Acura RL. Manual - part 506

DTC TROUBLESHOOTING CHART 

Low Voltage

P2229 (13)

--

Barometric Pressure 
(BARO) Sensor Circuit 
High Voltage

ON

P2237 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
IP Circuit High Voltage

ON

P2238 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
IP Circuit Low Voltage

ON

P2240 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
IP Circuit High Voltage

ON

P2241 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
IP Circuit Low Voltage

ON

P2243 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
VCENT Circuit High 
Voltage

ON

P2245 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
VCENT Circuit Low 
Voltage

ON

P2247 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
VCENT Circuit High 
Voltage

ON

P2249 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
VCENT Circuit Low 
Voltage

ON

NOTE:

The above DTCs are indicated when the PGM-FI system is selected in the HDS. 
Some automatic transmission DTCs cause the MIL to come on. If the MIL is on and no DTCs are 
indicated in the PGM-FI system, select the A/T system, and check for automatic transmission 
DTCs.

(1)

These DTCs are indicated by a blinking MIL when the SCS line is jumped with the HDS.

DTC (MIL indication

(1)

)

Two Drive Cycle 

Detection

Detection Item

MIL

P2251 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
VS Circuit High Voltage

ON

P2252 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 

ON

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

  

me 

 

Friday, June 05, 2009 2:33:27 PM

Page 19 

© 2005 Mitchell Repair Information Company, LLC. 

VS Circuit Low Voltage

P2254 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
VS Circuit High Voltage

ON

P2255 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
VS Circuit Low Voltage

ON

P2270 (161)

o 

(2)

Rear Secondary Heated 
Oxygen Sensor 
(Secondary HO2S (Bank 
1, Sensor 2)) Circuit 
Signal Stuck Lean

ON

P2271 (161)

o 

(2)

Rear Secondary Heated 
Oxygen Sensor 
(Secondary HO2S (Bank 
1, Sensor 2)) Circuit 
Signal Stuck Rich

ON

P2272 (162)

o 

(2)

Front Secondary Heated 
Oxygen Sensor 
(Secondary HO2S (Bank 
2, Sensor 2)) Circuit 
Signal Stuck Lean

ON

P2273 (162)

o 

(2)

Front Secondary Heated 
Oxygen Sensor 
(Secondary HO2S (Bank 
2, Sensor 2)) Circuit 
Signal Stuck Rich

ON

P2279 (109)

o

Intake Air System Leak

ON

P2413 (12)

o

Exhaust Gas Recirculation 
(EGR) System 
Malfunction

ON

P2422 (117)

o

Evaporative Emission 
(EVAP) Canister Vent 
Shut Valve Close 
Malfunction

ON

P2552 (40)

--

Throttle Actuator Control 
Module Relay 
Malfunction

ON

P2610 (132)

--

Powertrain Control 
Module (PCM) Internal 
Power Off Timer 
Malfunction

ON

P2627 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
LABEL Circuit Low 
Voltage

ON

P2628 (155)

--

Rear Air Fuel Ratio (A/F) 
Sensor (Bank 1, Sensor 1) 
LABEL Circuit High 

ON

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

  

me 

 

Friday, June 05, 2009 2:33:27 PM

Page 20 

© 2005 Mitchell Repair Information Company, LLC. 

Voltage

P2630 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
LABEL Circuit Low 
Voltage

ON

P2631 (156)

--

Front Air Fuel Ratio (A/F) 
Sensor (Bank 2, Sensor 1) 
LABEL Circuit High 
Voltage

ON

P2646 (22)

--

Rocker Arm Oil Pressure 
Switch (VTEC Oil 
Pressure Switch) Circuit 
Low Voltage

ON

P2647 (22)

--

Rocker Arm Oil Pressure 
Switch (VTEC Oil 
Pressure Switch) Circuit 
High Voltage

ON

P2648 (21)

--

Rocker Arm Oil Control 
Solenoid (VTEC Solenoid 
Valve) Circuit Low 
Voltage

ON

P2649 (21)

--

Rocker Arm Oil Control 
Solenoid (VTEC Solenoid 
Valve) Circuit High 
Voltage

ON

P2A00 (157)

o 

(2)

Rear Air Fuel Ratio (A/F) 
Sensor Circuit 
Range/Performance 
Problem (Bank 1, Sensor 
1)

ON

P2A03 (158)

o 

(2)

Front Air Fuel Ratio (A/F) 
Sensor Circuit 
Range/Performance 
Problem (Bank 2, Sensor 
1)

ON

U0073 (126)

--

F-CAN Malfunction 
(BUS-OFF)

ON

U0104 (126)

(2)

--

F-CAN Malfunction 
(Adaptive Cruise Control 
(ACC) Unit-PCM)

OFF

U0107 (30)

--

Lost Communication 
With Throttle Actuator 
Control Module

ON

U0114 (126)

--

F-CAN Malfunction (SH-
AWD Control Unit-PCM)

OFF

U0122 (126)

--

F-CAN Malfunction 
(VSA Modulator-Control 
Unit-PCM)

OFF

U0155 (126)

--

F-CAN Malfunction 

ON

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

  

me 

 

Friday, June 05, 2009 2:33:27 PM

Page 21 

© 2005 Mitchell Repair Information Company, LLC. 

SYMPTOM TROUBLESHOOTING INDEX 

When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the HDS. If 
there is no DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the 
cause. 

DTC TROUBLESHOOTING CHART 

(Gauge Control Module-
PCM)

NOTE:

The above DTCs are indicated when the PGM-FI system is selected in the HDS. 
Some automatic transmission DTCs cause the MIL to come on. If the MIL is on and no DTCs are 
indicated in the PGM-FI system, select the A/T system, and check for automatic transmission 
DTCs.

(1)

These DTCs are indicated by a blinking MIL when the SCS line is jumped with the HDS.

(2)

'06-08 models

Symptom

Diagnostic procedure

Also check for

Engine will not start (MIL 
works OK, no DTCs set)

1. Test the battery (see 

BATTERY TEST ).  

2. Test the starter (see 

STARTER 
PERFORMANCE TEST ).  

3. Check the fuel pressure (see 

FUEL PRESSURE TEST ). 



Low compression  



No ignition spark  



Intake air leaks  



Locked up engine  



Broken timing belt  



Contaminated fuel  

Engine will not start (MIL 
comes on and stays on, or 
never comes on at all, no 
DTCs set)

Troubleshoot the MIL circuit (see 
MIL CIRCUIT 
TROUBLESHOOTING ).

 

MIL comes on and stays on, or 
never comes on at all, no 
DTCs set

Troubleshoot the MIL circuit (see 
MIL CIRCUIT 
TROUBLESHOOTING ).

 

Engine will not start (MIL 
works OK, no DTCs set, 
immobilizer indicator stays on 
or flashes)

Check the immobilizer system.

 

Engine starts but stalls 
immediately (MIL works OK, 
no DTCs set, immobilizer 
indicator stays on or flashes)

Check the immobilizer system.

 

Engine is hard to start (MIL 
works OK, no DTCs set)

1. Test the battery (see 

BATTERY TEST ).  

2. Check the fuel pressure (see 

FUEL PRESSURE TEST ). 

3. Clean the throttle body (see 



Low compression  



Intake air leaks  



Contaminated fuel  



Weak spark  



Restricted exhaust  

 

2007 Acura RL 

2005-08 ENGINE PERFORMANCE Fuel and Emissions Systems - RL

  

me 

 

Friday, June 05, 2009 2:33:27 PM

Page 22 

© 2005 Mitchell Repair Information Company, LLC.