DTC P0740 TCC Enable Solenoid Circuit Electrical. Chevrolet Tahoe Limited 2000

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Tahoe Limited 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L60-E 🢒 DTC P0740 TCC Enable Solenoid Circuit Electrical

Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The torque converter clutch (TCC) solenoid valve is an electrical device that is used with the torque converter clutch pulse width modulation (TCC PWM) solenoid valve in order to control TCC apply and release. The TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. The TCC solenoid valve receives ignition voltage through circuit 1020. The vehicle control module (VCM) controls the solenoid by providing the ground path on circuit 422. The VCM monitors the throttle position (TP) voltage, the vehicle speed, and other inputs in order to determine when to energize the TCC solenoid valve.

When the VCM detects a continuous open, short to ground, or short to power in the TCC solenoid valve circuit, then DTC P0740 sets. DTC P0740 is a type A DTC.

Conditions for Running the DTC

•	The system voltage is 10-19 volts.

•	The engine speed is greater than 450 RPM for 5 seconds.

•	The engine is not in fuel cutoff.

Conditions for Setting the DTC

DTC P0740 sets if one of the following conditions occurs for 5 seconds:

Condition 1

The VCM commands the solenoid ON and the voltage feedback remains high (B+).

Condition 2

The VCM commands the solenoid OFF and the voltage feedback remains low (0 volt).

Action Taken When the DTC Sets

•	The VCM illuminates the malfunction indicator lamp (MIL).

•	The VCM inhibits TCC engagement.

•	The VCM inhibits 4th gear if the transmission is in hot mode.

•	The VCM freezes shift adapts from being updated.

•	The VCM records the operating conditions when the Conditions for Setting the DTC are met. The VCM stores this information as Freeze Frame and Failure Records.

•	The VCM stores DTC P0740 in VCM history.

Conditions for Clearing the MIL/DTC

•	The VCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.

•	A scan tool can clear the MIL/DTC.

•	The VCM clears the DTC from VCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

•	The VCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the VCM.

Diagnostic Aids

•	Inspect the wiring at the VCM, the transmission connector and all other circuit connecting points for the following conditions:

-	A backed out terminal

-	A damaged terminal

-	Reduced terminal tension

-	A chafed wire

-	A broken wire inside the insulation

-	Moisture intrusion

Corrosion

•	When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

•	With the TCC engaged, the TCC slip speed should be -20 to +50 RPM.

Test Description

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

This step tests for voltage to the solenoid.

This step tests the ability of the VCM and wiring to control the ground circuit.

This step tests the resistance of the TCC solenoid valve and the automatic transmission (AT) wiring harness assembly.

DTC P0740 TCC Enable Solenoid Circuit Electrical

Step

Action

Value(s)

Yes

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

Install a Scan Tool .
With the engine OFF, turn the ignition switch to the RUN position.

Important: Before clearing the DTC, use the Scan Tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the VCM.

Record the DTC Freeze Frame and Failure Records.
Clear the DTC.

Are any of the following DTCs also set?

•

P0753

•

P0758

•

P0785

•

P1860

Go to Step 3

Go to Step 4

Inspect the TRANS fuse for an open.

Refer to General Electrical Diagnosis in Wiring Systems.

Is the fuse open?

Go to Step 9

Go to Step 4

Turn the ignition switch OFF.
Disconnect the AT inline 20-way connector (additional DTCs may set).
Install the J 44152 jumper harness (20 pins) on the engine side of the AT inline 20-way connector.
With the engine OFF, turn the ignition switch to the RUN position.
Using the J 35616-A connector test adapter kit, connect a test lamp from cavity E of the J 44152 to ground.

Refer to Automatic Transmission Inline Harness Connector End View .

Is the test lamp ON?

Go to Step 5

Go to Step 12

Install the test lamp from cavity E to cavity T of the J 44152 .

Refer to Automatic Transmission Inline Harness Connector End View .

Using the transmission output control function on the Scan Tool , command the TCC solenoid valve ON and OFF three times.

Does the test lamp turn ON when the TCC solenoid valve is commanded ON, and OFF when commanded OFF?

Go to Step 7

Go to Step 6

Is the test lamp always ON?

Go to Step 13

Go to Step 14

Install the J 44152 on the transmission side of the AT inline 20-way connector.
Using the J 39200 digital multimeter (DMM) and the J 35616-A connector test adapter kit, measure the resistance between terminals T and E.

Refer to Automatic Transmission Inline Harness Connector End View .

Is the resistance within the specified range?

21-33 ohms

Go to Step 8

Go to Step 15

Measure the resistance from terminal E of the J 44152 to ground.
Measure the resistance from terminal T of the J 44152 to ground.

Are both readings greater than the specified value?

250 K ohms

Go to Diagnostic Aids

Go to Step 15

Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution.