Electrical - MIL ON/Oxygen Sensor DTC's Set
L-SB-0071-08Rev1
August 19, 2008
M.I.L. "ON" P2237, P2238, P2240, or P2241
Service Category
Engine/Hybrid System
Section
Engine Control
Market
USA
Applicability
TSIB REVISION NOTICE
^ October 20, 2008 Rev1:
^ The Production Change Information section has been added.
Any previous printed versions of this service bulletin should be discarded.
Introduction
Some 2008 model year ES 350 vehicles may exhibit a M.I.L. "ON" condition with one of the following Diagnostic Trouble Codes (DTCs):
^ P2238 - Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)
^ P2237 - Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)
^ P2241 - Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)
^ P2240 - Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 2 Sensor 1)
An improved engine wiring harness has been developed to address this condition. Use the following repair procedure to diagnose and repair customer complaint vehicles.
Warranty Information
APPLICABLE WARRANTY
^ This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 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.
Production Change Information
This TSIB applies to vehicles produced BEFORE the Production Change Effective VIN shown below.
Parts Information
Required Tools & Equipment
Additional TIS Techstream units may be ordered by calling Approved Dealer Equipment (ADE).
Repair Procedure
1. Using TIS Techstream check for stored DTCs.
2. Verify one of the following DTCs are present:
^ P2238 and/or P2237
^ P2241 and/or P2240
If other A/F sensor DTCs are present along with any of the DTCs listed above, this TSIB does NOT apply. Follow Repair Manual procedure to diagnose those DTCs.
3. Follow the Repair Manual procedure to inspect the A/F sensor heater and Engine Room Junction Block (A/F Relay).
Refer to the Technical Information System (TIS) 2008 model year ES 350 Repair Manual
4. If the A/F sensor heater and Engine Room Junction Block (A/F Relay) are within Repair Manual specifications replace the engine wire harness.
It is necessary to remove the intake manifold surge tank to access the engine wire harness.
It is not necessary to drain engine coolant or disconnect the water by-pass hoses from the throttle body.
For intake air surge tank removal:
Refer to TIS 2008 model year ES 350 Repair Manual
For intake air surge tank installation:
Refer to TIS 2008 model year ES 350 Repair Manual
5. After replacing the engine harness clear DTCs and verify that no DTCs reset. Then warm vehicle to operating temperature and test drive to verify repair.