DTC P2097

DTC P2097	Target A/F feedback system too rich
DETECTION CONDITION	The PCM monitors the target A/F fuel trim when under the target A/F feedback control. If the fuel trim is more than the specification, the PCM determines that the target A/F feedback system is too rich. Diagnostic support note This is a continuous monitor (fuel system). 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	Leakage exhaust gas HO2S malfunction Erratic signal to PCM APP sensor signal malfunction ECT sensor signal malfunction MAF sensor signal malfunction TP sensor signal malfunction VSS signal malfunction Loose installation of A/F sensor Leakage exhaust gas A/F sensor malfunction Fuel pump speed control malfunction Fuel line pressure malfunction Fuel pump unit malfunction Pressure regulator (built-in fuel pump unit) malfunction Purge solenoid valve malfunction Insufficient compression Metering oil pump malfunction Engine oil condition malfunction Increased oil pressure Oil passage malfunction Engine malfunction PCM malfunction

Target A/F feedback system too rich

DETECTION CONDITION

The PCM monitors the target A/F fuel trim when under the target A/F feedback control. If the fuel trim is more than the specification, the PCM determines that the target A/F feedback system is too rich.

Diagnostic support note

This is a continuous monitor (fuel system).
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

Leakage exhaust gas
HO2S malfunction
Erratic signal to PCM
- APP sensor signal malfunction
- ECT sensor signal malfunction
- MAF sensor signal malfunction
- TP sensor signal malfunction
- VSS signal malfunction
Loose installation of A/F sensor
Leakage exhaust gas
A/F sensor malfunction
Fuel pump speed control malfunction
Fuel line pressure malfunction
- Fuel pump unit malfunction
- Pressure regulator (built-in fuel pump unit) malfunction
Purge solenoid valve malfunction
Insufficient compression
- Metering oil pump malfunction
- Engine oil condition malfunction
- Increased oil pressure
- Oil passage malfunction
- Engine malfunction
PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2) Is the DTC P2097 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 (fuel system 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. Is the DTC P0172 also present?	Yes	Go to the DTC P0172 inspection. (See DTC P0172 ).
4		No	If misfire DTC is present or drivability concern exists, go to Step 11. If misfire DTC is not present and drivability concern does not exist, go to the next step.
5	INSPECT HO2S Inspect the HO2S. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION ). Is there any malfunction?	Yes	Visually inspect for the gas leakage between TWC and HO2S. If there is no leakage, replace the HO2S, then go to Step 17. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION ).
5		No	Go to the next step.
6	VERIFY CURRENT INPUT SIGNAL STATUS Access the following PIDs using the M-MDS: (See ON-BOARD DIAGNOSTIC TEST ). APP ECT MAF TP REL VSS Are the PIDs normal? (See PCM INSPECTION ).	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
7	VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA (MODE 2) CONDITION CAUTION: While performing this step with vehicle driving, always operate the vehicle in a safe and lawful manner. When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD function and inspect later. Access the following PIDs using the M-MDS under the FREEZE FRAME DATA (Mode 2) condition: (See ON-BOARD DIAGNOSTIC TEST ). APP ECT MAF TP REL VSS Are the PIDs normal? (See PCM INSPECTION ).	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
8	INSPECT A/F SENSOR Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION . Is there any malfunction?	Yes	Inspect the following: Loose installation of A/F sensor Exhaust gas leakage between exhaust manifold and A/F sensor If there is no malfunction detected, replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION If there is a malfunction detected, repair or replace the malfunctioning part according to the inspection results. Go to Step 17.
8		No	Go to the next step.
9	INSPECT FUEL PUMP SPEED CONTROL OPERATION Perform the Fuel Pump Speed Control Operation Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 17.
9		No	Go to the next step.
10	INSPECT FUEL LINE PRESSURE Perform the "FUEL LINE PRESSURE INSPECTION". (See FUEL LINE PRESSURE INSPECTION ). Is there any malfunction?	Yes	If the fuel line pressure is too low, go to the next step. If the fuel line pressure is too high, replace the fuel pump unit, then go to Step 17. (See FUEL PUMP UNIT REMOVAL/INSTALLATION ).
10		No	Go to Step 13.
11	INSPECT LONG TERM FUEL TRIM Access the LONGFT1 PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST ). Compare the LONGFT1 PID with recorded FREEZE FRAME DATA (Mode 12) at Step 2. Is the LONGFT1 PID above FREEZE FRAME DATA (Mode 12)?	Yes	Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION ). If there is any malfunction, replace the purge solenoid valve, then go to Step 17.
11		No	Go to the next step.
12	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION ). Is there any malfunction?	Yes	Go to the next step.
12		No	Go to Step 17.
13	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 17.
13		No	Go to the next step.
14	INSPECT ENGINE OIL CONDITION Inspect the engine oil condition. Is the engine oil condition normal?	Yes	Go to the next step.
14		No	Replace the engine oil. Overhaul or replace the engine, then go to Step 17.
15	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 17.
15		No	Go to the next step.
16	INSPECT OIL PASSAGE Inspect the oil pipe between metering oil pump and metering oil nozzle. Is there any malfunction?	Yes	Inspect for leakage or clogging in the engine oil passage. Repair or replace the malfunctioning part according to the inspection results. Overhaul or replace the engine, then go to the next step.
16		No	Overhaul or replace the engine, then go to the next step.
17	VERIFY TROUBLESHOOTING OF DTC P2097 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE ). Maintain the engine speed at 2, 500-3, 500 rpm for 15 s or more, then increase it to 4, 500-5, 000 rpm and maintain it for 15 s or more . Idle the engine until the cooling fan stops, then maintain the engine idling for 60 s or more . Perform the KOER self test. (See KOEO/KOER SELF TEST ). Is the PENDING CODE same as DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
17		No	Go to the next step.
18	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 ).
18		No	DTC troubleshooting completed.