Engine Controls - MIL ON/DTCs P0037/P0038/P0136
T-SB-0343-08November 5, 2008
M.I.L. "ON" DTC P0037, P0038, or P0136
Service Category
Engine/Hybrid System
Section
Engine Control
Market
USA
Applicability
TSB SUPERSESSION NOTICE
The information contained in this TSB supersedes TSB No. EG041-04.
- The Introduction has been modified.
- The Toyota Diagnostic Tester has been replaced with TIS Techstream in the Required Tools & Equipment section.
- The table in step 2 and the text in step 3 have been updated in the Repair Procedure.
TSB No. EG041-04 is Obsolete and any printed versions should be discarded. Be sure to review the entire content of this service bulletin before proceeding.
Introduction
Some 2004 model year Sienna vehicles equipped with AWD may exhibit a M.I.L. "ON" condition with one or more of the following Diagnostic Trouble Codes (DTCs):
- P0037 - Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2)
- P0038 - Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2)
- P0136 - Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)
Use the following repair procedure to address customer concerns.
Production Change Information
This TSB applies to vehicles produced BEFORE the Production Change Effective VIN shown above.
Warranty Information
APPLICABLE WARRANTY
- This repair is covered under the Toyota Federal Emission 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 Emission Warranty, which is 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.
Parts Information
Required Tools & Equipment
NOTE:
Additional TIS Techstream units may be ordered by calling Approved Dealer Equipment (ADE).
Repair Procedure
1. Disconnect Bank 1 Sensor 2 heated oxygen sensor connector H14.
2. Using a Digital Volt Ohm Meter (DVOM), measure the resistance between the terminals of the heated oxygen sensor connector.
3. If an open circuit is observed in the wiring harness for the oxygen sensor between terminals 1 - 2, replace the sensor.
NOTE:
Make sure to check for intermittent open circuits in the oxygen sensor wiring harness by moving the oxygen sensor wiring harness while checking the resistance values.
4. If NO problem with the oxygen sensor wiring harness is detected, follow Repair Manual diagnostics for the applicable DTC to determine the root cause of the DTC.
Refer to the Technical Information System (TIS), 2004 model year Sienna Repair Manual, for the applicable DTC (P0037, P0038, or P0136):
- Engine/Hybrid System - Engine Control - "SFI System: P0037, P0038, P0057, P0058 Oxygen Sensor Heater Control Circuit High"
- Engine/Hybrid System - Engine Control - "SFI System: P0136, P0156 Oxygen Sensor Circuit Malfunction"