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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 41 (Engine Controls - Tests W/Codes - 5.9L Gasoline) >> Self-Diagnostic Tests >> Test TC-9A - Right O2S Stays At Center

Test TC-9A - Right O2S Stays At Center

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION  . For wiring diagram, see WIRING DIAGRAMS  section at the end of this article.
NOTE: BR body (heavy duty engine) is equipped with dual O2S. Scan tool displays dual O2S as LT O2S and RT O2S.
  1. Start engine. Allow engine to run until normal operating temperature is reached. Using scan tool, set engine speed to 1500 RPM. Using scan tool, read RT O2S voltage. If RT O2S voltage is switching between less than 0.4 volt to more than 0.6 volt, go to next step. If RT O2S is not switching between less than 0.4 volt to more than 0.6 volt, go to step 5).
  2. Wiggle RT O2S connector and wiring harness while watching scan tool display. If RT O2S voltage goes to more than 4.8 volts at any time, repair wiring and connectors as necessary. Perform TEST VER-2. If voltage does not go to more than 4.8 volts at any time, condition required to set trouble code is not present at this time. Go to next step.
  3. RIGHT O2S STAYS AT CENTER trouble code sets if RT O2S signal circuit voltage is more than 4.8 volts after engine is running for more than 2 minutes with engine temperature more than 176°F (80°C). Possible causes are: RT O2S failure, open RT O2S signal circuit (Black/Dark Green wire) or open RT O2S ground circuit (Black/Light Blue wire). Go to next step.
  4. Inspect all related wiring and connectors. Repair wiring or connectors as necessary. Perform TEST VER-2. If no problems are found with wiring and connectors, see INACTIVE TROUBLE CODE CONDITION  . Test is complete. Perform TEST VER-2.
  5. Turn ignition on with engine off. Disconnect RT O2S connector. Using scan tool in voltmeter mode, check voltage of RT O2S signal circuit (Black/Dark Green wire) on RT O2S harness connector. If voltage is less than 10 volts, go to next step. If voltage is more than 10 volts, repair short to voltage on Black/Dark Green wire. Perform TEST VER-2.
  6. Put scan tool in ohmmeter mode. Using scan tool, check resistance on RT O2S ground circuit (Black/Light Blue wire) on RT O2S harness connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Black/Light Blue wire. Perform TEST VER-2.
  7. Connect a jumper wire between RT O2S signal circuit (Black/Dark Green wire) and ground. Using scan tool, read RT O2S voltage. If voltage is more than 0.2 volt, go to next step. If voltage is less than 0.2 volt, replace RT O2S. Perform TEST VER-2.
  8. Disconnect jumper wire. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using an external ohmmeter, check resistance of RT O2S signal circuit (Black/Dark Green wire) between RT O2S connector harness side and PCM connector terminal No. 41. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-2. If resistance is more than 5 ohms, repair open Black/Dark Green wire. Perform TEST VER-2.
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