GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Aveo 🢒 DTC 🢒 DTC P1701 or P1792

DTC P1701 or P1792 Non European or N. American Emissions

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P1701 Engine Coolant Temperature Sensor
    • DTC P1792 No Engine Coolant Temperature Signal

Conditions for Setting the DTC
    • The transmission control module (TCM) detects no engine coolant temperature (ECT) signal for 2 seconds continuously.
    • No DTC U2105
    • The TCM judges the ECT is 90°C (194°F) when lapsed 15 minutes from ignition ON.

Action Taken When the DTC Sets

The TCM will not request the illumination of the malfunction indicator lamp (MIL) or hold lamp, but will store the DTC when the TCM detects a failure on the first ignition cycle.

Conditions for Clearing the DTC
    • The scan tool can clear the DTC from the TCM history.
    • The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault.

Cause of Failure
    • The wiring harness or the connector between the engine control module (ECM) and the TCM
    • The ECM
    • The TCM

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2
  1. Turn OFF the ignition.
  2. Install the scan tool.
  3. With the engine OFF, turn the ignition switch to the ON position.
  4. Select Clear DTC Information from the DTC Information menu.
  5. Clear DTC Information.
  6. Perform one vehicle drive cycle.
  7. Select Request DTC by Status from the DTC Information menu.
  8. Request DTC by Status.

Is DTC P1701 or P1792 displayed?

--

Go to Step 3

Go to Step 8

3
  1. Turn OFF the ignition.
  2. Disconnect the transmission control module (TCM) wiring connector and the engine control module (ECM) wiring connector.
  3. Measure the resistance between terminal A17 of the TCM wiring connector and terminal K14, B14 or 88 of the ECM wiring connector.
  4. Measure the resistance between terminal A7 of the TCM wiring connector and terminal K15, B30 or 57of the ECM wiring connector.

Is the resistance within the specified value?

0 Ω

Go to Step 4

Go to Step 5

4
  1. Turn ON the ignition.
  2. Measure the voltage of terminal A17.
  3. Measure the voltage of terminal A7.

Is the voltage within the specified range?

11-14 V

Go to Step 5

Go to Step 6

5

Repair the malfunctioning terminals, as necessary.

Did you complete the repair?

--

System OK

--

6
  1. Replace the TCM. Refer to Transmission Control Module Replacement .
  2. Turn OFF the ignition.
  3. Turn ON the ignition.
  4. Inspect if DTC P1701 is set.

Is the DTC set?

--

Go to Step 7

Go to Step 9

7

Replace the ECM. Refer to the following:

    •  Engine Control Module Replacement for the 1.5L engine
    •  Engine Control Module Replacement for the 1.4L DOHC engine
    •  Engine Control Module Replacement for the 1.2L engine

Did you complete the replacement?

--

Go to Step 9

--

8

Repair the temporary connection of the connector. Refer to Wiring Harness and Connector Inspection Diagnosis .

Did you complete the repair?

--

System OK

--

9
  1. After the repair, use a scan tool Clear Info function and road test the vehicle.
  2. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 2

System OK

DTC P1701 or P1792 European and N. American Emissions

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P1701 Engine Coolant Temperature Sensor
    • DTC P1792 No Engine Coolant Temperature Signal

Conditions for Setting the DTC
    • The transmission control module (TCM) detects no engine coolant temperature (ECT) signal for 2 seconds continuously.
    • No DTC U2105
    • The TCM judges the ECT is 90°C (194°F) when lapsed 15 minutes from ignition ON.

Action Taken When the DTC Sets

The TCM will not request the illumination of the malfunction indicator lamp (MIL), but will store the DTC when the TCM detects a failure on the first ignition cycle.

Conditions for Clearing the DTC
    • The scan tool can clear the DTC from the TCM history.
    • The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault.

Cause of Failure
    • The wiring harness or the connector between the engine control module (ECM) and the TCM
    • The ECM
    • The TCM

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2
  1. Turn OFF the ignition.
  2. Install the scan tool.
  3. With the engine OFF, turn the ignition switch to the ON position.
  4. Select Clear DTC Information from the DTC Information menu.
  5. Clear the DTC information.
  6. Perform one vehicle drive cycle.
  7. Select Request DTC by Status from the DTC Information menu.
  8. Request DTC by Status.

Is DTC P1701 or P1792 displayed?

--

Go to Step 3

Go to Step 8

3
  1. Turn OFF the ignition.
  2. Disconnect the transmission control module (TCM) wiring connector and engine control module (ECM) wiring connector.
  3. Measure the resistance between terminal A17 of the TCM wiring connector and terminal K14, B14 or 88 of the ECM wiring connector.
  4. Measure the resistance between terminal A7 of the TCM wiring connector and terminal K15, B30 or 57 of the ECM wiring connector.

Is the resistance within the specified value?

0 ohms

Go to Step 4

Go to Step 5

4
  1. Turn ON the ignition.
  2. Measure the voltage of terminal A17.
  3. Measure the voltage of terminal A7.

Is the voltage within the specified range?

11-14 V

Go to Step 5

Go to Step 6

5

Repair the malfunctioning terminals, as necessary.

Did you complete the repair?

--

System OK

--

6
  1. Replace the TCM. Refer to Transmission Control Module Replacement .
  2. Turn OFF the ignition.
  3. Turn ON the ignition.
  4. inspect if DTC P1701 is set.

Is the DTC set?

--

Go to Step 7

Go to Step 9

7

Replace the ECM. Refer to the following:

    •  Engine Control Module Replacement for the 1.5L engine
    •  Engine Control Module Replacement for the 1.4L DOHC engine
    •  Engine Control Module Replacement for the 1.2L engine

Did you complete the replacement?

--

Go to Step 9

--

8

Repair the temporary connection of the connector. Refer to Wiring Harness and Connector Inspection Diagnosis .

Did you complete the repair?

--

System OK

--

9
  1. After the repair, use a scan tool Clear Info function and road test the vehicle.
  2. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 2

System OK