Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: If the flow rate number is not available in either control module, the numbers will need to be retrieved from each individual injector.

Fig 1: Fuel Injector Identification Numbers

Courtesy of GENERAL MOTORS CORP.

Callout	Component Name
1	Manufacturing Plant
2	IQA Number
3	Manufacturing Date
4	Injector Number
5	Serial Number

With a scan tool installed, enter the vehicle information and select the following options:
- Engine Control Module
- Module Setup
- Injector Flow Rate Programming
- Display ECM & GPCM Inj. Flow Rates
Record all flow rate numbers with the corresponding cylinders from the control modules.
- If any injectors are replaced, go to Reprogram Injector Flow Rates parameter and enter the flow rate number of the new injector to the corresponding cylinder. The flow rate numbers will automatically update both control modules.
- If the ECM was replaced, go to Copy GPCM Inj. Flow Rates to ECM parameter and reprogram the ECM. This will update the ECM with the GPCM flow rate numbers.
- If the GPCM was replaced or the flow rate numbers are not the same for both modules, go to Copy ECM Inj. Flow Rates to GPCM parameter and reprogram the GPCM. This will update the GPCM with the ECM flow rate numbers.
- If both control modules were replaced, go to Reprogram Injector Flow Rates parameter and enter the previously recorded flow rate numbers or the numbers retrieved from each individual injector, to the corresponding cylinders.