GM Service Manual Online
For 1990-2009 cars only

Object Number: 715911  Size: SF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

Continuous power is required for the keep-alive memory inside the transmission control module (TCM). A fused Battery Voltage circuit supplies voltage on terminal 26 of the TCM.

When the TCM detects that voltage has been interrupted on the Battery Voltage circuit, then DTC P1760 will set. DTC P1760 is a type C DTC.

Condition for Running the DTC

The ignition is ON.

Condition for Setting the DTC

The TCM detects a voltage interrupt.

Action Taken When the DTC Sets

    • The TCM flashes the sport mode lamp.
    • The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM records this information as Failure Records.
    • The TCM stores DTC P1760 in TCM history.
    • The TCM restores the RAM values from the EEPROM memory.

Conditions for Clearing the DTC

    • A history DTC clears after forty consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission related diagnostic.
    • A scan tool can clear the DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
    • The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids

DTC P1760 may set due to temporary conditions, such as a dead battery. If the power was interrupted for any reason, this DTC will set. Check the vehicle's repair history for repairs that may have interrupted the power.

Test Description

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

  1. A short to ground in circuit A828 would cause the Clamp 30 fuse to open.

  2. Replace the TCM only after all other test procedures have been completed.

Step

Action

Value(s)

Yes

No

1

Did you perform Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission ?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission

2

  1. Install the Scan Tool .
  2. Turn ON the ignition with the engine OFF.

Is the Scan Tool able to communicate with the TCM?

--

Intermittent Conditions in Engine Controls

Go to Step 3

3

Caution: When you are performing service on or near the SIR components or the SIR wiring, you must disable the SIR system. Refer to Disabling the SIR System. Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.

  1. Turn OFF the ignition.
  2. Disconnect the TCM.
  3. Connect the J 35616-200 test light to ground.
  4. Probe terminal 26 of the TCM harness connector.

Does the test light illuminate?

--

Go to Step 4

Go to Step 6

4

Inspect the TCM and the TCM connector for the following:

    • TCM and connector are properly aligned and the connector lock is fully engaged.
    • Backed-out connector terminals.
    • Bent or damaged TCM terminals.

Did you find the condition?

--

Go to Step 9

Go to Step 5

5

Replace the TCM.

Refer to Transmission Control Module Replacement .

Is the action complete?

--

Go to Step 10

--

6

Inspect the #5 A/T fuse.

Did you find an open fuse?

--

Go to Step 7

Go to Step 8

7

Inspect the Battery Voltage circuit (CKT A828) for a short to ground.

Refer to Testing for Short to Ground in Wiring Systems.

Did you find the condition?

--

Go to Step 9

--

8

Inspect the Battery Voltage circuit (CKT A828) for an open.

Did you find the condition?

--

Go to Step 9

--

9

Repair the circuit as necessary.

Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 10

--

10

Turn ON the ignition with the engine OFF.

Can the Scan Tool communicate with the TCM?

--

Go to Step 11

Go to Step 1

11

  1. Turn ON the ignition with the engine OFF.
  2. Select DTC.
  3. Select Clear Info.

Did the TCM DTC clear?

--

System OK

--