Acura RL. Manual - part 18

1. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the

radiator fan comes on.

2. Drive the vehicle at a speed between 15 - 75 mph (24 - 120 km/h) for at least 3 minutes.

3. Stop the vehicle, and let the engine idle for at least 3 minutes.



When freeze frame data is stored, drive the vehicle under those conditions instead of Driving Patterns
2 or 3.



When you have difficulty duplicating the DTC because of road conditions and traffic situations,
repeat the driving pattern several times.



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

Diagnosis Details

Conditions for illuminating the MIL

Misfire Type 1: Under high rpm or high load conditions: The MIL blinks once per second if a type 1 misfire
(catalyst damaging) occurs, and a Temporary DTC is stored. If the type 1 misfire ceases, the MIL goes off.
If a type 1 misfire occurs during the next (second) drive cycle, the MIL blinks at the first misfire occurrence,
and the DTC and the freeze frame data are stored. The MIL remains on steady if the type 1 misfire ceases.

Under normal driving conditions: The MIL blinks once per second if a type 1 misfire occurs a third time,
and a Temporary DTC is stored. If a type 1 misfire occurs during the next (second) drive cycle, the MIL
blinks during the third type 1 misfire occurrence, and the DTC and the freeze frame data are stored. If the
type 1 misfire ceases, the MIL remains on steady.

Misfire Type 2: When a type 2 misfire (emission-related but not severe enough to immediately damage the
TWC) occurs within the first 1,000 engine revolutions after engine start-up, a Temporary DTC is stored.

If a type 2 misfire occurs after the first 1,000 engine revolutions after engine start-up, a Temporary DTC is
stored during the fourth type 2 misfire occurrence.

If a type 2 misfire occurs during the next (second) drive cycle, 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 drive cycles in which the
engine conditions are similar to the first time the malfunction was detected.

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 P0301 (71), P0302 (72), P0303 (73), P0304 (74), P0305 (75), P0306
(76): ADVANCED DIAGNOSTICS

DTC P0301: NO. 1 CYLINDER MISFIRE DETECTED; DTC P0302: NO. 2 CYLINDER MISFIRE
DETECTED; DTC P0303: NO. 3 CYLINDER MISFIRE DETECTED; DTC P0304: NO. 4
CYLINDER MISFIRE DETECTED; DTC P0305: NO. 5 CYLINDER MISFIRE DETECTED; DTC
P0306: NO. 6 CYLINDER MISFIRE DETECTED

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:03 PM

Page 69

Fig. 49: Crankshaft Position Sensor Pulse Data

General Description

The crankshaft vibrates slightly when each cylinder fires. If a misfire occurs, the crankshaft rotation speed
changes rapidly. The powertrain control module (PCM) monitors engine misfiring based on the output
pulses from the crankshaft position (CKP) sensor, counts the number of misfires, and determines which
cylinder is misfiring. If a misfire is detected, a DTC is stored.

There are two types of misfire detection.

Type 1 (1 drive cycle): When the number of misfires per 200 engine revolutions reaches the level that
damages the three way catalyst (TWC), a DTC is stored and the MIL blinks. When the misfire ceases, the
MIL remains on steady instead of blinking.

Type 2 (2 drive cycles): When the number of misfires per 1,000 engine revolutions reaches the level that
affects FTP mode exhaust emissions, a DTC is stored and the MIL comes on.

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Execution

Continuous

Sequence

None

Duration

Type 1 Every 200 rpm
Type 2 Every 1,000 rpm

DTC Type

Two drive cycles, MIL ON

OBD Status

PASSED/FAILED/EXECUTING/OUT OF (TEST) CONDITION

Condition

Minimum

Maximum

Engine coolant temperature

14°F (-10°C)

(1)

68°F (20°C)

(2)

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:03 PM

Page 70

Malfunction Threshold

The number of misfires versus engine revolutions is equal to or greater than the values in the table.

MALFUNCTION THRESHOLD

Driving Pattern

Fig. 50: Vehicle Speed 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.

2. Drive the vehicle at a speed between 15 - 75 mph (24 - 120 km/h) for at least 3 minutes.

Engine speed

500 rpm

6,800 rpm

MAP value

(3)

500 rpm

23 kPa (6.7 in.Hg, 170
mmHg)

2,000 rpm

22 kPa (6.5 in.Hg, 165
mmHg)

Fuel feedback

Other than during fuel cut-off operation

No active DTCs

P0107, P0108, P0117, P0118, P0122, P0123,
P0222, P0223, P0335, P0339, P0385, P0389,
P1109, P1128, P1129, P2227, P2228, P2229

Other

Test-drive on a flat road to avoid misdetection

(1)

When starting the engine at an engine coolant temperature of 14°F (-10°C) or less.

(2)

When starting the engine at an engine coolant temperature of more than 14°F (-10°C).

(3)

Varies with driving conditions.

Misfire Type

The number of engine revolutions

The number of misfires

Misfire Type 1 (Severe)

Per 200 revolutions

26 - 89 times

(1)

Misfire Type 2 (Light)

Per 1,000 revolutions

54 times

(1)

Depending on engine speed and load.

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:03 PM

Page 71

3. Stop the vehicle, and let the engine idle for at least 3 minutes.



When freeze frame data is stored, drive the vehicle under those conditions instead of Driving Patterns
2 or 3.



When you have difficulty duplicating the DTC because of road conditions and traffic situations,
repeat the driving pattern several times.



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

Diagnosis Details

Conditions for illuminating the MIL

If a type 2 misfire occurs after the first 1,000 engine revolutions after engine start-up, a Temporary DTC is
stored during the fourth type 2 misfire occurrence.

If a type 2 misfire occurs during the next (second) drive cycle, 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 drive cycles in which the
engine conditions are similar to the first time the malfunction was detected.

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 P0325 (23): ADVANCED DIAGNOSTICS

DTC P0325: KNOCK SENSOR (KS) CIRCUIT MALFUNCTION

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

Friday, June 05, 2009 2:32:03 PM

Page 72

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