Test TC-10A - Right O2S Stays At Center (DTC 21)

WARNING: This page is about a different car, the 1994 Eagle Vision, 1994 Dodge Intrepid, 1994 Chrysler New Yorker, 1994 Chrysler LHS, and 1994 Chrysler Concorde. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For circuit & connector terminal identification, see CONNECTOR IDENTIFICATION DIRECTORY TABLE . For wiring diagrams, see WIRING DIAGRAMS section. After each repair, perform TEST VER-2 .

NOTE: DRB displays left oxygen (O2) sensor as O2 and right oxygen (O2) sensor as O2R.

Start engine. Using DRB, read right O2 sensor voltage. If right O2 sensor voltage is locked on 0.5 volt, go to step 5). If right O2 sensor voltage is not locked on 0.5 volt, go to next step.
Wiggle right O2 sensor wiring while observing DRB display. If at any time right O2 sensor voltage locks on 0.5 volt, repair harness or connector that caused voltage to lock (open circuit). If right O2 sensor voltage does not lock on 0.5 volt, go to next step.
At this time, the condition required to set trouble code is not present. RIGHT O2S STAYS AT CENTER trouble code sets if right O2 sensor output voltage stays at 0.5 volt for 1.5 minutes with engine temperature more than 170°F (76.6°C) and engine running for 2 minutes. Possible causes are: right O2 sensor circuit open or right O2 sensor failure. Go to next step.
Inspect right O2 sensor wiring and connectors. Repair wiring and connectors as required. If wiring and connectors are okay, see INACTIVE TROUBLE CODE CONDITION in this article. Test is complete.
If right O2 sensor voltage is locked on 0.5 volt in step 1), disconnect right O2 sensor connector. Using DRB in ohmmeter mode, check resistance of O2 sensor connector terminal No. 1 (Black/Light Blue wire). If resistance is more than 5 ohms, repair open Black/Light Blue wire. If resistance is less than 5 ohms, go to next step.
Connect a jumper wire between right O2 sensor connector terminal No. 2 (Tan/White wire) and positive battery terminal. Using DRB, read right O2 sensor voltage. If voltage is more than one volt, replace right O2 sensor. If voltage is less than one volt, go to next step.
Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. PCM is located under air cleaner. Leave jumper wire connected. Using DRB in voltmeter mode, check voltage on PCM connector terminal No. 49 (Tan/White wire). If voltage is more than 10 volts, replace PCM. If voltage is less than 10 volts, repair open Tan/White wire.