Acura RL. Manual - part 72

Fig. 237: Charging System (High Voltage) - Circuit Diagram 

General Description 

The alternator is driven by the engine and generates electricity to supply the necessary power to the 
electrical system and to charge the battery. The alternator voltage target values of 14.5 V and 12.5 V are 
achieved by switching the alternator control mode (controlled by the powertrain control module (PCM)). 
The alternator output signal is sent to the PCM, and it varies according to the battery's state of charge, the 
electrical load, and engine rpm. 

When the IGP (power source) terminal voltage is a set value or less and this condition continues for a set 
time, the PCM detects a malfunction and a DTC is stored.

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

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Monitor Execution, Sequence, Duration, DTC Type, OBD Status

MONITOR DESCRIPTION CHART 

Enable Conditions 

ENABLE CONDITIONS 

Malfunction Threshold 

The IGP terminal voltage is 16.0 V or more for at least 60 seconds. 

Diagnosis Details 

Conditions for illuminating the indicator 

When a malfunction is detected, the DTC and the freeze frame data are stored in the PCM memory. The 
MIL does not come on. 

Conditions for clearing the DTC 

The DTC and the freeze frame data can be cleared by using the scan tool Clear command or by 
disconnecting the battery. 

DTC P1683 (40): ADVANCED DIAGNOSTICS 

DTC P1683: THROTTLE VALVE DEFAULT POSITION SPRING PERFORMANCE PROBLEM 

Fig. 238: Throttle Valve Default Position Spring Performance Graph

Execution

Continuous

Sequence

None

Duration

60 seconds or more

DTC Type

One drive cycle, MIL OFF

OBD Status

N/A

Condition

Minimum

Maximum

Engine speed

500 rpm

-

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

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General Description 

The electronic throttle control system (ETCS) controls the throttle valve opening. The system is composed 
of the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the throttle actuator control 
module, the throttle actuator control module relay, the accelerator pedal position (APP) sensor, and the 
powertrain control module (PCM). 

The throttle valve default position spring is attached to the throttle valve gear. It opens the throttle valve to 
improve starting performance in cold conditions, or to retain minimum running performance in case of an 
electronic throttle control system failure. 

If the throttle valve does not return to the default position when the throttle actuator control module moves 
the throttle actuator to the default position from the fully closed position, a malfunction is detected and the 
malfunction data is transmitted to the PCM. When the PCM receives the malfunction data from the throttle 
actuator control module, the PCM detects the malfunction of the throttle valve default position spring and a 
DTC is stored. 

Monitor Execution, Sequence, Duration, DTC Type, OBD Status 

MONITOR DESCRIPTION CHART 

Enable Conditions 

ENABLE CONDITIONS 

Malfunction Threshold 

The throttle valve is at a position greater than +5° from the fully closed position, or at a position lower than 
+3° from the fully closed position, for at least 2.5 seconds. 

Driving Pattern 

1. 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. Turn the ignition switch OFF.  

3. Turn the ignition switch ON.  

Diagnosis Details 

Execution

Once per driving cycle

Sequence

None

Duration

2.5 seconds or more

DTC Type

One drive cycle, MIL ON

OBD Status

N/A

Condition

Minimum

Maximum

Engine coolant temperature

158°F (69.5°C)

-

Battery voltage

6.0 V

-

Ignition switch

OFF

No active DTCs

P0117, P0118, P2101, P2108, P2118, P2135, P2176, U0107

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

Friday, June 05, 2009 2:32:06 PM

Page 287  © 2005 Mitchell Repair Information Company, LLC. 

Conditions for illuminating the MIL 

When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the 
PCM memory. 

Conditions for clearing the MIL 

The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the 
diagnostic runs. 

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by 
disconnecting the battery. 

DTC P1684 (40): ADVANCED DIAGNOSTICS 

DTC P1684: THROTTLE VALVE RETURN SPRING PERFORMANCE PROBLEM 

Fig. 239: Throttle Valve Return Spring Performance Graph 

General Description 

The electronic throttle control system (ETCS) controls the throttle valve opening. The system is composed 
of the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the throttle actuator control 
module, the throttle actuator control module relay, the accelerator pedal position (APP) sensor, and the 
powertrain control module (PCM). 

The throttle valve return spring is attached to the throttle valve gear to return the throttle valve to the default 
position. 

If the throttle valve does not return to the default position when the throttle actuator control module moves 
the throttle actuator to the default position from the middle position, a malfunction is detected and the 
malfunction data is transmitted to the PCM. When the PCM receives the malfunction data from the throttle 
actuator control module, the PCM detects the malfunction of the throttle valve return spring and a DTC is 
stored. 

Monitor Execution, Sequence, Duration, DTC Type, OBD Status 

 

2007 Acura RL 

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

  

me 

 

Friday, June 05, 2009 2:32:06 PM

Page 288  © 2005 Mitchell Repair Information Company, LLC.