Diagnostic Procedure
- Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After performing Diagnostic System Check - Engine Controls, go to next step.
- Start and idle engine. Observe message center in instrument cluster. Does message center indicate water-in-fuel? If yes, go to next step. If no, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - TRUCKS article.
- Perform Water-In-Fuel Draining Procedure. See WATER-IN-FUEL DRAINING PROCEDURE (6.6L) . After performing procedure, go to next step.
- Start and idle engine. Observe message center in instrument cluster. Does message center indicate water-in-fuel? If yes, go to next step. If no, go to step 10.
- Disconnect water-in-fuel sensor. Does scan tool display Water-In-Fuel parameter is OFF? If yes, go to step 8. If no, go to next step.
- Turn OFF the ignition. Disconnect ECM. Probe Water-In-Fuel Indicator Control circuit with a test light connected to battery voltage. Does test light illuminate? If yes, go to next step. If no, go to step 9.
- Repair short to ground in Water-In-Fuel Indicator Control circuit. After repairs, go to step 10.
- Replace water-in-fuel sensor. After repairs, go to step 10.
- Replace ECM. Perform ECM relearn procedures. See PROGRAMMING in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO article. After repairs, go to next step.
- Operate system in order to verify repair. Did you correct the condition? If yes, system is okay. If no, go to step 3.