Pinpoint Test "C" Cannot Engage 4WD DTC P1833, P1834, P1842,

P1845

1. Check Fuse 26
   
   Check fuse No. 26 for open. If fuse is okay, go to next step. If fuse is blown, replace fuse and go to step 4).
2. Check Dark Blue/Yellow Wire For Open
   
   Turn ignition off. Disconnect GEM harness connector C3. Disconnect 4X4 center axle connect solenoid harness connector (located in right/front of engine compartment). Check continuity of Dark Blue/Orange wire between GEM harness connector C3 terminal No. 7 and center axle solenoid harness connector. If continuity exists, go to next step. If continuity does not exist, repair Dark Blue/Orange wire for open. Clear and recheck for DTCs.
3. Check Center Axle Connect Solenoid
   
   Disconnect 4X4 center axle connect solenoid (located in right/front of engine compartment). Measure resistance across solenoid terminals. If resistance is 55-95 ohms, solenoid is okay. Restore all electrical connections. Clear and recheck for DTCs. If resistance is not 55-95 ohms, replace 4X4 center axle connect solenoid. Restore all electrical connections. Clear and recheck for DTCs.
4. Check Dark Blue/Yellow Wire For Short To Ground
   
   Check for continuity between Dark Blue/Yellow wire at GEM harness connector C3 terminal No. 7 and ground. See Figure . If continuity exists, repair Dark Blue/Orange wire for short to ground. If continuity does not exist, replace GEM with known good unit. Clear and recheck for DTCs.
5. Check Brown Wire For Short To Power
   
   Disconnect GEM harness connector C3. See Figure . Turn ignition on. Measure voltage between GEM harness connector C3 terminal No. 4 and ground. If battery voltage does not exist, go to next step. If battery voltage exists, repair Brown wire for short to power. Clear and recheck for DTCs.
6. Check Brown Wire For Open
   
   Disconnect GEM harness connector C3. Disconnect front axle disconnect switch (located on front axle). Check continuity of Brown wire between GEM harness connector C3 terminal No. 4 and front axle disconnect switch. If continuity exists, go to next step. If continuity does not exist, repair open Brown. Clear and recheck for DTCs.
7. Check Brown Wire For Short To Ground
   
   Disconnect GEM harness connector C3. Disconnect front axle disconnect switch (located on front axle). Check continuity of Brown wire between GEM harness connector C3 terminal No. 4 and ground. If continuity does not exist, go to next step. If continuity exists, repair Brown wire for short to ground.
8. Check Front Axle Disconnect Switch
   
   Disconnect front axle disconnect switch (located on front axle). Measure resistance across terminals of front axle disconnect switch. If resistance is greater than 100 k/ohms, switch is okay. Clear and recheck for DTCs. If resistance is less than 100 k/ohms, replace front axle disconnect switch. Clear and recheck for DTCs.