GM Service Manual Online
For 1990-2009 cars only

Object Number: 541856  Size: MF
Power and Grounding Components
Instrument Cluster: Analog Schematics

Circuit Description

The Instrument Panel Cluster (IPC) receives oil temperature information from the oil temperature sensor. The oil temperature sensor is a thermistor type sensor, which will produce high resistance with low engine oil temperature, while low resistance with high engine oil temperature. The IPC supplies a 5 volt reference signal to the oil temperature sensor. When the engine oil is cold, the sensor resistance will decrease, and the IPC reference voltage level will drop. The IPC measures the reference voltage change and displays the calculated value on the gauge.

Conditions for Setting the DTC

    • The IPC detects oil temperature less than -10°C (14°F)
    • The IPC detects a high voltage level (an open) in oil temperature sensor circuit.
    • The engine must be running for longer than 5 minutes for this DTC to set.

Action Taken When the DTC Sets

    • Stores a DTC B1543 in the IPC memory.
    • The IPC displays oil temperature as LOW.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

    • The IPC detects oil temperature above -10°C (14°F)
    • The IPC no longer detects a high voltage level (an open) in oil temperature sensor circuit.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use the IPC clear DTC feature.
    • Use a scan tool.

Diagnostic Aids

    • The following conditions may cause an intermittent malfunction to occur:
       - An intermittent open or high resistance in the oil temperature sensor circuit.
       - An internal open in the oil temperature sensor.
    • If there is an open in the oil temperature sensor or related wiring, the IPC will display LOW for oil temperature.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

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

  2. Tests the oil temperature data with the oil temperature sensor disconnected. The scan tool will display Oil Temp data less than 10°C (14°F) with the oil temperature sensor disconnected.

  3. Tests the oil temperature data with a jumper between the oil temperature sensor signal and ground circuit. The scan tool will display Oil Temp data over 190°C (374°F) with the oil temperature sensor jumpered.

DTC B1543 -- Oil Temperature Circuit Open

Step

Action

Value(s)

Yes

No

1

Did you perform the IPC Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

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

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

-10°C (14°F)-190°C (374°F)

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the oil temp.
  3. Turn ON the ignition, 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 less than the specified value?

-10°C (14°F)

Go to Step 4

Go to Step 5

4

  1. Turn OFF the ignition.
  2. Connect a 3 amp fused jumper wire between the signal circuit of the oil temperature sensor and the ground circuit of the oil temperature sensor.
  3. Turn ON the ignition, 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 8

Go to Step 6

5

Test the signal circuit of the oil temperature 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 9

6

Test the signal circuit of the oil temperature sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs

Did you find and correct the condition?

--

Go to Step 12

Go to Step 7

7

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

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness connector of the oil temperature sensor. 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

9

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

10

Replace the oil temperature sensor.

Did you complete the replacement?

--

Go to Step 12

--

11

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

--

Go to Step 12

--

12

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

Does the DTC reset?

--

Go to Step 2

System OK