Increased oil pressure
- Oil passage malfunction
- Engine malfunction
Fuel injector malfunction
Leakage engine coolant
PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2) Is the DTC P2270 on FREEZE FRAME DATA (Mode 2)?	Yes	Go to the next step.
1		No	Go to the troubleshooting procedure for DTC on FREEZE FRAME DATA (Mode 2). (See DTC TABLE ).
2	VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED Have the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
2		No	Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
3	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
3		No	Go to the next step.
4	VERIFY RELATED PENDING CODE OR STORED DTC Turn the ignition switch off, then to the ON position (engine off). Verify the related PENDING CODE or stored DTCs. Are other DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE ).
4		No	Go to the next step.
5	INSPECT HO2S Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION ). Is there any malfunction?	Yes	Inspect the following: Loose installation of HO2S Exhaust gas leakage between TWC and HO2S If there is no malfunction detected, replace the HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION ). If there is a malfunction detected, repair or replace the malfunctioning part according to the inspection results. Go to Step 21.
5		No	Go to the next step.
6	INSPECT PURGE SOLENOID VALVE Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION ). Is there any malfunction?	Yes	Replace the purge solenoid valve, then go to Step 21.
6		No	Go to the next step.
7	INSPECT AIR SYSTEM OPERATION Perform the Secondary Air Injection (AIR) System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Does the AIR system operate property?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
8	INSPECT FUEL LINE PRESSURE Perform the "FUEL LINE PRESSURE INSPECTION". (See FUEL LINE PRESSURE INSPECTION ). Is there any malfunction?	Yes	Go to the next step.
8		No	Go to Step 10.
9	INSPECT FUEL SYSTEM FOR FUEL LEAKAGE Visually inspect fuel leakage in the fuel system. Is there fuel leakage?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 21.
9		No	Replace the fuel pump unit, then go to Step 21. (See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
10	INSPECT IGNITION COIL OPERATION AND HIGH-TENSION LEAD WITH TIMING LIGHT Inspect the Winking condition on each high-tension lead using timing light at idle. Do all high-tension leads show blinking condition?	Yes	Go to Step 14.
10		No	Go to the next step.
11	INSPECT HIGH-TENSION LEAD OF NO BLINKING HIGH-TENSION LEAD Inspect the high-tension leads. (See HIGH-TENSION LEAD INSPECTION ). Is there any malfunction?	Yes	Replace the malfunctioning high-tension lead, then go to Step 21. (See HIGH-TENSION LEAD REMOVAL/INSTALLATION ).
11		No	Go to the next step.
12	INSPECT IGNITION COIL POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND Turn the ignition switch to the ON position (engine off). Measure the voltage between ignition coil terminal C (wiring harness-side) and body ground. Is the voltage B+ ?	Yes	Go to the next step.
12		No	Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 21.
13	INSPECT IGNITION COIL Inspect the ignition coil. (See IGNITION COIL INSPECTION ). Is there any malfunction?	Yes	Replace the ignition coil, then go to Step 21. (See IGNITION COIL REMOVAL/INSTALLATION ).
13		No	Inspect for open circuit in wiring harness between ignition coil terminal B and ground. Repair or replace the wiring harness for a possible open circuit, then go to Step 21.
14	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION ). Is there any malfunction?	Yes	Go to the next step.
14		No	Go to Step 19.
15	INSPECT METERING OIL PUMP Inspect the metering oil pump. (See METERING OIL PUMP INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Overhaul or replace the engine, then go to Step 21.
15		No	Go to the next step.
16	INSPECT ENGINE OIL CONDITION Inspect the engine oil condition. Is the engine oil condition normal?	Yes	Go to the next step.
16		No	Replace the engine oil. Overhaul or replace the engine, then go to Step 21.
17	INSPECT OIL PRESSURE Inspect the oil pressure. (See OIL PRESSURE INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Overhaul or replace the engine, then go to Step 21.
17		No	Go to the next step.
18	INSPECT OIL PASSAGE Inspect the oil pipe between metering oil pump and metering oil nozzle. Is there any malfunction?	Yes	Inspect for leakage and/or clogged in oil passage at the engine. Repair or replace the malfunctioning part according to the inspection results. Overhaul or replace the engine, then go to Step 21.
18		No	Overhaul or replace the engine, then go to Step 21.
19	INSPECT FUEL INJECTOR Inspect the fuel injector. (See FUEL INJECTOR INSPECTION ). Is there any malfunction?	Yes	Replace the fuel injector, then go to Step 21. (See FUEL INJECTOR REMOVAL/INSTALLATION ).
19		No	Go to the next step.
20	INSPECT ENGINE COOLANT PASSAGE FOR ENGINE COOLANT LEAKAGE Perform the "ENGINE COOLANT LEAKAGE INSPECTION". (See ENGINE COOLANT LEAKAGE INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
20		No	Go to the next step.
21	VERIFY TROUBLESHOOTING OF DTC P2270 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE ). Perform the DRIVE MODE 3 (A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode). (See OBD-II DRIVE MODE ). Is the PENDING CODE same as DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
21		No	Go to the next step.
22	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE ". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
22		No	DTC troubleshooting completed.