GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 Wave 🢒 DTC 🢒 DTC P0785 or P1710

DTC P0785 or P1710 Non European or N. American Emissions

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P0785 3-2 Shift Solenoid (SS) Control Circuit
    • DTC P1710 Timing Solenoid Circuit

Conditions for Setting the DTC
    • The transmission control module (TCM) detects that the ON signal of the timing solenoid monitor during 0.5 second when the timing solenoid driver outputs the OFF signal. The timing solenoid circuit is open or short to battery.
    • The TCM detects that the OFF signal of the timing solenoid monitor during 0.1 second when the timing solenoid driver outputs the ON signal. The timing solenoid circuit is short to battery.
    • The above detection 3 times at shifting continuously.

Action Taken When the DTC Sets
    • The TCM will request the illumination of the hold lamp and store the DTC when the TCM detects a failure on the first ignition cycle.
    • After failure decision: emergency mode

Conditions for Clearing the DTC
    • The TCM turns off the hold lamp when no further failures are detected on the next ignition cycle.
    • 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.
    • The TCM detects the ON signal of the timing solenoid monitor during 100 ms when the timing solenoid driver outputs the ON signal and the TCM detects the OFF signal of the timing solenoid monitor during 160 ms when the timing solenoid driver outputs the OFF signal.

Cause of Failure
    • The wiring harness or the connector between the timing solenoid and the TCM
    • The timing solenoid
    • 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 Store Freeze Frame/Failure Records from the DTC Information menu.
  5. Store Freeze Frame/Failure Records.
  6. Select Clear DTC Information from the DTC Information menu.
  7. Clear the DTC information.
  8. Perform one vehicle drive cycle.

Is the hold lamp ON?

--

Go to Step 3

Go to Step 5

3
  1. Select Request DTC by Status from the DTC Information menu.
  2. Request DTC by Status.

Is DTC P0785/P1710 displayed?

--

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Measure the resistance between the vehicle harness and the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .
  3. Disconnect the transmission control module (TCM) connector and measure the resistance between the terminal A24 and A23.

Is the measurement within the specified values?

20°C (68°F)

11-16 Ω

Go to Step 6

Go to Step 7

5

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

Did you complete the repair?

--

System OK

--

6
  1. Inspect for damage between the vehicle wiring harness connector and the TCM.
  2. Inspect the connector. Refer to Wiring Harness and Connector Inspection Diagnosis .
  3. Inspect the connection condition between the connectors.

Is the connection condition OK?

--

Go to Step 8

Go to Step 5

7
  1. Inspect for damage between the vehicle harness and the timing solenoid.
  2. Disconnect the transaxle harness connector and measure the resistance between the timing solenoid connector terminal 2 and ground.

Is the measurement within the specified values?

20°C (68°F)

11-16 Ω

Go to Step 9

Go to Step 10

8
  1. Replace the TCM. Refer to Transmission Control Module Replacement .
  2. Perform the reproducing test under user condition after confirming no DTC.

Is DTC displayed?

--

Go to Step 2

System OK

9
  1. Inspect for damage of the vehicle wiring harness or between the connectors.
  2. Test the continuity and short circuit for the vehicle wiring harness and inspect the connection condition between connectors. Refer to Wiring Harness and Connector Inspection Diagnosis .

Is the condition OK?

--

Go to Step 5

Go to Step 13

10
  1. Inspect for damage of the transaxle harness between the connectors of the timing solenoid.
  2. Inspect the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .

Is the condition found?

--

Go to Step 12

Go to Step 11

11
  1. Inspect for damage of the transaxle harness.
  2. Test the continuity and short circuit the transaxle harness and inspect the connection condition between connectors. Refer to Wiring Harness and Connector Inspection Diagnosis .

Is the condition OK?

--

Go to Step 5

Go to Step 14

12

Replace the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .

Did you complete the replacement?

--

System OK

--

13

Repair or replace the vehicle harness.

Did you complete the repair?

--

System OK

--

14

Replace the transaxle harness.

Did you complete the replacement?

--

System OK

--

DTC P0785 or P1710 European and N. American Emissions

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P0785 3-2 Shift Solenoid (SS) Control Circuit
    • DTC P1710 Timing Solenoid Circuit

Conditions for Setting the DTC
    • The transmission control module (TCM) detects that the ON signal of the timing solenoid (ST) monitor during 0.5 second when the timing solenoid driver outputs the OFF signal. The timing solenoid circuit is open or short to battery.
    • The TCM detects that the OFF signal of the timing solenoid monitor during 0.1 second when the timing solenoid driver outputs the ON signal. The timing solenoid circuit is short to battery.
    • The above detection 3 times at shifting continuously.

Action Taken When the DTC Sets
    • The TCM will request the illumination of the malfunction indicator lamp (MIL) and store the DTC when the TCM detects a failure on the first ignition cycle.
    • After failure decision: emergency mode

Conditions for Clearing the DTC
    • The TCM turns off the MIL when no further failures are detected on the next ignition cycle.
    • 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.
    • The TCM detects the ON signal of the timing solenoid monitor during 100 ms when the timing solenoid driver outputs the ON signal and the TCM detects the OFF signal of the timing solenoid monitor during 160 ms when the timing solenoid driver outputs the OFF signal.

Cause of Failure
    • The wiring harness or the connector between the timing solenoid and the TCM
    • The timing solenoid
    • 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 Store Freeze Frame/Failure Records from the DTC Information menu.
  5. Store Freeze Frame/Failure Records.
  6. Select Clear DTC Information from the DTC Information menu.
  7. Clear the DTC information.
  8. Perform one vehicle drive cycle.

Is the malfunction indicator lamp (MIL) ON?

--

Go to Step 3

Go to Step 5

3
  1. Select Request DTC by Status from the DTC Information menu.
  2. Request DTC by Status.

Is DTC P0785/P1710 displayed?

--

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Measure the resistance between the vehicle harness and the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .
  3. Disconnect the transmission control module (TCM) connector and measure the resistance between the terminal A24 and A23.

Is the measurement within the specified values?

20°C (68°F)

11-16 Ω

Go to Step 6

Go to Step 7

5

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

Did you complete the repair?

--

System OK

--

6
  1. Inspect for damage between the vehicle wiring harness connector and the TCM.
  2. Inspect the connector. Refer to Wiring Harness and Connector Inspection Diagnosis .
  3. Inspect the connection condition between the connectors.

Is the connection condition OK?

--

Go to Step 8

Go to Step 5

7
  1. Inspect for damage between the vehicle harness and the timing solenoid.
  2. Disconnect the transaxle harness connector and measure the resistance between the timing solenoid connector terminal 2 and ground.

Is the measurement within the specified values?

20°C (68°F)

11-16 Ω

Go to Step 9

Go to Step 10

8
  1. Replace the TCM. Refer to Transmission Control Module Replacement .
  2. Perform the reproducing test under user condition after confirming no DTC.

Is DTC displayed?

--

Go to Step 2

System OK

9
  1. Inspect for damage of the vehicle wiring harness or between the connectors.
  2. Test the continuity and short circuit for the vehicle wiring harness and inspect the connection condition between connectors. Refer to Wiring Harness and Connector Inspection Diagnosis .

Is the condition OK?

--

Go to Step 5

Go to Step 13

10
  1. Inspect for damage of the transaxle harness between connectors of timing solenoid.
  2. Inspect the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .

Is the condition found?

--

Go to Step 12

Go to Step 11

11
  1. Inspect for damage of the transaxle harness.
  2. Test the continuity and short circuit the transaxle harness and inspect the connection condition between connectors. Refer to Wiring Harness and Connector Inspection Diagnosis .

Is the condition OK?

--

Go to Step 5

Go to Step 14

12

Replace the timing solenoid. Refer to 1, 2 Shift Solenoid, Timing Solenoid, and Lock-Up Solenoid Inspection .

Did you complete the replacement?

--

System OK

--

13

Repair or replace the vehicle harness.

Did you complete the repair?

--

System OK

--

14

Replace the transaxle harness.

Did you complete the replacement?

--

System OK

--