Circuit/System Testing

2006 Chevrolet Suburban C2500, 6.0 USECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at X124.
  2. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal E at the female side of the connector and ground.
    • If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PTO module.
    • If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PTO module.
  3. Ignition ON, test for 0 volts between the 5-volt reference circuit terminal E at the male side of the connector and ground.
    • If greater than the specified value, test the 5-volt reference circuit between X124 and the upfitted remote PTO switch assembly for a short to voltage. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
  4. Ignition OFF, test for infinite resistance between the 5-volt reference circuit terminal E at the male side of the connector and ground.
    • If less than the specified value, test the 5-volt reference circuit for a short to ground. If the circuit tests normal, test or replace the upfitted remote PTO switch assembly.
  5. If all circuits test normal, replace the PTO module.
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When to See a Mechanic

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

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