GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC is output when the instrument cluster detects the fuel sender gauge malfunction.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1500 Fuel Sender Open Detected

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

    • When 10 seconds have elapsed since the engine started and IG voltage is 10.5 volts or more.
    • A fuel sender gauge operation malfunction.

Action Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) illuminates the first time the diagnostic runs with the fault active.
    • The fuel gauge does not operate.

Conditions for Clearing the MIL/DTC

The DTC will clear when conditions for setting the DTC have been repaired.

Step

Action

Values

Yes

No

Schematic Reference: Instrument Cluster Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn the ignition to OFF.
  2. Disconnect the instrument cluster wiring harness connector E1.
  3. Measure between connector E1 terminals 10 and 25.

Is the resistance measured within specified value?

13.5 - 414.5 Ohms

Go to Step 9

Go to Step 3

3

  1. Disconnect the fuel gauge wiring harness connectors P10 and Q14.
  2. Measure between connector E1 terminal 25 and connector Q14 terminal 2.
  3. Measure between connector Q14 terminal 2 and body ground.
  4. Measure between connector Q14 terminal 3 and connector P10 terminal 1.
  5. Measure between connector P10 terminal 1 and body ground.
  6. Measure between connector P10 terminal 2 and connector E1 terminal 10.
  7. Measure between connector E1 terminal 10 and body ground.

Is the resistance measured within specified value?

Between E1 terminal 25 and Q14 terminal 2 = Below 1 Ohm

Between Q14 terminal 2 and body ground = 10 Kohms or higher

Between Q14 terminal 3 and P10 terminal 1 = Below 1 Ohm

Between P10 terminal 1 and body ground = 10 Kohms or higher

Between P10 terminal 2 and E1 terminal 10 = Below 1 Ohm

Between E1 terminal 10 and body ground = 10 Kohms or higher

Go to Step 4

Go to Step 8

4

  1. Remove the fuel suction pump and gauge.
  2. Measure the resistance between upper side connector terminal 2 and down side connector terminal 2.
  3. Measure the resistance between upper side connector terminal™3 and down side connector terminal 3.

Are the resistance values within the specified values?

Between upper side terminal 2 and under side terminal 2 = Below 1 Ohm

Between upper side terminal 3 and under side terminal 3 = Below 1 Ohm

Go to Step 5

Go to Step 10

5

Is vehicle FWD?

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Go to Step 6

Go to Step 7

6

Inspect fuel sender gauge assembly as follows:

  1. Remove the fuel sender gauge assembly.
  2. Check that the float moves freely from its upper to lower range.
  3. Measure the resistance between the main fuel sender gauge assembly connector terminals 1 and 2 with the float level in the upper, between upper and lower, and lower position.

Is the resistance measured within specified value?

Float level is upper = 13.5 - 16.5 Ohms

Float level is between upper and lower = 13.5 - 414.5 Ohms (gradually changes)

Float level is lower = 405.5 - 414.5 Ohms

Go to Step 9

Go to Step 11

7

Inspect fuel sender gauge assembly (main) and (sub) as follows:

  1. Remove the fuel sender gauge assembly.
  2. Check that the float moves freely from its upper to lower range.
  3. Measure the resistance between the main fuel sender gauge assembly connector terminals 1 and 2 with the float level in the upper, between upper and lower, and lower position.

Is the resistance measured within specified value?

For Main:

Float level is upper = 6.5 - 8.5 Ohms

Float level is between upper and lower = 6.5 - 245.7 Ohms (gradually changes)

Float level is lower = 240.7 - 247.7 Ohms

For Sub:

Float level is upper = 6.5 - 8.5 Ohms

Float level is between upper and lower = 6.5 - 168.8 Ohms (gradually changes)

Float level is lower = 164.8 - 168.8 Ohms

Go to Step 9

Go to Step 11

8

Repair or replace harness of the instrument cluster, fuel gauge assembly (main) or fuel gauge assembly (sub) connector. Refer to Wiring Repairs and Connector Repairs .

Did you complete the repair or replacement?

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Go to Step 12

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9

Replace the instrument cluster. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

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Go to Step 12

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Go to Step 8

10

Replace the fuel suction pump and gauge. Refer to Fuel Pump and Fuel Filter Assembly Replacement for the 1.8 L engine or Fuel Pump and Fuel Filter Assembly Replacement for the 2.4 L engine.

Did you complete the replacement?

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Go to Step 12

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11

Replace the fuel sender gauge. Refer to Fuel Sender Assembly Replacement for the 1.8 L engine or Fuel Sender Assembly Replacement for the 2.4 L engine.

Did you complete the replacement?

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Go to Step 12

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12

  1. Use the scan tool in order to clear the DTC.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

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Go to Step 2

System OK