Diagnostic Procedures

1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 FSECTION Diagnostic Procedures
WARNING: This page is about a different car, the 1998 GMC Savana, 1998 Chevrolet Chevy Van, and 1998 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECKΒ . Retrieve and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. After performing OBD system check, go to next step.
  2. Turn ignition on, with engine off. Using scan tool, compare fuel level on scan tool and vehicle fuel gauge. If fuel levels are about the same, go to next step. If fuel level on scan tool and fuel gauge is not the same, go to step 4).
  3. DTC is intermittent. Check for additional DTCs set. Diagnose affected DTCs. If no additional DTCs are set, see DIAGNOSTIC AIDS.
  4. Turn ignition off. Disconnect fuel level sending unit harness connector at fuel tank. Turn ignition on, engine off. Using DVOM, check voltage between ground and fuel level signal circuit at harness connector. If voltage reading is about 5 volts, go to step 6). If voltage reading is not about 5 volts, go to next step.
  5. Repair open or short to ground in fuel level sender signal circuit. After repairs, go to step 9).
  6. Check fuel level sending unit for corrosion, faulty terminal connector, proper alignment to tank or for restricted/binding fuel level float. If problem is found, go to next step. If no problem is found, go to step 8).
  7. Repair as necessary. After repairs, go to step 9).
  8. Replace fuel level sending unit. After replacing sender, go to next step.
  9. Using scan tool, record fuel level sensor voltage. Change fuel level in vehicle. If sensor voltage changes, go to next step. If sensor voltage does not change, repeat step 2).
  10. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.