GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Express - AWD 🢒 Driver Information and Entertainment 🢒 Displays and Gages 🢒 Water-in-Fuel Lamp Always On

Diagnostic Aids
    • The water in fuel sensor illuminates the Water in Fuel message when there is water in the fuel system. Perform the Water in Fuel Draining procedure before performing the following test steps to accurately determine if a malfunction exists. Refer to Water-in-Fuel Draining .
    • For intermittent diagnosis, refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics , Engine Controls Schematics for the 6.6L (LMM) engine, or Engine Controls Schematics for the 6.6L (LBZ and LLY) engine

Connector End View Reference: Engine Control Module Connector End Views for the 6.6L (LMM) engine, or Engine Control Module Connector End Views for the 6.6L (LBZ and LLY) engine

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Does the Water In Fuel indicator remain illuminated in the instrument panel cluster (IPC) after the displays test?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3
  1. Turn OFF the ignition.
  2. Disconnect the water in fuel sensor.
  3. Turn ON the ignition, with the engine OFF.

Does the Water In Fuel indicator illuminate in the IPC?

Go to Step 4

Go to Step 6

4

Test the signal circuit of the water in fuel sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 5

5
  1. Install a scan tool.
  2. Turn OFF the ignition.
  3. Disconnect the water in fuel sensor.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the Water In Fuel Sensor parameter in the powertrain control module (PCM) Engine Data 1 data list.

Does the Water In Fuel Sensor parameter display No Water?

Go to Step 8

Go to Step 7

6

Inspect for poor connections at the harness connector of the water in fuel switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

7

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 10

8

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

9

Replace the fuel strainer bowl. Refer to:

    •  Fuel Strainer Bowl Replacement for the 6.6L (LMM) engine
    •  Fuel Strainer Bowl Replacement for the 6.6L (LBZ and LLY) engine

Did you complete the replacement?

Go to Step 12

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10

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

11

Replace the IPC. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2