LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2018 >> Escalade ESV Platinum, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Transfer Case - Mp 3023/3024 (NQH)) >> Diagnostic Information And Procedures >> DTC C0364 Or C0379: Front Axle System/Front Axle Switch Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, disconnect the harness connector at the M26 front axle engagement actuator.
  2. Ignition ON, engine OFF.
  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.
    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 BL probes J 35616-64B.
    • If less than B+ (+0.0/-1.0 V) 
    1. Ignition OFF, remove the F76UA 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.
    • Go to next step: 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.
    • Go to next step: 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.
    • Go to next step: If B+ 
  8. Four wheel drive wheel lock indicator circuit OK.
  9. Test for 2.8 to 4.8 V between the test points: Front Axle Actuator Control & Chassis Ground
    • If less than 2.8 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
    • If greater than 4.8 V 
    1. Ignition OFF, disconnect the X1 harness connector at the K69 transfer case control module.
    2. Test for greater than 5Ω between front axle actuator control circuit, terminal 2 and all other terminals of the M26 front axle engagement actuator harness connector.
      • If 5Ω or less, repair the short together condition in the affected circuits.
      • If greater than 5Ω
    3. Ignition ON.
    4. 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.
    • Go to next step: If between 2.8 and 4.8 V 
  10. 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.
scientia non olet · About LEMON Manuals