Four-Wheel Drive Does Not Engage. Chevrolet Tracker

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2001 🢒 Tracker - 4WD 🢒 Driveline/Axle 🢒 Transfer Case - Tracker 🢒 Four-Wheel Drive Does Not Engage

Step	Action	Yes	No
Schematic Reference: Transfer Case Control Schematics DEFINITION: 4WD does not engage, all other engine and transmission functions are normal.
1	Did you review the Transfer Case Description and Operation and perform the necessary inspections?	Go to Step 2	Go to Symptoms - Transfer Case
2	Start the engine. Place the transfer case in 4WD and test the vehicle. Does the 4WD system engage?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Test for voltage at the four wheel drive switch signal circuit at the powertrain control module (PCM) connector. Shift the vehicle in and out of 4WD. Does the voltage fluctuate between 0 and 12 volts when shifting in and out of 4WD?	Go to Step 6	Go to Step 4
4	Test the four wheel drive switch ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 5
5	Test the four wheel drive switch signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 8
6	Test the axle pump ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 7
7	Test the axle pump control circuits for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 9
8	Inspect for a poor connection at the harness connector of the four wheel drive switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 10
9	Inspect for a poor connection at the harness connector of the front drive axle actuator pump. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 11
10	Replace the four wheel drive switch. Did you complete the replacement?	Go to Step 12	--
11	Replace the axle pump. Refer to Electric Motor Actuator Replacement in Front Axle Drive. Did you complete the replacement?	Go to Step 12	--
12	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3