Circuit/System Testing

2011 GMC Savana Special 4.8 ASECTION Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, disconnect the harness connector at the B26 crankshaft position sensor.
  2. Ignition OFF and all vehicle systems OFF, it may take 2 minutes for all Vehicle systems to power down. Test for less than 5 Ξ© between the low reference circuit, terminal 2, and ground.
    • If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
  3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit, terminal 3 and ground.
    • If less than the specified range, test the 5 V reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 engine control module.
    • If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
  4. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 1 and ground.
    • If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 engine control module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
  5. Ignition OFF, connect a 3 A fused jumper wire to the signal circuit terminal 1 of the connector and ground.
  6. Ignition ON, momentarily touch the other end of the fused jumper wire to the ground repeatedly while monitoring the scan tool. The Crankshaft Position Active counter, should increment.
    • If the Crankshaft Position Active counter does not increment, replace the K20 engine control module.
  7. If all circuits test normal, test or replace the B26 crankshaft position sensor.
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.