Acura RL. Manual - part 21

When the engine starts, the rotor turns and the magnetic flux in the semiconductor changes. The changes of
magnetic flux are converted into pulsing signals to the powertrain control module (PCM). CKP sensor B
detects injection/ignition timing for each cylinder and engine speed.

If no pulsing signals are detected from CKP sensor B, a malfunction is detected and a DTC is stored.

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Malfunction Threshold

No signals from CKP sensor B are detected while signals from CKP sensor A are detected 352 times in
succession.

Diagnosis Details

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 P0389 (54): ADVANCED DIAGNOSTICS

DTC P0389: CRANKSHAFT POSITION (CKP) SENSOR B INTERMITTENT INTERRUPTION

Execution

Continuous

Sequence

None

Duration

DTC Type

One drive cycle, MIL ON

OBD Status

N/A

Condition

State of the engine

Running

No active DTCs

P0335, P0339

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 81

Fig. 57: Crankshaft Position Sensor B - Circuit Diagram

General Description

Crankshaft position (CKP) sensor B consists of a rotor and a semiconductor that detects rotor position.
When the engine starts, the rotor turns and the magnetic flux in the semiconductor changes. The changes of
magnetic flux are converted into pulsing signals to the powertrain control module (PCM). CKP sensor B
detects injection/ignition timing for each cylinder and engine speed.

If an abnormal amount of pulsing signals are detected from CKP sensor B, a malfunction is detected and a
DTC is stored.

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Execution

Continuous

Sequence

None

Duration

DTC Type

One drive cycle, MIL ON

OBD Status

N/A

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 82

Malfunction Threshold

Other than 22 pulses are detected during intervals between reference pulses for each crankshaft revolution.
This condition has been detected at least 30 times.

Diagnosis Details

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 P0401 (80): ADVANCED DIAGNOSTICS

DTC P0401: EXHAUST GAS RECIRCULATION (EGR) INSUFFICIENT FLOW

Fig. 58: Exhaust Gas Recirculation Insufficient Flow Diagram

Condition

State of the engine

Running

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 83

Fig. 59: Exhaust Gas Recirculation Valve Normal Operation And System Failure Diagram

General Description

The exhaust gas recirculation (EGR) valve is controlled by the powertrain control module (PCM). When the
valve is opened, the exhaust gas flows from the exhaust manifold to the intake manifold through the EGR
system. It is mixed with the air/fuel mixture to be drawn into the combustion chamber to lower peak
combustion temperature to reduce NOx.

The EGR flow is inspected as follows. The EGR valve is closed during deceleration with the throttle valve
fully closed. Then the PCM fully opens the EGR valve. After a set time, the PCM computes the ratio of the
present EGR flow to the normal EGR flow by monitoring the fluctuation of the intake manifold pressure
between when the EGR valve is fully opened and when it is fully closed. If the EGR flow rate is lower than
normal, a malfunction is detected and a DTC is stored.

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Execution

Once per driving cycle

Sequence

"EGR valve insufficient lift" P0404, P2413 is OK

Duration

3 seconds or more

DTC Type

Two drive cycles, MIL ON

OBD Status

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

Condition

Minimum

Maximum

Engine coolant temperature

156°F (69°C)

Engine speed

1,100 rpm

2,400 rpm

MAP value

12 kPa (3.6 in.Hg, 90 mmHg)

Vehicle speed

30 mph (48 km/h)

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 84

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