Test TC-10A - Oxygen Sensor (O2S) Stays Above Center (Rich) (DTC 52)
WARNING: This page is about a different car, the 1995 Jeep Wrangler, 1995 Jeep Grand Cherokee, and 1995 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Perform TEST TC-1A
before proceeding with this test. For connector terminal identification, see CONNECTOR IDENTIFICATION
at beginning of article. For wiring diagrams, see WIRING DIAGRAMS
at the end of this article. Perform TEST VER-2A
after each repair.
- 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 O2S voltage. If O2S voltage is not always more than .5 volt, go to next step. If O2S voltage is always more than .5 volt, go to step 3).
- Condition required to set trouble code message is not present at this time. O2S STAYS ABOVE CENTER (RICH) trouble code message sets if O2S output voltage stays at more than .5 volt, but less than 1.2 volts, without changing for more than 8 minutes. Possible causes are: high fuel pressure, other engine sensor calibration failures, ignition system failure, O2S failure or mechanical engine problem.
- Using scan tool, stop all actuation tests. Turn ignition off. Inspect air cleaner filter and inlet ducts for restrictions. If restrictions are present, repair as necessary. If restrictions are not present, go to next step.
- Turn ignition off. Relieve fuel pressure. See FUEL PRESSURE RELEASE under SELF-DIAGNOSTIC SYSTEM. Install a fuel gauge to fuel rail test port. Turn ignition on. Using scan tool, actuate ASD fuel system test. Allow fuel pressure gauge to stabilize at normal fuel pressure. Go to next step.
- Using scan tool, stop ASD fuel system test. Monitor fuel pressure gauge for one minute. Ensure fuel pressure hose adapters and gauge are not leaking. If fuel pressure does not drop more than 10 psi (.7 kg/cm2 ), a condition causing engine to run rich is present. Return to step 2). If fuel pressure drops more than 10 psi (.7 kg/cm2 ), replace leaking fuel injector(s) and necessary.