GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Corvette 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 DTC P1115

Circuit Description

The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.

Conditions for Running the DTC

Engine run time is more than 60 seconds.

Conditions for Setting the DTC

The PCM detects an ECT sensor temperature that is less than -35°C (-31°F).

The intermittent condition which exists for 1 second during a 20 second time period

Action Taken When the DTC Sets
    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC
    • A current DTC Last Test Failed clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Diagnostic Aids
    • An ECT sensor or a PCM which has any of the following intermittent conditions is unlikely:
       - A short
       -  An open
       - A skewed sensor
    • An intermittent open or a short to voltage in the signal circuit of the ECT sensor, may result in a DTC P1115. If there is a high ECT voltage reading, additional circuit voltage codes of the sensor may be set. Refer to any non-intermittent DTCs that are set.
    • In order to evaluate the possibility of a skewed sensor, test the coolant sensor at various temperature levels. A skewed sensor may result in driveability concerns. Refer to Temperature Versus Resistance .

Test Description

The number below refers to the step number on the diagnostic table.

  1. If the DTC does not set, and there are not any driveability concerns which are associated with this DTC, the system is OK.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Connect a scan tool.
  2. Turn ON the ignition.
  3. Start the engine.

Does the scan tool indicate that DTC P0118 also failed?

Go to DTC P0118

Go to Step 3

3
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool observe the ECT, and move the sensor connector, and the PCM connector.

Does the scan tool indicate an abrupt change in value?

Go to Step 6

Go to Step 4

4
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the ECT and move the wiring harness at the sensor, and at the PCM.

Does the scan tool indicate an abrupt change in value?

Go to Step 7

Go to Step 5

5

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. In order to operate the vehicle under the conditions which set the DTC, use the following information:
    5. • The data in the Freeze Frame/Failure Records
    • The parameters listed in the Conditions for Running in the DTC

Does the DTC set ?

Go to Diagnostic Aids

Go to Step 8

6

Repair the connector or the terminal as necessary. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you complete the repair?

 

--

7

Repair the harness or the wiring as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

--

8
  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run, and pass?

Go to Step 9

Go to Step 2

9

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK