GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument panel cluster (IPC) detects high resistance with low engine oil temperature, and low resistance with high engine oil temperature. The instrument panel cluster monitors the oil temperature sensor signal circuit to determine engine oil temperature. The IPC measures the reference voltage change and displays the calculated value on the gage.

Conditions for Setting the DTC

    • The IPC detects that the oil temperature is less than -10°C (14°F)
    • The engine must be running for longer than 5 minutes for this DTC to set.

Action Taken When the DTC Sets

    • The IPC stores DTC B1543.
    • The IPC displays oil temperature on the gage as LOW.

Conditions for Clearing the DTC

    • The IPC detects that the oil temperature is above -10°C (14°F).
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • The code is cleared using on-board diagnostics.
    • The IPC receives a clear code command from the scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests the oil temperature normal operating range data using a scan tool.

Step

Action

Values

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the IPC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With a scan tool, observe the Oil Temp parameter in the IPC data 1 list.

Does the scan tool indicate that the Oil Temp parameter is within the specified range?

-10 to +190°C (14-374°F)

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Connect a 3-ampere fused jumper between the signal circuit of the engine oil temperature sensor and the low reference circuit of the engine oil temperature sensor.
  3. Turn the ignition ON , with the engine OFF.
  4. With a scan tool, observe the Oil Temp parameter.

Does the scan tool indicate that the Oil Temp parameter is greater than the specified value?

190°C (374°F)

Go to Step 6

Go to Step 4

4

Test the signal circuit of the engine oil temperature sensor for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 5

5

Test the low reference circuit of the engine oil temperature sensor for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector of the engine oil temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

7

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

Did you find and correct the condition?

--

Go to Step 10

Go to Step 9

8

Replace the engine oil temperature sensor. Refer to Engine Oil Temperature Gage Sensor Replacement Engine Mechanical.

Did you complete the replacement?

--

Go to Step 10

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9

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 10

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10

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC reset?

--

Go to Step 2

System OK