1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to
DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
2.
Install scan tool. Start engine. Operate vehicle within the Conditions for Running the DTC. See
CONDITIONS FOR RUNNING DTC . Record the LT FT Cruise/Accel and LT FT Idle/Decel
parameter values. Turn engine off. Turn ignition on, with engine off. Review the Freeze Frame/Failure
Records and record displayed data for this DTC. Does the scan tool indicate that the LT FT Cruise/Accel
parameter is more than 23 percent? If yes, go to step 4 . If no, go to next step.
3. Does the scan tool indicate that the LT FT Idle/Decel parameter is more than 8.1 percent? If yes, go to
next step. If no, go to DIAGNOSTIC AIDS .
4. Operate engine at idle. Observe the front HO2S parameters with a scan tool. Does the scan tool indicate
that the values are within 200-800 mV and fluctuating? If yes, go to next step. If no, go to step 6 .
5. Turn engine off. Visually and physically inspect vacuum hoses for splits, kinks, and proper connections.
Ensure that the vehicle has sufficient fuel. If fuel pressure is too low, this DTC may set. Did you find and
correct the condition? If yes, go to step 8 . If no, go to step 7 .
6. Turn engine off. Inspect the HO2S for proper installation. Verify that the electrical connectors and wires
are secured and are not contacting the exhaust system. Did you find and correct the condition? If yes, go
to step 8 . If no, diagnose fuel system. Refer to FUEL SYSTEM DIAGNOSIS under FUEL SYSTEMS
in BASIC DIAGNOSTIC PROCEDURES - 2.2L & 3.0L VUE article.
7. Operate the engine at idle. Inspect for missing, loose, or leaking exhaust components. Inspect for vacuum
leaks at the intake manifold and injector "O" rings, air induction system and air intake ducts for vacuum
leaks, or crankcase ventilation system for leaks. Check for a skewed MAF sensor. Did you find and
NOTE: If any DTCs are set other than DTC P0171 or P0174, diagnose affected DTC
(s) before continuing with test. Refer to DIAGNOSTIC TROUBLE CODE
DEFINITIONS .
correct the condition? If yes, go to next step. If no, diagnose for an engine mechanical problem.
8.
Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate vehicle within
the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also
operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did
the DTC fail this ignition? If yes, go to step 2 . If no, go to next step.
9. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes,
diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are
displayed, system is okay.
Diagnostic Aids
? A skewed MAF sensor may set this DTC. Refer to DTC P0101: MASS AIRFLOW SYSTEM
PERFORMANCE .
? System will go lean if an injector is not suppling enough fuel.
? A skewed ECT may set this DTC.
? System will go lean during high fuel demand.
? Review the Failure Records with a scan tool. If an intermittent condition is suspected, refer to
INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.
Author
Topic: Ошибка Р0171 (Read 1336 times)