Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
For circuit description, see Circuit Description under DTCs P0120, P0122, P0123, P0220, P0222, P0223 & P2135.
Diagnostic Aids
Read freeze frame data using hand-held tester or OBD-II scan tool, as freeze frame data records engine conditions when a malfunction is detected. When troubleshooting, it is useful to determine whether vehicle was running or stopped, engine was warmed up or not, air-fuel ratio was lean or rich, etc. at time of malfunction.