Acura RL. Manual - part 28

Fig. 81: Evaporative Emission System Malfunction Detection

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 2:

The powertrain control module (PCM) monitors the fuel tank pressure (FTP) sensor output. If the FTP
sensor output does not indicate the specified vacuum when leak checking when the fuel vapor density is
high, the PCM detects a large leak (fuel fill cap loose/off) and a DTC is stored. [The malfunction detection
is performed during EVAP system leak detection (P0442, P0455, P0456).]

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Execution

Once per driving cycle

Sequence

None

Duration

45 seconds or less

DTC Type

Three drive cycles, MIL ON

OBD Status

N/A

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

* : Initial engine coolant temperature minus initial intake air temperature

** : Initial intake air temperature minus current intake air temperature

Malfunction Threshold



The output from the fuel tank pressure sensor is -0.1 kPa (-0.03 in.Hg, -1 mmHg) or more for at least
45 seconds.



Fuel vapor density during leak-checking is at least 0.1 g (0.004 oz) for up to 45 seconds.

Confirmation Procedure with the HDS

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

Driving Pattern

1. After the vehicle has been left for an appropriate amount of time as specified, with the engine coolant

temperature and intake air temperature within the specified range, start the engine.

2. Warm up the engine at idle until the radiator fan comes on.

3. Drive the vehicle at a speed between 45 - 75 mph (72 - 120 km/h) for at least 20 minutes.

4. After stopping the engine, turn the ignition switch off, and leave the vehicle for 32 minutes or more

(EONV executes).



Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Condition

Minimum

Maximum

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

Initial intake air temperature

40°F (5°C)

Engine coolant temperature

156°F (69°C)

212 °F (100 °C)

Engine coolant temperature
before EVAP purge control starts

140°F (60°C)

Vehicle speed

7 mph (10 km/h)

Battery voltage

10.5 V

Fuel trim

0.73

1.47

Fuel feedback

Closed loop at stoichiometric

No active DTCs

P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118,
P0125, P0134, P0135, P0154, P0155, P0335, P0339, P0443,
P0451, P0452, P0453, P0496, P0498, P0499, P1109, P1116,
P1128, P1129, P1172, P1174, P1454, P2195, P2197, P2227,
P2228, P2229, P2237, P2238, P2240, P2241, P2243, P2245,
P2247, P2249, P2251, P2252, P2254, P2255, P2422, P2627,
P2628, P2630, P2631

Others

Other than when there is excessive vapor generation (fuel level is
not full)
Avoid abrupt acceleration, deceleration, and turns
Test-drive on a flat road to avoid misdetection
No refueling is required

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Diagnosis Details

Conditions for illuminating the fuel fill cap caution

When a malfunction is detected during the first drive cycle with the ECT 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 at engine start-up within the specified temperature, the
caution is indicated. If the malfunction recurs during the next (third) drive cycle with the ECT at engine
start-up within the specified temperature range, the MIL comes on and the DTC and the freeze frame data
are stored. The caution is cleared when the MIL comes on.

Conditions for clearing the fuel fill cap caution

The caution will be cleared if the malfunction does not recur during the EVAP system leakage diagnostic.
The caution can be cleared by using the scan tool Clear command or by disconnecting the battery.

DTC P0461 (121): ADVANCED DIAGNOSTICS

DTC P0461: FUEL LEVEL SENSOR (FUEL GAUGE SENDING UNIT) CIRCUIT
RANGE/PERFORMANCE PROBLEM

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Fig. 82: Fuel Level Sensor Normal And Malfunction Graph

General Description

The fuel level sensor is incorporated with the fuel pump and installed in the fuel tank. Using a built-in
potentiometer and float, it converts the movement of the float into electrical signals that correspond to the
fuel level, and it indicates the amount of fuel in the fuel tank. If the powertrain control module (PCM)
receives no change in the fuel level sensor output after driving for a specified number of miles, it detects a
malfunction and stores a DTC.

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

MONITOR DESCRIPTION CHART

Execution

Once per driving cycle

Sequence

None

Duration

DTC Type

One drive cycle, MIL OFF

OBD Status

N/A

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

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