Scheme 1
The headlight leveling system is composed of the headlight leveling control unit, the suspension stroke sensor, and the left and right headlight leveling motors.
The system uses the suspension stroke sensor to monitor the vehicle ride height. The ride height is monitored every 3 minutes while the vehicle is running with the headlight switch ON, and 8 seconds after the vehicles stops with the ignition and headlight switches ON.
If the control unit detects a ride height change, the control unit controls the headlight leveling motors to adjust the headlight vertical position.
Scheme 2
Suspension Stroke Sensor
The suspension stroke sensor detects the vehicle posture and send a voltage signal (about 0.4-4.6 V) to the headlight leveling control unit.
Headlight Leveling Control Unit
The headlight leveling control unit is located under the driver's side of the dashboard. The headlight leveling control unit uses the voltage signals it receives from the suspension stroke sensor to determine the voltage signal (about 2-11 V) it sends to control the left and right leveling motors.
Headlight Leveling Motors
The headlight leveling motors are located behind both headlights, and they adjust the headlights vertically based upon the voltage signals (about 2-11 V) they receive from the headlight leveling control unit.
Headlight Initial Position Learning Procedure
Do the headlight initial position learning when any of the related parts of the headlight leveling system shown is removed or replaced
- Suspension stroke sensor removed or replaced
- Headlight leveling control unit replaced
Learning Procedure
Before learning the headlights
- Park the vehicle on a level surface.
- Make sure the tire pressures are correct.
- Turn the ignition switch to LOCK (0).
- Remove all of the baggage from the vehicle.
- Slide the front seats backward fully.
- Have the driver (about 165 lb (75 kg)) or someone who weighs the same sit in the driver's seat.
- Connect the HDS to the data link connector.
- Turn the ignition switch to ON (II).
- Jump the SCS line with the HDS.
- Turn the ignition switch to LOCK (0), and then back to ON (II).
- Within 5 seconds, turn the headlights (low beam) or passing switch ON and OFF three times repeatedly, and leave them on. If the headlights move down (about 2 in. at 10 feet), then return to the original position, the initial position learning is complete. If the headlights don't move, go to step 1 and repeat the procedure.
- Turn the ignition switch to LOCK (0), and disconnect the HDS from the data link connector.
- Adjust the headlight aim to conform with the applicable requirements.
Scheme 3
Scheme 4
Scheme 5
- Turn the ignition switch to LOCK (0).
- Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rl/ii-2008-2012/remont/exteriorinterior-trim/#dashboard) ), and the driver's dashboard lower cover (see «DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION»(/acura/rl/ii-2008-2012/remont/exteriorinterior-trim/#dashboard) ).
- Disconnect the 16P connector (A) from the headlight leveling control unit (B).
- Inspect the connector and socket terminals to be sure they are all making good contact. If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system. If the terminals are OK, go to step 5 .
- With the connector still disconnected, do these input tests at the connector. If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, go to step 6 . WIRE TEST CONDITION REFERENCE TABLE Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 15 BLU Ignition switch ON (II), raise the vehicle, make sure it is securely supported, and rotate one of the front wheels slowly with the other wheel blocked. Measure the voltage between the terminals No. 15 (+) and No. 9 (-): There should be about 0-5 V or more and 0-5 V or more repeatedly. Faulty PCM An open in the wire A short to ground in the wire 16 GRN Under all conditions Check for continuity between terminal No. 16 and combination switch control unit 8P connector terminal No. 2: There should be continuity. An open in the wire
- Reconnect the connector to the control unit, and do these input tests at the connector. If any tests indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, replace the headlight leveling control unit. WIRE TEST CONDITION REFERENCE TABLE Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 1 BLU Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage. Blown No. 29 (7.5 A) fuse in the driver's under-dash fuse/relay box An open in the wire 9 BLK Under all conditions Measure the voltage to ground: There should be less than 0.1 V. Poor ground (G401) An open in the wire 4 LT BLU Under all conditions Measure the voltage to ground: There should be less than 0.1 V. Poor ground (G401) An open in the wire 2 YEL Ignition switch ON (II), headlight ON Measure the voltage between terminals No. 2 and No. 3: There should be battery voltage. Faulty headlight leveling motor An open in the wire 3 RED 11 PNK Ignition switch ON (II), headlight ON Measure the voltage between terminals No. 11 and No. 3: There should be about 2 V to 12 V. Faulty headlight leveling motor An open in the wire 3 RED 5 GRY Under all conditions Measure the voltage between the terminals No. 5 (+) and No. 4 (-): There should be about 5 V. Measure the voltage between the terminals No. 7 (+) and No. 4 (-): There should be about 0.5 V to 4.5 V. Faulty suspension stroke sensor An open in the wire 7 PUR 4 LT BLU
- After replacing the control unit, do «HEADLIGHT INITIAL POSITION LEARNING PROCEDURE»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system__headlight-initial-position-learning-procedure) .
Scheme 6
- Turn the ignition switch to LOCK (0).
- Disconnect the 3P connector (A) from the headlight leveling motor (B).
- Inspect the connector and socket terminals to be sure they are all making good contact. If the terminals are bent, loose, or corroded, repair them as necessary, and recheck the system. If the terminals are OK, go to step 4 .
- Reconnect the connector to the headlight leveling motor, and do these input tests at the connector. If any tests indicate a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, replace the headlight leveling motor (see «HEADLIGHT LEVELING MOTOR REPLACEMENT»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system) ). WIRE TEST CONDITION REFERENCE TABLE Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 1 YEL Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage. Faulty headlight leveling control unit An open in the wire 2 PNK Ignition switch ON (II), turn the headlight switch ON Measure the voltage to ground: There should be about 2-12 V. Note: Depending on the headlight leveling position. Poor ground (G401) Faulty headlight leveling control unit An open in the wire 3 RED Ignition switch ON (II) Measure the voltage to ground: There should be less than 0.1 V. Faulty headlight leveling control unit An open in the wire
Headlight Leveling Motor Test
Note. Before testing, check the No. 11 (7.5 A) and No. 29 (7.5 A) fuses in the driver's under-dash fuse/relay box.
Scheme 7
- Disconnect the 3P connector (A) from the headlight leveling motor (B).
- Check for continuity between headlight leveling motor 3P connector terminal No. 3 and body ground. There should be continuity. If there is continuity, go to step 3 . If there is no continuity, check for: Faulty adaptive front lighting control unit. An open in the wire between the adaptive front lighting control unit and the headlight leveling motor. Poor ground (G401).
- Turn the ignition switch to ON (II).
- Measure the voltage between headlight leveling motor 3P connector terminal No. 1 and body ground. There should be battery voltage. If there is battery voltage, go to step 5 . If there is no voltage, check for: Faulty adaptive front lighting control unit. An open in the wire between the adaptive front lighting control unit and the headlight leveling motor.
- Turn the headlight switch ON.
- Measure the voltage between headlight leveling motor 3P connector terminal No. 2 and body ground. There should be about 3-13 V. NOTE: The voltage will vary depending on the vehicle position. If there is battery voltage, replace the headlight leveling motor (see «HEADLIGHT LEVELING MOTOR REPLACEMENT»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system) ). If there is no voltage, check for: Faulty adaptive front lighting control unit. An open in the wire between the adaptive front lighting control unit and the headlight leveling motor.
Scheme 8
- Remove the suspension stroke sensor (see «SUSPENSION STROKE SENSOR REPLACEMENT»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system) ).
- Measure the resistance between suspension stroke sensor 3P connector terminals No. 1 and No. 3. There should be about 3.5-6.5 kohms.
- Measure the resistance between suspension stroke sensor 3P connector terminals No. 2 and No. 3 with the linkage (A) moved. There should be about 0.5-4.5 kohms.
- If the resistance is not as specified, replace the suspension stroke sensor (see «SUSPENSION STROKE SENSOR REPLACEMENT»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system) ).
Scheme 9
- Lift the vehicle, and support it with safety stands (see «LIFT AND SUPPORT POINTS»(/acura/rl/ii-2008-2012/remont/hoistjack/#general-information__lift-and-support-points) ).
- Disconnect the 3P connector (A) from the suspension stroke sensor (B).
- Remove the bolts and nut, then remove the suspension stroke sensor.
- Install the sensor in the reverse order of removal.
- After replacement, do «HEADLIGHT INITIAL POSITION LEARNING PROCEDURE»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system__headlight-initial-position-learning-procedure) .
Scheme 10
Scheme 11
- Remove the headlight assembly (see «HEADLIGHT REPLACEMENT»(/acura/rl/ii-2008-2012/remont/exterior-lights/#exterior-lights) ).
- Turn the HID light cover 45° counterclockwise to remove it from the headlight housing (see «BULB REPLACEMENT»(/acura/rl/ii-2008-2012/remont/exterior-lights/#exterior-lights) ).
- Turn the leveling motor (A) 45° clockwise.
- Pull the headlight reflector (A) slightly, and remove the headlight leveling motor (B).
- Install the parts in the reverse order of removal.
- After installation, do «HEADLIGHT INITIAL POSITION LEARNING PROCEDURE»(/acura/rl/ii-2008-2012/remont/headlights/#headlight-leveling-system__headlight-initial-position-learning-procedure) .