Acura TSX / Honda Accord CL. Manual — part 598

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Engine speed at 2,000-3,000 RPM

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Drive about 10 minutes, then decelerate (with the throttle fully closed) for 5 seconds

5. Monitor the OBD STATUS for DTC P0139 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES: Go to step 6.

NO: If the screen indicates PASSED, intermittent failure, system is OK at this time. If the
screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates
Out of CONDITION, go to step 3 and recheck.

6. Turn the ignition switch OFF.

7. Replace the secondary HO2S (Sensor 2) (see SECONDARY HO2S REPLACEMENT ).

8. Turn the ignition switch ON (II).

9. Reset the ECM/PCM with the HDS.

10. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).

11. Start the engine. Hold the engine speed at 3,000 RPM with no load (in Park or neutral) until the radiator

fan comes on, then let it idle.

12. Test-drive under the following conditions:

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Engine coolant temperature more than 158°F (70°C)

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A/T in D position (M/T in 4th gear)

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Engine speed at 2,000-3,000 RPM

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Drive about 10 minutes, then decelerate (with the throttle fully closed) for 5 seconds.

13. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES: If DTC P0139 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 troubleshooting.

NO: Go to step 14.

14. Monitor the OBD STATUS for DTC P0139 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
EXECUTING, keep driving until a result comes on. If the screen indicates Out of
CONDITION, go to step 11 and recheck.

DTC P0141: SECONDARY HO2S (SENSOR 2) HEATER CIRCUIT MALFUNCTION

1. Turn the ignition switch ON (II).

2. Clear the DTC with the HDS.

3. Start the engine.

4. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

Is DTC P0141 indicated?

YES: Go to step 5.

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.

5. Check the No. 18 ACG (15A) 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. 4 ACG
(10A) fuse, then go to step 24 .

6. Turn the ignition switch OFF.

7. Disconnect the secondary HO2S (Sensor 2) 4P connector (see SECONDARY HO2S

REPLACEMENT ).

8. At the secondary HO2S (Sensor 2), measure resistance between secondary HO2S (Sensor 2) 4P connector

terminals No. 3 and No. 4.

Is there 5.0-6.4 ohm at room temperature?

YES: Go to step 9.

NO: Go to step 23 .

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

Fig. 38: Measuring Resistance Between Secondary HO2S (Sensor 2) 4P Connector Terminals
No. 3 & No. 4

9. At the secondary HO2S (Sensor 2), 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.

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX

Fig. 39: Checking For Continuity Between Body Ground & Secondary HO2S (Sensor 2) 4P
Connector Terminals No. 3 & No. 4

10. Turn the ignition switch ON (II).

11. On the harness side, measure voltage between secondary HO2S 4P connector terminals No. 3 and No. 4.

Is there battery voltage?

YES: Go to step 12.

NO: Go to step 16 .

2004 Acura TSX

2004 ENGINE PERFORMANCE PGM-FI System - TSX