Checking Modules
- Generally, module failure rate is very low and therefore replacement modules usually do not resolve the root cause. Incorrect replacement of a module is often the result of inadequate testing.
- Understand the correct module function.
- Make sure programmable parameters are set correctly for the function in question (see the list in MODULE CONFIGURATION ).
- Resolve DTCs first - as directed by Diagnostic Routines.
- Test all inputs, both hard-wired and networked.
- Test outputs (see "CHECKING MODULE switching circuits" below).
- Check applicable TSBs for module software changes (flash programming).
- Checking module switching circuits.
- Using the scan tool module-output command function (e.g., IDS Output State Control) to activate components is a fast way to confirm an output is capable of being switched on by the module. Testing that reveals normal module-output function confirms the need to analyze the module inputs.
- Don't apply ground or power directly to module-switched components with jumper wires (unless directed by a Service Information procedure), as the component can be damaged by a direct connection to ground/power.