Automatic Lighting Control Unit Input Test

1. Remove the driver's dashboard lower cover.

1. Disconnect the 14P connector (A) from the automatic lighting control unit (B).

1. 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 look OK, go to Step 4 .

1. Make these input tests at the connector.
   - If any test indicates a problem, find and correct the cause, then recheck the system.
   - If all input tests prove OK, the control unit must be faulty; replace it.

   Cavity | Wire | Test condition | Test: Desired result | Possible cause if result is not obtained
   --- | --- | --- | --- | ---
   7 | YEL | Ignition switch ON (II) or START (III) | Check for voltage to ground: There should be battery voltage. |
   - Blown No. 21 (10 A) fuse in the driver's under-dash fuse/relay box
   - An open in the wire
   1 | WHT | Ignition switch ON (II) |
   - Blown No. 7 (7.5 A) fuse in the driver's under-dash fuse/relay box
   - An open in the wire
   4 | LT GRN | Combination switch in the OFF, PARK, and AUTO positions | Check for voltage to ground: There should be battery voltage. |
   - Faulty headlight relay 1 or 2
   - An open in the wire
   8 | BLK | Under all conditions | Check for continuity to ground: There should be continuity. |
   - Poor ground (G506)
   - An open in the wire
   9
   11 | BLU | Driver's door open * | Check for voltage to ground: There should be 1 V or less. |
   - Faulty driver's door switch
   - An open in the wire
   2 | WHT | Combination light switch ON (Except ‘‘AUTO'') | Check for continuity to ground: There should be continuity. |
   - Faulty combination light switch
   - Poor ground (G501, G601)
   - An open in the wire

   *: | Reconnect the 14P connector to the control unit

   NOTE: Before testing, connect a voltmeter and jumper wires as shown:

Cavity | Wire | Test condition | Test: Desired result | Possible cause if result is not obtained
--- | --- | --- | --- | ---
6 | RED | Cover the automatic lighting sensor * | Check for voltage between the No. 6 terminal and body ground: There should be 1 V or less. |

- Faulty automatic lighting sensor
- An open in the wire

Shine light on the automatic lighting sensor | Check for voltage between the No. 6 terminal and body ground: There should be 5 V or more. |

- Faulty automatic lighting sensor
- An open in the wire

*: | The automatic lighting sensor is located in the middle of dashboard. Cut the light off completely with a dark cloth.