Acura TSX / Honda Accord CL. Manual - part 515

For starter torque specifications, see TORQUE SPECIFICATIONS in ACURA - TSX article in 
SPECIFICATIONS. 

WIRING DIAGRAMS 

For wiring diagram on 2004 TSX models, see appropriate SYSTEM WIRING DIAGRAM article in 
ELECTRICAL. 

 

2004 Acura TSX 

2004 STARTING & CHARGING SYSTEMS Starter - TSX

  

 

2004 ENGINE PERFORMANCE

Catalytic Convertor System - TSX 

DTC TROUBLESHOOTING 

DTC P0420: CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD 

1. Turn the ignition switch ON (II).  

2. Clear the DTC with the HDS.  

3. 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.  

4. Test-drive under the following conditions. 

z

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

z

Transmission in 5th gear (A/T in D position)  

z

Vehicle speed between 50 MPH (80 km/h) and 55 MPH (88 km/h) with cruise control set  

z

Drive about 2 minutes, decelerate for at least 4 seconds with the throttle completely closed, then 
maintain 55 MPH (88 km/h) for 20 minutes with cruise control set  

5. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. 

Does the screen indicate EXECUTING? 

YES: Go to step 6.  

NO: Go to step 4 and recheck.  

6. Continue test driving until a result comes on.  

7. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. 

Does the screen indicate FAILED? 

YES: Go to step 8.  

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 4 and recheck.  

8. Turn the ignition switch OFF.  

9. Replace the three way catalytic converter (TWC) (see EXHAUST PIPE & MUFFLER 

REPLACEMENT ).  

10. Turn the ignition switch ON (II).  

11. Reset the ECM/PCM with the HDS.  

NOTE:

Poor quality fuel may cause this DTC. If some of the DTCs listed below are 
stored at the same time as DTC P0420, troubleshoot those DTCs first, then 
recheck for DTC P0420: 

z

P0137, P0138: Secondary HO2S (Sensor 2)  

z

P0141: Secondary HO2S (Sensor 2) Heater  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE Catalytic Convertor System - TSX

  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE Catalytic Convertor System - TSX

  

 

 

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

13. 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.  

14. Test-drive for about 10 minutes, varying the vehicle speed.  

15. Check the CATA MON TEMP in the DATA LIST with the HDS. 

Is the temperature OK? 

YES: Go to step 16.  

NO: Go to step 13 and recheck.  

16. Test-drive under the following conditions: 

z

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

z

Transmission in 5th gear (A/T in D position)  

z

Vehicle speed between 50 MPH (80 km/h) and 55 MPH (88 km/h) with cruise control set  

z

Drive about 2 minutes, decelerate for at least 4 seconds with the throttle completely closed, then 
maintain 55 MPH (88 km/h) for 20 minutes with cruise control set  

17. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. 

Does the screen indicate EXECUTING? 

YES: Go to step 18.  

NO: Go to step 16 and recheck.  

18. Continue test driving until a result comes on.  

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

Are any Temporary DTCs or DTCs indicated? 

YES: Go to the indicated DTC troubleshooting.  

NO: Go to step 20.  

20. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. 

Does the screen indicate PASSED? 

YES: Troubleshooting is complete.  

NO: If the screen indicates FAILED, check the fuel quality. If the screen indicates 
EXECUTING, keep driving until a result comes on. If the screen indicates Out of 
CONDITION, go to step 13 and recheck. 

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE Catalytic Convertor System - TSX

  

 

2004 ENGINE PERFORMANCE

Electronic Throttle Control System - TSX 

COMPONENT LOCATION INDEX 

Fig. 1: Locating Electronic Throttle Control System Components (1 Of 2)

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE Electronic Throttle Control System - TSX

  

 

2004 Acura TSX 

2004 ENGINE PERFORMANCE Electronic Throttle Control System - TSX