Content .. 505 506 507 508 ..

Acura RL. Manual - part 507

THROTTLE BODY
CLEANING ).

Cold fast idle too low (MIL
works OK, no DTCs set)

1. Do the PCM idle learn

procedure (see PCM IDLE
LEARN PROCEDURE ).

2. Check the idle speed (see

IDLE SPEED
INSPECTION ).

3. Clean the throttle body (see

THROTTLE BODY
CLEANING ).

Incorrect valve adjustment

Cold fast idle too high (MIL
works OK, no DTCs set)

1. Do the PCM idle learn

procedure (see PCM IDLE
LEARN PROCEDURE ).

2. Check the idle speed (see

IDLE SPEED
INSPECTION ).

3. Do the throttle position

learning check (see
THROTTLE POSITION
LEARNING CHECK ).

Intake vacuum leaks

Idle speed fluctuates (MIL
works OK, no DTCs set)

1. Do the PCM idle learn

procedure (see PCM IDLE
LEARN PROCEDURE ).

2. Check the idle speed (see

IDLE SPEED
INSPECTION ).

3. Do the carbon accumulation

check (see CARBON
ACCUMULATION
CHECK ).

Intake vacuum leaks

After warming up, idle speed is
below specification without
load (MIL works OK, no
DTCs set)

1. Troubleshoot the alternator

FR signal circuit (see
ALTERNATOR FR
SIGNAL CIRCUIT
TROUBLESHOOTING ).

2. Do the carbon accumulation

check (see CARBON
ACCUMULATION
CHECK ).

Incorrect valve adjustment

After warming up, idle speed is
above specification without
load (MIL works OK, no
DTCs set)

1. Troubleshoot the alternator

FR signal circuit (see
ALTERNATOR FR
SIGNAL CIRCUIT
TROUBLESHOOTING ).

2. Inspect the APP sensor (see

APP SENSOR SIGNAL

Intake vacuum leaks

2007 Acura RL

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

Friday, June 05, 2009 2:33:27 PM

Page 23

INSPECTION ).

After warming up, idle speed
drops when steering wheel is
turning (MIL works OK, no
DTCs set)

1. Do the idle learn procedure

(see PCM IDLE LEARN
PROCEDURE ).

2. Troubleshoot the PSP switch

signal circuit (see PSP
SWITCH SIGNAL
CIRCUIT
TROUBLESHOOTING ).

3. Do the carbon accumulation

check (see CARBON
ACCUMULATION
CHECK ).

Power steering system problems

Low power (MIL works OK,
no DTCs set)

Check the fuel pressure (see FUEL
PRESSURE TEST ).



Low compression



Incorrect camshaft timing



Incorrect engine oil level



Restricted exhaust



Fuel contamination

Engine stalls (MIL works OK,
no DTCs set)

1. Do the PCM idle learn

procedure (see PCM IDLE
LEARN PROCEDURE ).

2. Check the fuel pressure (see

FUEL PRESSURE TEST ).

3. Check the idle speed (see

IDLE SPEED
INSPECTION ).

4. Troubleshoot the brake pedal

position switch signal circuit
(see BRAKE PEDAL
POSITION SWITCH
SIGNAL CIRCUIT
TROUBLESHOOTING ).



Intake air leaks



Faulty harness and sensor
connections



Fuel contamination

Difficult to refuel (MIL works
OK, no DTCs set)

1. Check the fuel vent tube

between the EVAP canister
and the fuel tank.

2. Check the fuel tank vapor

recirculation tube between the
fuel pipe and the fuel tank.

3. Inspect the fuel filler neck for

restrictions.

4. Replace the fuel tank unit (see

FUEL PUMP/FUEL
GAUGE SENDING UNIT
REPLACEMENT ).

5. Replace the fuel tank (see

FUEL TANK

Malfunctioning gas station
filling nozzle.

2007 Acura RL

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

Friday, June 05, 2009 2:33:27 PM

Page 24

SYSTEM DESCRIPTION

ELECTRONIC CONTROL SYSTEM

The functions of the fuel and emission control systems are managed by the powertrain control module
(PCM).

Self-diagnosis

The PCM detects a failure of a signal from a sensor or from another control unit and stores a Temporary
DTC or a DTC. Depending on the failure, a DTC is stored in either the first or the second drive cycle. When
a DTC is stored, the PCM turns on the malfunction indicator lamp (MIL) by supplying ground to the MIL
circuit.



One Drive Cycle Detection Method

When an abnormality occurs in the signal from a sensor or from another control unit, the PCM stores
a DTC for the failure and turns on the MIL immediately.



Two Drive Cycle Detection Method

When an abnormality occurs in the signal from a sensor or from another control unit in first drive
cycle, the PCM stores a Temporary DTC for the failure. The MIL does not come on at this time. If the
failure continues in the second drive cycle, the PCM stores a DTC and turns on the MIL.

Fail-safe Function

When an abnormality occurs in the signal from a sensor or from another control unit, the PCM ignores that
signal and Substitutes a pre-programmed value that allows the engine to continue running. This causes a
DTC to be stored and the MIL to come on.

MIL Bulb Check and Readiness Code Condition

When the ignition switch is turned ON (II), the PCM supplies ground to the MIL circuit for about 15 to 20
seconds to check the bulb condition. If any readiness codes are not set to complete, the MIL flashes five

REPLACEMENT ).

Fuel overflows during
refueling (No DTCs set)

1. Replace the fuel tank unit (see

FUEL PUMP/FUEL
GAUGE SENDING UNIT
REPLACEMENT ).

2. Inspect the fuel filler neck for

restrictions.

3. Replace the fuel tank (see

FUEL TANK
REPLACEMENT ).

Malfunctioning gas station
filling nozzle.

HDS does not communicate
with the PCM or the vehicle

Troubleshoot the DLC circuit (see
DLC CIRCUIT
TROUBLESHOOTING ).

2007 Acura RL

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

Friday, June 05, 2009 2:33:27 PM

Page 25

times. If all readiness codes are set to complete, the MIL goes off.

Self Shut Down (SSD) Mode

After the ignition switch is turned OFF, the PCM stays on (about 30 minutes). If the PCM connector is
disconnected during this time, the PCM may be damaged. To cancel this mode, disconnect the negative
cable from the battery or jump the SCS line with the HDS after the ignition switch is turned OFF.

PCM Electrical Connections

Fig. 10: PCM Electrical Connections Circuit Diagram (1 Of 6)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2007 Acura RL

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

Friday, June 05, 2009 2:33:27 PM

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Content .. 505 506 507 508 ..