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HOMESERVICE MANUALSCHEVROLET2018SONIC PREMIER, 4D SEDAN, STANDARD TRANSREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 80 (TRANSFER CASE - MP 3025G (NQ6))DIAGNOSTIC INFORMATION AND PROCEDURESDTC C0364 OR C0379: FRONT AXLE SYSTEM/FRONT AXLE SWITCHCIRCUIT/SYSTEM TESTING
2018 Chevrolet Sonic Premier, 4D Sedan, Standard Trans

Circuit/System Testing

2018 Chevrolet Sonic Premier, 4D Sedan, Standard TransSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2017 GMC Canyon and 2017 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the M26 front axle engagement actuator.
  2. Ignition ON, engine OFF.
    3. NOTE:
    • When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J-35616  GM-Approved Terminal Test Kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.
    • Testing for steps 3-11 is performed on the M26 front axle engagement actuator harness connector using the GY probes J-35616-2A.
  3. Test for a True B+ (+0.0/-1.0 V) between the ignition 1 voltage circuit terminal 1 and a good ground, such as the ground terminal of the EL-49742  harness, black terminal.
    • If less than B+ (+0.0/-1.0 V) 
    1. Ignition OFF, remove the F17UA fuse, X50A fuse block - underhood.

      or

      Disconnect the X2 harness connector at the X50A fuse block - underhood.

    2. Test for less than 10 Ω in the run/crank ignition 1 voltage circuit end to end.
      • If 10 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 10 Ω
    3. Test for infinite resistance between the run/crank ignition 1 voltage circuit, terminal 1 and a good ground, such as the ground terminal of the EL-49742  harness, black terminal.
      • If less than infinite resistance, repair the short to ground condition in the circuit.
      • If greater than 10 Ω
    4. Test for greater than 10 Ω between run/crank ignition 1 voltage circuit, terminal 1 and all other terminals of the M26 front axle engagement actuator.
      • If 10 Ω or less, repair the short together condition in the affected circuits.
      • If greater than 10 Ω
    5. Ignition ON.
    6. Test for a less than 1.0 V between the run/crank ignition 1 voltage circuit, terminal 1, and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
      • If 1.0 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the KR73 ignition main relay. Refer to X50A fuse block - underhood label.
    • If B+ (+0.0/-1.0 V) 
  4. Ignition 1 voltage circuit OK.
  5. Test for a true B+ (+0.0/-1.0 V) between the ground circuit, terminal 4, and the run/crank ignition 1 voltage circuit, terminal 1 or the B+ terminal of the EL-49742  harness, red terminal.
    • If less than the B+ (+0.0/-1.0 V) 
    1. Ignition OFF, disconnect the grounding bolt G110. Refer to Ground Views .
    2. Test for less than 10 Ω in the ground circuit end to end.
      • If 10 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 10 Ω
    3. Test for infinite resistance between the ground circuit, terminal 4 and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
      • If 10 Ω or less, repair the short to ground condition in the circuit.
      • If greater than 10 Ω
    4. Test for infinite resistance between ground circuit, terminal 4 and all other terminals of the M26 front axle engagement actuator harness connector.
      • If 1 Ω or less, repair the short together condition in the affected circuits.
      • If greater than 1 Ω
    5. Ignition ON.
    6. Test for a less than 1.0 V between the ground circuit, terminal 4, and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
    • If B+ 
  6. Ground circuit OK.
  7. Test for a diagnostic B+ (+0.0/-1.0 V) between the four wheel drive wheel lock indicator circuit, terminal 3, and the run/crank ignition 1 voltage circuit, terminal 1 or the B+ terminal of the EL-49742  harness, red terminal.
    • If less than B+ (+0.0/-1.0 V) 
    1. Ignition OFF, disconnect the X1 harness connector at the K69 transfer case control module.
    2. Test for less than 10 Ω in four wheel drive wheel lock indicator circuit end to end.
      • If 10 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 10 Ω
    3. Test for infinite resistance between the four wheel drive wheel lock indicator circuit, terminal 3 and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
      • If less than infinite resistance, repair the short to ground condition in the circuit.
      • If greater than 10 Ω
    4. Test for infinite resistance between four wheel drive wheel lock indicator circuit, terminal 3 and all other terminals of the M26 front axle engagement actuator harness connector.
      • If less than infinite resistance, repair the short together condition in the affected circuits.
      • If greater than 10 Ω
    5. Ignition ON.
    6. Test for a less than 1.0 V between the four wheel drive wheel lock indicator circuit, terminal 3, and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
    • If B+ 
  8. Four wheel drive wheel lock indicator circuit OK.
  9. Test for a diagnostic B+ (+0.0/-1.0 V) if in 2WD or, a true B+ (+0.0/-1.0 V) if in 4WD, between the front axle actuator control circuit, terminal 2, and the run/crank ignition 1 voltage circuit, terminal 1 or the B+ terminal of the EL-49742  harness, red terminal.
    • If less than B+ (+0.0/-1.0 V) 
    1. Ignition OFF, disconnect the X1 harness connector at the K69 transfer case control module.
    2. Test for less than 10 Ω in front axle actuator control circuit end to end.
      • If 10 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 10 Ω
    3. Test for greater than 10 Ω between the front axle actuator control circuit, terminal 2 and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
      • If 10 Ω or less, repair the short to ground condition in the circuit.
      • If greater than 10 Ω
    4. Test for greater than 1 Ω between front axle actuator control circuit, terminal 2 and all other terminals of the M26 front axle engagement actuator harness connector.
      • If 1 Ω or less, repair the short together condition in the affected circuits.
      • If greater than 1 Ω
    5. Ignition ON.
    6. Test for a less than 1.0 V between the front axle actuator control circuit, terminal 2, and a good ground such as the ground terminal of the EL-49742  harness, black terminal.
    • If B+ 
  10. Connect a test light between the Ignition 1 voltage circuit, terminal 1 and the front axle control circuit, terminal 2. Using the Front Axle Engagement Actuator control function of the scan tool, command the front axle to engage and disengage. When commanded to engage, the test light should illuminate. When commanded to disengage, the test light should turn OFF.
    • If the test light does NOT perform as described 

      Replace the K69 transfer case control module.

    • If the test light performs as described 
  11. The run/crank ignition 1 voltage circuit, the front axle switch signal circuit, the front axle control circuit, the ground circuit, and the K69 transfer case control module are OK.
RENDER: 1.0x

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