4WD Control Unit
Remove radio and remove 4WD control unit. Disconnect control unit harness connector. Backprobe harness connector. Check voltage between each individual terminal and ground terminal No. 8 (Black wire). See Fig 1 and 4WD CONTROL UNIT PIN VOLTAGE CHART . If after all tests have been completed system is not operating properly, substitute 4WD control unit with known-good unit and retest.
4WD CONTROL UNIT PIN VOLTAGE CHART
| Terminal ID (Wire Color) | Function/Description | Voltage Value (DC Volts Unless Otherwise Specified) |
|---|---|---|
| 1 (Yellow/Blue) | HI/LO Detection Switch | KOEO - 9-11 Volts With Transfer In "N" |
| 1 (Yellow/Blue) | HI/LO Detection Switch | KOEO - 0 Volt In "4HLc" Or "4LLc" |
| 2 (Blue/Orange) | 4WD Operation Detection Switch | KOEO - 9-11 Volts In "2H" |
| 2 (Blue/Orange) | 4WD Operation Detection Switch | KOEO - 0 Volt "4H" |
| 3 (Blue/Yellow) | Ignition Switch (IG2) | Ignition Off - 0 Volt |
| 3 (Blue/Yellow) | Ignition Switch (IG2) | Ignition On - Battery Voltage |
| 4 (Blue/Green) | Center Differential Lock Indicator Light | KOEO - Battery Voltage With Transfer In "4H" |
| 4 (Blue/Green) | Center Differential Lock Indicator Light | KOEO - 0-1.5 Volts With Transfer In "4HLc" |
| 5 (Blue/White) | Center Differential Lock Detection Switch | KOEO - 9-11 Volts With Transfer In "4H" |
| 5 (Blue/White) | Center Differential Lock Detection Switch | KOEO - 0 Volt With Transfer In "4HLc" |
| 6 (Yellow/Green) | Free Wheel Engage Switch | KOEO - 9-11 Volts With Vehicle in 2WD |
| 6 (Yellow/Green) | Free Wheel Engage Switch | KOEO - 0 Volt With Vehicle in 4WD |
| 7 (Yellow/Blue) | Center Differential Lock Operation Detection Switch | KOEO - 9-11 Volts With Transfer In "4H" |
| 7 (Yellow/Blue) | Center Differential Lock Operation Detection Switch | KOEO - 0 Volt With Transfer In "4HLc" |
| 9 (Yellow/Black) | Rear Wheel Indicator Light | KOEO - 0 Volt With Transfer In "N" |
| 9 (Yellow/Black) | Rear Wheel Indicator Light | KOEO - 9-11 Volts In "4HLc" Or "4LLc" |
| 10 (Yellow/Red) | Front Wheel Indicator Light | KOEO - 0 Volt With Vehicle In 2WD |
| 10 (Yellow/Red) | Front Wheel Indicator Light | KOEO - 9-11 Volts With Vehicle In 4WD |