Engine - MIL ON/DTC's P0171/P0174 Set
ENGINEEG029-04
Title:
M.I.L. "ON" DTC P0171 AND/OR P0174:
ENGINE RUNNING LEAN
Models:
'04 Camry, Sienna & Solara (3MZ-FE)
August 4, 2004
Introduction
Some 2004 model year Camry, Sienna and Solara (3MZ-FE) vehicles may exhibit a M.I.L. "ON" condition with one or both of the following Diagnostic Trouble Codes stored as a result of a vacuum leak in the Intake Air Control Valve.
^ P0171 (System Too Lean [Bank 1])
^ P0174 (System Too Lean [Bank 2])
Applicable Vehicles
^ 2004 model year Camry, Sienna and Solara vehicles (3MZ-FE engine only) produced BEFORE the Production Change Effective VINs shown below.
Production Change Information
Parts Information
Warranty Information
Applicable Warranty*:
This repair is covered under the Toyota Federal Emissions Warranty. This warranty is in effect for 36 months or 36,000 miles, whichever occurs first, from the vehicle's in-service date.
For California specification vehicles registered and operated in California, Maine, Massachusetts or Vermont, this repair is covered under the California Emissions Warranty, which is in effect for 36 months or 50,000 miles, whichever occurs first, from the vehicle's in-service date.
* Warranty application is limited to correction of a problem based upon a customer's specific complaint.
Required SSTs
Repair Procedure
1. Monitor the Bank 1 and Bank 2 Short Term Fuel Trim in the Data List.
2. Spray carburetor cleaner near the Intake Air Control Valve pivot shaft and monitor Short Term Fuel Trim as indicated in step 1.
3. Was the short term fuel trim changing to a rich reading, or negative fuel trim in step 2?
If Yes - Replace the Intake Air Control Valve. Refer to the Technical Information System (TIS), 2004 model year applicable model Repair Manual: Intake: Intake Air Control Valve Assy No. 2 (3MZ-FE): Replacement.
After the Intake Air Control Valve has been replaced, proceed to step 4.
If NO - Check for other vacuum leaks or lean running conditions per Technical Information System (TIS), 2004 model year applicable model Repair Manual: Diagnostics: SFI System (3MZ-FE): P0171, P0172, P0174, P0175 System Too Lean.
4. Is the short term fuel trim now in the negative percent? Is the long term fuel trim returning closer to 0%?
If Yes - Clear short and long term fuel trims by disconnecting the negative battery cable for 90 seconds. Reconnect the negative battery cable and test drive the vehicle.
After the test drive, proceed to step 5.
If NO - Continue diagnosis for lean running conditions per TIS, 2004 model year applicable model Repair Manual: Diagnostics: SFI System (3MZ-FE): P0171, P0172, P0174, P0175 System Too Lean.
5. Confirm lean running condition has been eliminated (short term and long term fuel trims on All Data List are less than +/- 3% on both banks).