Test TC-10A - Left O2S Stays Above Center (Rich) (DTC 52)

WARNING: This page is about a different car, the 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 diagrams, see WIRING DIAGRAMS section at the end of this article.

NOTE: Scan tool displays dual O2S as LT O2S and RT O2S.

Before performing test steps, check following components/systems for possible trouble code cause; catalyst, Exhaust Gas Recirculation (EGR) system, high fuel pressure, fuel injectors, Manifold Absolute Pressure (MAP) sensor, O2S failure, Coolant Temperature Sensor (CTS), evaporative emission system, mechanical engine failure, faulty wiring or faulty connectors. Go to next step.
Turn ignition off. Disconnect right O2S connector. Turn ignition on. Using scan tool, read LT O2S voltage. Wait for voltage reading to stabilize at 4.8-5.0 volts. Using scan tool, actuate fuel system while observing LT O2S voltage for 2 minutes. If voltage is not 4.8-5.0 volts, stop fuel system actuation. Reconnect right O2S connector. Go to step 6).
If voltage is 4.8-5.0 volts, disconnect left O2S connector. Ensure scan tool is still actuating fuel system. Using scan tool in voltmeter mode, check voltage on left O2S connector, Auto Shutdown (ASD) relay output circuit (Dark Green/Orange wire). If voltage is less than 10 volts, repair open Dark Green/Orange wire. Perform TEST VER-2.
If voltage is more than 10 volts, stop all actuator tests. Using an external ohmmeter, measure resistance of left O2S heater element circuit between O2S connector (sensor side) Black/White wire and Dark Green/Orange wire. If resistance is not 4-20 ohms, replace left O2S. Perform TEST VER-2.
If resistance is 4-20 ohms, using scan tool in ohmmeter mode, check resistance of left O2S connector (harness side), heater ground circuit (Black/White wire). If resistance is more than 5 ohms, repair open Black/White wire. Perform TEST VER-2. If resistance is less than 5 ohms, replace left O2S. Perform TEST VER-2.
Inspect all related wiring and connectors. Repair as necessary. Perform TEST VER-2. If no problems are found in wiring or connectors, perform tests listed in LEFT OXYGEN SENSOR RICH TESTS table, in sequence until problem is found.

LEFT OXYGEN SENSOR RICH TESTS

Application	Test
Fuel Pressure	NTC-3A
Coolant Temperature Sensor	NTC-4A
MAP Sensor	NTC-6A
Evaporative Emission System	NTC-13A
EGR System	NTC-14A
Oxygen Sensor Switching	NTC-7A
Mechanical Test	NTC-18A