Subaru Crosstrek Service Manual: Dtc p0171 system too lean bank 1

Subaru Crosstrek Service Manual / Engine (diagnostics)(h4do) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc p0171 system too lean bank 1

ENGINE (DIAGNOSTICS)(H4DO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0171 SYSTEM TOO LEAN BANK 1

Refer to DTC P0172 for diagnostic procedure. Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0172 SYSTEM TOO RICH BANK 1">

1. OUTLINE OF DIAGNOSIS

Detect fuel system malfunction by the amount of main feedback control.

Diagnostic method

Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio measured by sensor.

2. EXECUTION CONDITION

Secondary parameters	Execution condition
Main feedback	In operation

3. GENERAL DRIVING CYCLE

Perform the diagnosis continuously at idling or at a constant speed after warming up the engine.

4. DIAGNOSTIC METHOD

Compare the diagnostic value with the threshold value, and if a condition meeting the malfunction criteria listed below continues for 10 s ? 3 time(s) or more, judge that there is a fault in the fuel system.

Judgment value

Malfunction Criteria	Threshold Value
Offset amount of main feedback compensation	≥ Value from Map

Map

Amount of air g/s (oz/s)	0 (0)	3.2 (0.11)	6.4 (0.23)	9.6 (0.34)	12.8 (0.45)	16 (0.56)	19.2 (0.68)
Threshold Value	1.33	1.33	1.33	1.33	1.33	1.33	1.33

Amount of air

g/s (oz/s)

0 (0)

3.2 (0.11)

6.4 (0.23)

9.6 (0.34)

12.8 (0.45)

16 (0.56)

19.2 (0.68)

Threshold Value

1.33

Time needed for diagnosis: 10 s ? 3 time(s)

Malfunction indicator light illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

Dtc p015b a/f / o2 sensor delayed response - lean to rich bank 1 sensor 1

ENGINE (DIAGNOSTICS)(H4DO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)DTC P015B A/F / O2 SENSOR DELAYED RESPONSE - LEAN TO RICH BANK 1 SENSOR 1NOTE:For the diagnostic procedure, refer ...

Dtc p0172 system too rich bank 1

ENGINE (DIAGNOSTICS)(H4DO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)DTC P0172 SYSTEM TOO RICH BANK 1DTC detecting condition:Detected when two consecutive driving cycles with fault o ...

Other materials:

Certification for immobilizer system
For models with "keyless access with push-button start system": Refer to "Certification for keyless access with push-button start system" 2-19. For models without "keyless access with push-button start system": U.S.-spec. models FCC ID: MOZRI-38BFH CAUTION FCC WARNING Chang ...

Removal
EXTERIOR/INTERIOR TRIM > Roof RailREMOVAL1. Remove the trim panel - roof. Roof Trim > REMOVAL">2. Remove the curtain airbag module. Curtain Airbag Module > REMOVAL">CAUTION:• Before handling the airbag system components, refer to “CAUTION” of “Gener ...

Removal
LIGHTING SYSTEM > Day Time Running ResistorREMOVAL1. Disconnect the ground cable from battery. NOTE">2. Lift up the vehicle.3. Remove the screw and clips, and turn over the front side of the mud guard - front.4. Remove the resistor assembly - daytime running light.CAUTION:The resistor ma ...