Acura RL. Manual - part 391

Fig. 6: Identifying VAT-40 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

4. Start the engine. Hold the engine speed at 3,000 RPM, with no load until the radiator fan comes on, 

then let it idle.  

5. Raise the engine speed to 2,000 RPM, and hold it there. 

Is the voltage over 15.1 V?  

YES -Check the alternator mounting bolt torque. If they are loose, retorque them. If the bolts are tight, 
replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ) or rear housing 
assembly (see ALTERNATOR OVERHAUL ). 

NO -Go to step 6. 

6. Release the accelerator pedal, and let the engine idle.  

7. Turn off all the accessories. Select the charging test on the tester.  

8. Remove the inductive pickup, and zero the ammeter.  

9. Place the inductive pickup over the B terminal wire of the alternator so the arrow points away from 

the alternator.  

10. Raise the engine speed to 2,000 RPM, and hold it there. 

Is the voltage less than 13.5 V?  

YES -Go to ALTERNATOR CONTROL CIRCUIT TROUBLESHOOTING . 

NO -Go to step 11. 

11. Apply a load with the VAT-40 until the battery voltage drops within 12-13.5 V. 

 

2007 Acura RL 

2005-08 ELECTRICAL Charging System - RL

  

me 

 

Friday, June 05, 2009 2:41:57 PM

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© 2005 Mitchell Repair Information Company, LLC. 

Is the amperage 87.5 A or more?  

YES -The charging system is OK. 

NO -Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ), or repair 
the alternator (see ALTERNATOR OVERHAUL ). 

ALTERNATOR CONTROL CIRCUIT TROUBLESHOOTING 

1. Connect the HDS to the data link connector (DLC), and check for DTCs. If a DTC is present, 

diagnose and repair the cause before continuing with this test.  

2. Disconnect the alternator 4P connector from the alternator.  

3. Start the engine, and turn on the headlights to high beam.  

4. Measure the voltage between alternator 4P connector terminal No. 2 and the positive terminal of the 

battery. 

Fig. 7: Measuring Voltage Between Alternator 4P Connector Terminal 2 And Battery Positive 
Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there 1 V or less?  

YES -Go to step 5. 

NO -Go to step 8. 

5. Jump the SCS line with the HDS, then turn the ignition switch OFF. 

6. Disconnect PCM connector A (31P).  

7. Check for continuity between PCM connector terminal A24 and body ground. 

NOTE:

If the charging system indicator is still on, replace the alternator (see 
ALTERNATOR REMOVAL AND INSTALLATION ).

NOTE:

This step must be done to protect the powertrain control module (PCM) 
from damage.

 

2007 Acura RL 

2005-08 ELECTRICAL Charging System - RL

  

me 

 

Friday, June 05, 2009 2:41:57 PM

Page 8 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 8: Checking Continuity Between PCM Connector Terminal A24 And Body Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES -Repair short in the wire between the alternator and the PCM. 

NO -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 ), then recheck. If the 
symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM 
REPLACEMENT ). 

8. Jump the SCS line with the HDS, then turn the ignition switch OFF. 

9. Disconnect PCM connector A (31P).  

10. Check for continuity between PCM connector terminal A24 and alternator 4P connector terminal No. 

2. 

Fig. 9: Checking Continuity Between PCM Connector Terminal A24 And Alternator 4P 
Connector Terminal 2 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES -Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ), or repair 
the alternator (see ALTERNATOR OVERHAUL ).

NOTE:

This step must be done to protect the PCM from damage.

 

2007 Acura RL 

2005-08 ELECTRICAL Charging System - RL

  

me 

 

Friday, June 05, 2009 2:41:57 PM

Page 9 

© 2005 Mitchell Repair Information Company, LLC. 

NO -Repair open in the wire between the alternator and the PCM.

DRIVE BELT INSPECTION 

1. Remove the right upper fender trim. 

Fig. 10: Identifying Right Upper Fender Trim 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

2. Inspect the belt for cracks or damage. If the belt is cracked or damaged, replace it.  

3. Check that the auto-tensioner indicator (A) is within the standard range (B) as shown. If it is out of the 

standard range, replace the drive belt (see DRIVE BELT REPLACEMENT ). 

Fig. 11: Identifying Auto-Tensioner Indicator Range 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

DRIVE BELT REPLACEMENT 

 

2007 Acura RL 

2005-08 ELECTRICAL Charging System - RL

  

me 

 

Friday, June 05, 2009 2:41:57 PM

Page 10 

© 2005 Mitchell Repair Information Company, LLC.