DTC Troubleshooting: P0141 (65)

DTC P0141: Secondary HO2S (Sensor 2) Heater Circuit Malfunction NOTE: Information marked with an asterisk ( * ) applies to RHD model.

1. Turn the ignition switch ON (II).

1. Clear the DTC with the HDS.

1. Start the engine.

1. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0141 indicated?

YES | - | Go to Step 4 .
NO | - | Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM.■

1. Check the No. 18 ACG (15 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES | - | Go to Step 6 .
NO | - | Repair short in the wire between the secondary HO2S (Sensor 2) and the No. 18 ACG (15 A) fuse, then go to Step 26 .

1. Turn the ignition switch OFF.

1. Disconnect the secondary HO2S (Sensor 2) 4P connector.

1. At the secondary HO2S (Sensor 2) side, measure resistance between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.

Is there 5.0−6.4 Ω at room temperature?

YES | - | Go to Step 9 .
NO | - | Go to Step 23 .

1. At the secondary HO2S (Sensor 2) side, check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4 individually.

Is there continuity?

YES | - | Go to Step 23 .
NO | - | Go to Step 10 .

1. Turn the ignition switch ON (II).

1. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.

Is there battery voltage?

YES | - | Go to Step 12 .
NO | - | Go to Step 16 .

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

1. Disconnect ECM/PCM connector E (31P).

1. Check for continuity between ECM/PCM connector terminal E21 and body ground.

Is there continuity?

YES | - | Repair short in the wire between the ECM/PCM (E21) and the secondary HO2S (Sensor 2), then go to Step 26 .
NO | - | Go to Step 30 .

1. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and body ground.

Is there battery voltage?

YES | - | Go to Step 17 .
NO | - | Check the No. 18 ACG (15 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the secondary HO2S (Sensor 2) and the No. 18 ACG (15 A) fuse, then go to Step 26 .

1. Turn the ignition switch OFF.

1. Jump the SCS line with the HDS.

1. Reconnect the secondary HO2S (Sensor 2) 4P connector.

1. Disconnect ECM/PCM connector E (31P).

1. Turn the ignition switch ON (II).

1. Measure voltage between ECM/PCM connector terminal A5 and E21.

Is there 0.1 V or less?

YES | - | Repair open in the wire between the ECM/PCM (E21) and the secondary HO2S (Sensor 2), then go to Step 25 .
NO | - | Go to Step 30 .

1. Turn the ignition switch OFF.

1. Replace the secondary HO2S (Sensor 2).

1. Reconnect all connectors.

1. Turn the ignition switch ON (II).

1. Reset the ECM/PCM with the HDS.

1. Do the ECM/PCM idle learn procedure.

1. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC P0141 is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | Go to Step 30 .

1. Monitor the OBD STATUS for DTC P0141 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES | - | Troubleshooting is complete.■
NO | - | If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 28 and recheck.

1. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

1. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES | - | If DTC P0141 is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to Step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO | - | If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. ■