Mazda DTC P2097 Diagnostic

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 less 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 first drive cycle. • FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Leakage exhaust gas • Rear HO2S malfunction • IAT sensor malfunction • ECT sensor malfunction • Front HO2S malfunction • Excessive fuel line pressure • Fuel pump unit malfunction • Purge solenoid valve malfunction • Insufficient engine compression • PCM malfunction

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 less 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 first drive cycle.

• FREEZE FRAME DATA is available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Leakage exhaust gas

• Rear HO2S malfunction

• IAT sensor malfunction

• ECT sensor malfunction

• Front HO2S malfunction

• Excessive fuel line pressure

• Fuel pump unit malfunction

• Purge solenoid valve malfunction

• Insufficient engine compression

• PCM malfunction

Diagnostic procedure


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service 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.
2		No	Go to the next step.
3	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 P2178 or P2188 also present?	Yes	Go to the applicable DTC troubleshooting.
3		No	Go to the next step.
4	IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P2097 on FREEZE FRAME DATA?	Yes	Go to the next step.
4		No	Go to the FREEZE FRAME DATA DTC inspection.
5	VERIFY CURRENT INPUT SIGNAL STATUS OF REAR HO2S • Connect the WDS or equivalent to the DLC-2. • Start the engine and warm it up completely. • Access the O2S12 PID. • Read the O2S12 PID under following accelerator pedal condition (in PARK or NEUTRAL). – More than 0.45 V when suddenly depressing accelerator pedal (rich condition) – Less than 0.45 V just after releasing accelerator pedal (lean condition) • Is the PID normal?	Yes	Go to the next step.
5		No	Visually inspect for exhaust gas leakage between the TWC and rear HO2S. • If there is no leakage, replace the rear HO2S. (Then go to Step 11.
6	VERIFY CURRENT INPUT SIGNAL STATUS • Connect the WDS or equivalent to the DLC-2. • Verify the following PIDs – ECT – MAF – TP – VSS • Are the PIDs normal?	Yes	Go to the next step.
6		No	Inspect the malfunctioning part according to the inspection results. Then go to Step 11.
7	VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA CONDITION • Connect the WDS or equivalent to the DLC-2. • Verify the following PIDs under the FREEZE FRAME DATA condition. – ECT – MAF – TP – VSS • Are the PIDs normal?	Yes	Go to the next step.
7		No	Inspect the malfunctioning part according to the inspection results. Then go to Step 11.
8	VERIFY CURRENT INPUT SIGNAL STATUS OF FRONT HO2S • Connect the WDS or equivalent to the DLC-2. • Start the engine and warm it up completely. • Access the O2S11 PID. • Read the O2S11 PID under following accelerator pedal condition (in PARK or NEUTRAL). – More than 0.45 V when accelerator pedal is suddenly depressed (rich condition) – Less than 0.45 V just after release of accelerator pedal (lean condition) • Is the PID normal?	Yes	Go to the next step.
8		No	Visually inspect for exhaust gas leakage between the exhaust manifold and front HO2S. • If there is no leakage, replace front HO2S. Then go to Step 11.
9	INSPECT FUEL LINE PRESSURE • Perform the “FUEL LINE PRESSURE INSPECTION”. • Is there any malfunction?	Yes	Replace the fuel pump unit, then go to Step 11.
9		No	Go to the next step.
10	INSPECT LONG TERM FUEL TRIM • Connect the WDS or equivalent to the DLC-2. • Access the LONGFT1 PID. • Compare the LONGFT1 PID with recorded FREEZE FRAME DATA at Step 1. • Is the LONGFT1 PID above FREEZE FRAME DATA?	Yes	Inspect the purge solenoid valve. • If there is any malfunction, replace the purge solenoid valve. Then go to Step 17.
10		No	Go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P2097 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Perform the “PCM Adaptive Memory Produce Drive Mode”. • Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step.
11		No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. • Are any DTCs present?	Yes	Go to the applicable DTC inspection.
12		No	DTC troubleshooting completed.