how to troubleshoot GMC Sierra T1XX (2019-Present) hard starting issues?

Learn how to troubleshoot hard starting issues in GMC Sierra T1XX (2019-Present). Step-by-step diagnostic and repair instructions included.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shocks during repairs.

2. Battery Inspection and Replacement

• Sub-step 1: Remove the negative (-) battery terminal followed by the positive (+) terminal.
• Sub-step 2: Clean the battery terminals and cable ends using a wire brush.
• Sub-step 3: Test the battery with a multimeter; replace if voltage is below 12.4 volts.
• Sub-step 4: Reinstall the battery terminals, connecting the positive (+) terminal first, then negative (-).

3. Starter Motor Testing

• Sub-step 1: Locate the starter motor and inspect its wiring for damage.
• Sub-step 2: Use a multimeter to check for voltage at the starter solenoid while someone turns the ignition key to the start position.
• Sub-step 3: If no voltage is present, trace the wiring back to the ignition switch and relay.
• Sub-step 4: If voltage is present and the starter does not engage, replace the starter motor.

4. Fuel System Check

• Sub-step 1: Locate the fuel pump fuse in the fuse box and inspect it for continuity.
• Sub-step 2: If the fuse is intact, connect a fuel pressure gauge to the fuel rail.
• Sub-step 3: Turn the ignition to the "ON" position without starting the engine and check the fuel pressure reading; it should meet manufacturer specifications.
• Sub-step 4: If the pressure is low, replace the fuel pump.

5. Ignition System Inspection

• Sub-step 1: Remove the spark plugs and inspect them for wear and carbon buildup.
• Sub-step 2: Check the ignition coils for proper resistance with a multimeter; replace if out of specification.
• Sub-step 3: Reinstall the spark plugs and connect all ignition components securely.