Canada - Engine Control - MIL ON/DTC P0171/P0174
BulletinTSB2586
Issue Date
July 29, 2004
Title
M.I.L. "ON" DTC P0171 AND/OR P0174: ENGINE RUNNING LEAN
Component
ENGINE ELECTRICAL
Models
'04 RX 330
INTRODUCTION:
Some 2004 model year RX 330 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 RX 330 vehicles produced BEFORE the Production Change Effective VINs shown below.
PRODUCTION CHANGE INFORMATION:
WARRANTY INFORMATION:
PARTS INFORMATION:
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 RX 330 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
If NO - Check for other vacuum leaks or lean running conditions per TIS, 2004 model year RX 330 Repair Manual: Diagnostics: SFI System (3MZ-FE): P0171, P0172, P0174, P0175 System Too Lean (RX 330).
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 RX 330 Model Repair Manual: Diagnostics: SFI System (3M-FE): P0171, P0172, P0174, P0175 System Too Lean (RX 330).
5. Confirm lean running condition has been eliminated (short term fuel trims on All Data List less than 3% on both banks).
NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.