Content .. 5 6 7 8 ..

Acura RL. Manual - part 7

seconds.

Driving Pattern

Fig. 20: 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 steady speed up to 25 mph (40 km/h), for at least 5 minutes.

3. Then, drive immediately at a steady speed between 26 - 81 mph (41 - 130 km/h) for at least 6.8

seconds.



If the EVAP monitor runs instead of the HO2S monitor, turn the engine off, then restart it, and the
HO2S monitor will restart.



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

Diagnosis Details

Conditions for illuminating the MIL

When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the PCM
memory. If the malfunction recurs 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 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 P0134 (151): ADVANCED DIAGNOSTICS

DTC P0134: REAR AIR/FUEL RATIO (A/F) SENSOR (BANK 1, SENSOR 1) HEATER SYSTEM

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 25

MALFUNCTION

Fig. 21: Rear Air/Fuel Ratio Sensor (Bank 1, Sensor 1) Heater System Malfunction Determination

General Description

The rear air/fuel ratio (A/F) sensor (bank 1, sensor 1) is activated by warming the element with the heater
any by maintaining it at a steady high temperature to accurately calculate the air/fuel (A/F) ratio. The rear
A/F sensor does not become active when the element is not properly heated due to a heater malfunction, and
the exhaust emissions deteriorate. The powertrain control module (PCM) monitors the rear A/F sensor
internal resistance.

1. When the rear A/F sensor does not activate within a set time after the rear A/F sensor heater starts to

warm up (with high rear A/F sensor internal resistance), a malfunction of the rear A/F sensor heater is
detected, and a DTC is stored.

2. When the rear A/F sensor heater cycles ON and OFF within a set time, and the resistance remains

high when the heater is ON, a malfunction in the rear A/F sensor heater is detected, and a DTC is
stored.

Because the effect engine control differs according to the rear A/F sensor internal resistance, there are
two types of malfunction detection threshold levels. When either one is reached, a malfunction is
detected.

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

Page 26

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

MONITOR DESCRIPTION CHART

Enable Conditions

ENABLE CONDITIONS

Malfunction Threshold

Malfunction determination 1

The rear A/F sensor (bank 1, sensor 1) internal resistance value is 110 ohms or more for at least 40 seconds
right after the engine starts.

Malfunction determination 2



The rear A/F sensor (bank 1, sensor 1) internal resistance value is 110 ohms or more for at least 15
seconds.



The rear A/F sensor (bank 1, sensor 1) internal resistance value is 200 ohms or more for at least 1
second.

Driving Pattern

Start the engine, then let it idle for at least 2 minutes.

Diagnosis Details

Conditions for illuminating the MIL

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

Execution

Continuous

Sequence

None

Duration

40 seconds or more

DTC Type

Two drive cycles, MIL ON

OBD Status

PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Condition

Minimum

Maximum

Battery voltage 10.5 V

Fuel feedback

Other than during fuel cut-off operation

No active DTCs P0135, P1172, P2195, P2237, P2238, P2243, P2245, P2251, P2252, P2627, P2628

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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Page 27

Clear command or by disconnecting the battery.

DTC P0135 (151): ADVANCED DIAGNOSTICS

DTC P0135: REAR AIR/FUEL RATIO (A/F) SENSOR (BANK 1, SENSOR 1) HEATER CIRCUIT
MALFUNCTION

Fig. 22: Rear Air/Fuel Ratio Sensor (Bank 1, Sensor 1) Heater - Circuit Diagram

General Description

The rear air/fuel ratio (A/F) sensor (bank 1, sensor 1) is installed in the exhaust manifold, and it detects
oxygen content in the exhaust gas. The rear A/F sensor outputs voltage to the powertrain control module
(PCM). The PCM controls fuel injection time by comparing the target air/fuel ratio with the rear A/F sensor
signal. The sensor includes the VS cell, the pump cell, the atmospheric reference cavity, the diffusion layer,
and the heater, and it enables overall feedback control. The heater is controlled by the PCM and is energized
when the sensor element temperature is low. It heats the sensor to stabilize the detection of oxygen content.
The PCM monitors the rear A/F sensor heater output (return check). A malfunction is detected if the return
signals do not meet the command value (for heater activation) in the PCM for a set time or more and a DTC
is stored.

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

MONITOR DESCRIPTION CHART

Execution

Continuous

Sequence

None

Duration

2 seconds or more

2007 Acura RL

2007 ENGINE PERFORMANCE Advanced Diagnostics - RL

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

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