Acura RL. Manual - part 694

in step 3, go to step 1. 

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the 
original PCM (see PCM REPLACEMENT ). If any other Temporary DTCs or DTCs are indicated, 
go to the indicated DTCs troubleshooting 

DTC P2237: REAR A/F SENSOR (BANK 1, SENSOR 1) IP CIRCUIT HIGH VOLTAGE; DTC 
P2240: FRONT A/F SENSOR (BANK 2, SENSOR 1) IP CIRCUIT HIGH VOLTAGE 

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 without load (in Park or neutral) until the 

radiator fan comes on, then let it idle 2 minutes.  

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

Is DTC P2237 and/or P2240* indicated?  

YES - Go to step 5. 

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals 
at the A/F sensor (Sensor 1) and the PCM 

5. Turn the ignition switch OFF.  

6. Jump the SCS line with the HDS.  

7. Disconnect the A/F sensor (Sensor 1) 8P connector.  

8. Disconnect PCM connector B (24P).  

9. Connect A/F sensor (Sensor 1) 8P connector terminal No. 7 to body ground with a jumper wire. 

Fig. 95: Connecting A/F Sensor (Sensor 1) 8P Connector Terminal No. 7 To Body Ground With 
Jumper Wire 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

NOTE:



Before you troubleshoot, record all freeze data and any on-board 
snapshot, and review the general troubleshooting information (see 
GENERAL TROUBLESHOOTING INFORMATION ).  



Information marked with an asterisk (*) applies to the front bank (Bank 
2).  

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

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10. Check for continuity between PCM connector terminal B14 (B22)* and body ground. 

Fig. 96: Checking Continuity Between PCM Connector Terminal B14 (B22) And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Go to step 11. 

NO - Repair open in the wire between the PCM (B14 (B22) *) and the A/F sensor (Sensor 1), then go 
to step 15. 

11. Remove the jumper wire from the A/F sensor (Sensor 1) 8P connector, then reconnect PCM connector 

B (24P).  

12. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the 

radiator fan comes on, then let it idle 2 minutes.  

13. Measure voltage between PCM connector terminals B14 (B22)* and C12. 

Fig. 97: Measuring Voltage Between PCM Connector Terminals B14 (B22) And C12 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there about 0.2 V or less?  

YES - Go to step 21. 

NO - Go to step 14. 

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

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Friday, June 05, 2009 2:34:59 PM

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14. Replace the A/F sensor (Sensor 1) (see A/F SENSOR REPLACEMENT ).  

15. Reconnect all connectors.  

16. Turn the ignition switch ON (II).  

17. Reset the PCM with the HDS.  

18. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).  

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

Is DTC P2237 and/or P2240* indicated?  

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM, then 
go to step 1. 

NO - Go to step 20. 

20. Monitor the OBD STATUS for DTC P2237 and/or P2240* in the DTCs MENU with the HDS. 

Does the screen indicate PASSED?  

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 19, 
go to the indicated DTCs troubleshooting 

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor 
(Sensor 1) and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, keep idling 
until a result comes on. 

21. Turn the ignition switch OFF.  

22. Reconnect all connectors.  

23. Update the PCM if it does not have the latest software (see UPDATING THE PCM ), or substitute a 

known-good PCM (see SUBSTITUTING THE PCM ).  

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

Is DTC P2237 and/or P2240* indicated?  

YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the 
PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. 
If the PCM was substituted, go to step 1. 

NO - Go to step 25. 

25. Monitor the OBD STATUS for DTC P2237 and/or P2240* in the DTCs MENU with the HDS. 

Does the screen indicate PASSED?  

YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the 
original PCM (see PCM REPLACEMENT ). If any other Temporary DTCs or DTCs were indicated 
in step 24, go to the indicated DTCs troubleshooting 

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor 

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

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Friday, June 05, 2009 2:34:59 PM

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(Sensor 1) and the PCM. If the PCM was updated, substitute a known-good PCM (see 
SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step 1. If the screen 
indicates NOT COMPLETED, keep idling until a result comes on. 

DTC P2238: REAR A/F SENSOR (BANK 1, SENSOR DIP CIRCUIT LOW VOLTAGE; DTC 
P2241: FRONT A/F SENSOR (BANK 2, SENSOR DIP CIRCUIT LOW VOLTAGE 

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 without load (in Park or neutral) until the 

radiator fan comes on, then let it idle 2 minutes.  

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

Is DTC P2238 and/or P2241* indicated?  

YES - Go to step 5. 

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals 
at the A/F sensor (Sensor 1) and the PCM 

5. Turn the ignition switch OFF.  

6. Jump the SCS line with the HDS.  

7. Disconnect the A/F sensor (Sensor 1) 8P connector.  

8. Disconnect PCM connector B (24P).  

9. Check for continuity between PCM connector terminals B14 (B22)* and C12. 

Fig. 98: Checking Continuity Between PCM Connector Terminals B14 (B22) And C12 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

NOTE:



Before you troubleshoot, record ail freeze data and any on-board 
snapshot, and review the general troubleshooting information (see 
GENERAL TROUBLESHOOTING INFORMATION ).  



Information marked with an asterisk (*) applies to the front bank (Bank 
2).  

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE PGM-FI System - RL

  

me 

 

Friday, June 05, 2009 2:34:59 PM

Page 121  © 2005 Mitchell Repair Information Company, LLC.