Headlight Leveling Control Unit Input Test/Replacement
WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
- Turn the ignition switch to LOCK (0) and open the glove box.
- Remove the glove box stop on right side, then let the glove box hang down (see GLOVE BOX REMOVAL/INSTALLATION ).
- Disconnect the 16P connector (A) from the headlight leveling control unit (B).
- Remove the harness clip and two screws, then remove the unit from the blower unit.
- 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 6.
- With the connector still disconnected, do the following input tests:
- 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 7.
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 terminals No. 15 (+) and No. 9 There should be at least 0-5 V and at least 0-5 V repeatedly. - Faulty PCM
- An open or high resistance in the wire
- A short to ground in the wire
16 LT BLU 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 or high resistance in the wire - Reconnect the connector, turn the ignition switch to ON (II), and do the following input tests:
- If any test indicate a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, replace the headlight leveling control unit.
NOTE: After replacing the control unit, do the headlight initial position learning procedureCavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained 9 BLK In all ignition switch positions Measure the voltage to ground:
There should be less than 0.2 V.- Poor ground (G401) or an open in the ground wire
- An open or high resistance in the wire
3 GRN In all ignition switch positions Measure the voltage to ground:
There should be less than 0.2 V.- Poor ground (G401) or an open in the ground wire
- An open or high resistance in the wire
4 LT GRN 12 BLU 8 RED Headlight switch (high beam) ON Measure the voltage to ground:
There should be battery voltage.- Blown No. 3 (10 A) fuse in the main under-hood fuse box
- Faulty main under-hood fuse box
- An open or high resistance in the wire
1 RED Ignition switch ON (II) Measure the voltage to ground:
There should be battery voltage.- Blown No. 31 (15 A) fuse in the under-dash fuse/relay box
- An open or high resistance in the wire
2 BLU Ignition switch ON (II), headlight switch ON Measure the voltage between terminals No. 2 and No. 3:
There should be battery voltage.- Faulty headlight leveling motor
- An open or high resistance in the wire
3 GRN 11 BRN Ignition switch ON (II), headlight switch ON Measure the voltage between terminals No. 11 and No. 3:
There should be about 2 to 12 V.- Faulty headlight leveling motor
- An open or high resistance in the wire
3 GRN 6 PUR Under all conditions - Measure the voltage between terminals No. 13 and No. 12: There should be about 5 V.
- Measure the voltage between terminals No. 6 and No. 12: There should be about 0.5 to 4.5 V.
- Faulty left-front suspension stroke sensor
- An open or high resistance in the wire
12 BLU 13 PNK 4 LT GRN Under all conditions - Measure the voltage between terminals No. 5 and No. 4: There should be about 5 V.
- Measure the voltage between terminals No. 7 and No. 4: There should be about 0.5 to 4.5 V.
- Faulty left-rear suspension stroke sensor
- An open or high resistance in the wire
5 RED 7 LT BLU