Engine Controls - MIL ON/O2 Sensor DTC's Set
T-SB-0278-08September 5, 2008
M.I.L. "ON" DTC P2237, P2238, P2240, or P2241
Service Category
Engine/Hybrid System
Section
Engine Control
Market
USA
Applicability
Introduction
Some 2008 model year Avalon and 2008 - 2009 model year Camry (2GR-FE and 2AZ-FE) 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 Toyota Comprehensive Warranty. This warranty is in effect for 36 months or 36,000 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 TSB applies to vehicles produced BEFORE the Production Change Effective VINs shown.
Parts Information
Required Tools & Equipment
NOTE
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.
A. P2238 and/or P2237
B. P2241 and/or P2240
NOTE
If other A/F sensor DTCs are present along with any of the DTCs listed above, this TSB does NOT apply. Follow Repair Manual procedure to diagnose those DTCs.
3. Follow 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) applicable model and model year Repair Manual:
^ 2008 Avalon:
Engine/Hybrid System - Engine Control - "2GR-FE Engine Control: SFI System: P2237: Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)"
^ Camry (2GR-FE):
2008 / 2009 Camry, Engine/Hybrid System - Engine Control - "2GR-FE Engine Control System: SFI System: P2237: Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)"
^ Camry (2AZ-FE):
2008 / 2009 Camry, Engine/Hybrid System - Engine Control - "2AZ-FE Engine Control System: SFI System: P2237: Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)"
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.
NOTE
It is necessary to remove the intake manifold surge tank to access the engine wire harness on 2GR-FE vehicles. The intake manifold should be removed on 2AZ-FE engines.
HINT
On 2GR-FE engines it is NOT necessary to drain engine coolant or disconnect the water by-pass hoses from the throttle body.
Refer to TIS applicable model and model year Repair Manual:
For intake air surge tank removal:
^ 2008 Avalon:
Engine/Hybrid System - Fuel System - "2GR-FE Fuel: Fuel Injector: Removal"
^ Camry (2GR-FE):
2008 / 2009 Camry Engine/Hybrid System - Fuel System - "2GR-FE Fuel: Fuel Injector: Removal"
For intake manifold removal (2AZ-FE Only):
^ Camry (2AZ-FE):
2008 / 2009 Camry Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine Assembly: Removal"
For intake air surge tank installation (2GR-FE only):
^ 2008 Avalon:
Engine/Hybrid System - Fuel System - "2GR-FE Fuel: Fuel Injector: Installation"
^ Camry (2GR-FE):
2008 / 2009 Camry Engine/Hybrid System - Fuel System - "2GR-FE Fuel: Fuel Injector: Installation"
For intake manifold installation (2AZ-FE Only):
^ Camry (2AZ-FE):
2008 / 2009 Camry, Engine/Hybrid System - Engine Mechanical - "2AZ-FE Engine Mechanical: Engine Assembly: Installation"
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.