P0758

Description:

Description:

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The shift solenoids are in the valve body in the main case of the transmission. The Transmission Control Module (TCM) selects the required gear by controlling the appropriate solenoid. The accompanying table (see image) indicates the solenoid control combinations which result in the 4 forward drive ranges:

Shift Solenoid Control Combinations:

The Shift Solenoids are supplied power via the Transmission Power Relay (internal to the TCM). The TCM controls the solenoids by grounding the appropriate control circuit via an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which the TCM monitors. When the TCM commands a component on, the voltage of the control circuit should be low (near 0 volts). When the TCM commands the control circuit to a component off, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what you expect, a DTC will set.

CONDITIONS FOR RUNNING THE DTC

Tests continuously

CONDITIONS FOR SETTING THE DTC

A short to ground, open circuit, or short to battery voltage detected on the control circuit.

ACTION TAKEN WHEN THE DTC SETS

^ The TCM illuminates the Service Transmission Lamp (STL) and sends a Malfunction Indicator Lamp (MIL) Request to the ECM on the second consecutive drive trip that the diagnostic runs and fails. The ECM then illuminates the MIL.

^ The ECM records the operating conditions in the Freeze Frame at the time of the MIL Request from the TCM.

^ The transmission operates in the Default Mode.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The TCM turns off the STL as soon as the fault is no longer present.

^ The ECM turns off the MIL after three consecutive drive trips during which the TCM sends no MIL Request.

^ A History DTC clears after forty consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission related diagnostic.

^ The scan tool clears the MIL/DTC.

DIAGNOSTIC AIDS

Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the TCM harness connector or a component harness connector. Using this kit will prevent damage to the harness connector terminals.

Check for the following conditions:

^ Poor connections at the TCM or at the component. Inspect the harness connectors for any backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Refer to Overall Vehicle Information / Diagrams / Diagnostic Aids for Checking Terminal Contact procedure.

6 Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving any related connectors and any wiring harnesses. A change in the display may help to locate the fault.

TEST DESCRIPTION

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

2. Allows the TCM to determine if the fault is present now.

3. Listen for an audible click when the solenoid operates. Ground the circuit repeatedly if necessary.

4. This check can detect a partially shorted coil which would cause an excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When the coil becomes warm, the coil may open (amps drop to 0), or short (goes above 0.75 amp).

16. If the solenoid checks out OK, and no trouble is present with the connections at the TCM, check the wiring and the connections closely. If no trouble is found, the TCM may be the cause of the problem; however this would be an extremely unlikely failure.