Acura RL. Manual - part 30

Fig. 85: Radiator Fan Control System - Circuit Diagram

General Description

The radiator fan control (RFC) system improves the control of the radiator fan motor and the condenser fan
motor and decreases noise and vibration. The powertrain control module (PCM) detects a malfunction when
the RFC terminal voltage remains at 0 V. However, the RFC power is shut off temporarily when a
malfunction is detected to differentiate it from the RFC protection function (*1). (Hereinafter, referred to as
'power reset') When the RFC terminal voltage remains at 0 V even when the power reset is repeated for set
time, the PCM detects a malfunction of the RFC and a DTC is stored.

*1 RFC protection function: When excessively high current due to a locked fan motor, etc. is detected or at
abnormally high temperatures, fan motor operation is limited to protect the RFC unit and keep the RFC
terminal voltage at 0 V. When the problem is cleared by turning off the power once and turning it on again,
the RFC protection function is canceled.

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

MONITOR DESCRIPTION CHART

Execution

Continuous

Sequence

None

Duration

105 seconds or more

DTC Type

One drive cycle, MIL OFF

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:04 PM

Enable Conditions

ENABLE CONDITIONS

Malfunction Threshold

The RFC terminal voltage is low for at least 20 seconds, and the same condition continues even when the
power reset is repeated 5 times. (Power is supplied for about 5 seconds after the power reset.)

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 P0496 (92): ADVANCED DIAGNOSTICS

DTC P0496: EVAPORATIVE EMISSION (EVAP) SYSTEM HIGH PURGE FLOW

Fig. 86: Evaporative Emission System High Purge Flow

OBD Status

N/A

Condition

Minimum

Maximum

Battery voltage

10.5 V

Ignition switch

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:04 PM

General Description

The powertrain control module (PCM) adjusts the amount of fuel vapor sent to the engine by controlling the
evaporative emission (EVAP) canister purge valve. If the EVAP canister purge valve is stuck open, engine
vacuum flows into the purge line before purge control starts when starting the engine. The PCM monitors
the fuel tank pressure (FTP) sensor output when purge control starts. If the FTP sensor output indicates
negative pressure, the PCM detects a malfunction in the EVAP canister purge valve, and a DTC is stored.

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Malfunction Threshold

The output from the fuel tank pressure sensor is -2 kPa (-0.6 in.Hg, -15 mmHg) or less for at least 10
seconds.

Confirmation Procedure with the HDS

Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

Execution

Once per driving cycle

Sequence

None

Duration

10 seconds or more

DTC Type

Two drive cycles, MIL ON

OBD Status

N/A

Condition

Minimum

Maximum

Elapsed time before starting the
engine

10 seconds

Initial condition A

(1)

18°F (10°C)

Initial condition B

(2)

18°F (10°C)

Initial engine coolant temperature 40°F (5°C)

95°F (35°C)

Initial intake air temperature

40°F (5°C)

95°F (35°C)

Engine coolant temperature
before EVAP purge control starts

140°F (60°C)

MAP value

81 kPa (24.0 in.Hg, 610 mmHg)

Battery voltage

10.5 V

Fuel trim

0.73

1.47

Fuel feedback

Closed loop

No active DTCs

P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118,
P0125, P0443, P0451, P0452, P0453, P0498, P0499, P1109,
P1116, P1128, P1129, P1454, P2227, P2228, P2229

(1)

Initial engine coolant temperature minus initial intake air temperature

(2)

Initial intake air temperature minus current intake air temperature

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:04 PM

Driving Pattern

Start the engine at an engine coolant temperature and intake air temperature as specified under Enable
Conditions, and let it idle until the radiator fan comes on.

Diagnosis Details

Conditions for illuminating the MIL

When a malfunction is detected during the first drive cycle with the ECT and IAT at engine start-up within
the specified temperature range, a Temporary DTC is stored in the PCM memory. If the malfunction recurs
during the next (second) drive cycle with the ECT and IAT at engine start-up within the specified
temperature range, the MIL comes on and the DTC and the freeze frame data are stored.

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

DTC P0497 (90): ADVANCED DIAGNOSTICS

DTC P0497: EVAPORATIVE EMISSION (EVAP) SYSTEM LOW PURGE FLOW

Fig. 87: Evaporative Emission System Low Purge Flow

General Description

There are two conditions when the evaporative emission (EVAP) system will not hold vacuum sufficiently,
and the pressure in the fuel tank doesn't become negative.

1. EVAP system low purge flow.

2. EVAP system leakage or the fuel fill cap is loose/off.

Here is a description of condition 1:

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:04 PM

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