SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2006CHEVY EXPRESS G2500, VAN CARGO, 6.6 2REPAIR AND DIAGNOSIS (SINGLE PAGE)ACCESSORIES & EQUIPMENTCOMMUNICATION DEVICESCOMPUTER/INTEGRATING SYSTEMSDIAGNOSTIC INFORMATION AND PROCEDURESDTC B1420DIAGNOSTIC AIDS
2006 Chevrolet Chevy Express G2500, Van Cargo, 6.6 2

Diagnostic Aids

2006 Chevrolet Chevy Express G2500, Van Cargo, 6.6 2SECTION Diagnostic Aids
  • The following may cause an intermittent:
    • A damaged terminal
    • A backed out terminal
    • A poor terminal tension
    • A chafed wire
    • A broken wire inside the insulation
  • When diagnosing an intermittent short or an open, manipulate the wire harness while watching the test equipment for changes.
DTC B1420

Step Action Values Yes No
Schematic Reference: Body Control System Schematics 
Connector End View Reference: Computer/Integrating Systems Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the battery voltage input parameter in the body control module (BCM) input data list.
Is the battery voltage input parameter in the specified range?		 9.0-16.0 V Go to Step 3  Go to Step 4 
3 Is DTC B1420 set as a current DTC? - Go to Step 7  Go to Diagnostic Aids
4
  1. Disconnect the BCM harness connectors.
  2. Measure the voltage between the battery positive voltage circuit at the BCM harness connector and a good ground. Refer to Circuit Testing in Wiring Systems.
Is the measured value in the specified range?		 9.0-16.0 V Go to Step 6  Go to Step 5 
5 Test the battery positive voltage circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 9  Go to Battery Inspection/Test (Non-HP2) in Engine Electrical
6 Test the all of ground circuits of the BCM for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 9  Go to Step 7 
7 Inspect for poor connections at the module harness connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 9  Go to Step 8 
8 Replace the BCM. Refer to Control Module References  in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 9  -
9 Operate the system in order to verify the repair.
Did you find and correct the condition?		 - System OK Go to Step 2 
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.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

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

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