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DTC P0141: 1/2 O2S Heater Failure

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION  . For wiring diagram, see WIRING DIAGRAMS article.
NOTE: 1/2 O2 sensor is referred to as downstream oxygen sensor in this test. Downstream oxygen sensor heater operation is monitored after ignition is turned off and engine cools down. DTC may be stored in Powertrain Control Module (PCM) if no downstream oxygen sensor signal is received when PCM powers up oxygen sensor heater. Possible causes are: defective downstream oxygen sensor or heater, defective Auto Shutdown (ASD) relay circuit, or defective connectors or wiring.
  1. Using scan tool, check for DTCs. If GLOBAL GOOD TRIP counter is displayed and equal to zero, go to next step. If GLOBAL GOOD TRIP counter is not displayed and equal to zero, go to step  3 .
  2. Turn ignition on with engine off. Wait 3 minutes and then use scan tool to read downstream oxygen sensor voltage. Monitor downstream sensor voltage until downstream oxygen sensor voltage stabilizes between .4 and .6 volt. Using scan tool in ACTUATOR mode, actuate oxygen sensor heater test while monitoring downstream oxygen sensor voltage for at least 2 minutes. Oxygen sensor heater test may also be referred to as O2 sensor heater test. If downstream oxygen sensor voltage does not remain .4-.6 volt, go to next step. If downstream oxygen sensor voltage remains at .4-.6 volt, go to step  4 .
  3. At this time, conditions for downstream oxygen sensor heater failure does not exist or is an intermittent problem. Using scan tool, read FREEZE FRAME data while attempting to duplicate the condition that caused DTC to be set by paying special attention to the conditions that downstream oxygen sensor heater is monitored. Downstream oxygen sensor heater operation is monitored after ignition is turned off and engine cools down. Recheck for DTC P0141: 1/2 O2S HEATER FAILURE. If DTC P0141: 1/2 O2S HEATER FAILURE exists, go to next step. If DTC P0141: 1/2 O2S HEATER FAILURE does not exist, oxygen sensor heater failure no longer exists. Perform TEST VER-5A3  .
  4. Disconnect downstream oxygen sensor connector. On 2.4L, downstream oxygen sensor is mounted near rear of catalytic converter. On 3.0L, 3.3L and 3.8L, downstream oxygen sensor is mounted on exhaust pipe, behind catalytic converter. On all models, inspect downstream oxygen sensor connector for corroded, pushed out, miswired or damaged terminals. If terminals are not corroded, pushed out, miswired or damaged, go to next step. If terminals are corroded, pushed out, miswired or damaged, repair connector as necessary. Perform TEST VER-5A3  .
  5. Turn ignition on with engine off. Ensure downstream oxygen sensor connector is still disconnected. Using scan tool in ACTUATOR mode, actuate oxygen sensor heater test.
  6. Using voltmeter, check voltage at terminal No. 2 (Dark Green/Orange wire) on wiring harness side of downstream oxygen sensor connector while still performing oxygen sensor heater test. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open on Dark Green/Orange wire between Auto Shutdown (ASD) relay and downstream oxygen sensor. ASD relay is located in power distribution center at driver's side front corner of engine compartment, near battery. Perform TEST VER-5A3  .
  7. Stop oxygen sensor heater test. Using ohmmeter, check resistance of downstream oxygen sensor heater between terminals No. 1 and 2 on oxygen sensor side of downstream oxygen sensor connector. Terminals No. 1 and 2 are the 2 top terminals on the connector, closest to release latch on the connector. If resistance is 4-7 ohms, go to next step. If resistance is not 4-7 ohms, replace downstream oxygen sensor. Perform TEST VER-5A3  .
  8. Using ohmmeter, check resistance between ground and terminal No. 1 (Black/Tan wire on 3.0L early build, or Black wire on 2.4L, 3.0L late build, 3.3L and 3.8L) on wiring harness side of downstream oxygen sensor connector. If resistance is less than 5 ohms, replace downstream oxygen sensor. Perform TEST VER-5A3  . If resistance is 5 ohms or more, repair open on Black/Tan wire on 3.0L early build, or Black wire on 2.4L, 3.0L late build, 3.3L and 3.8L, between downstream oxygen sensor and ground connection. Ground connection is located behind driver's side of instrument panel, just above kick panel. Perform TEST VER-5A3  .
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