Dodge Ram Truck 1500-2500-3500. Manual — part 1697

P0740-TORQ CON CLU, NO RPM DROP AT LOCKUP (GAS)

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AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

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P0740-TORQ CON CLU, NO RPM DROP AT LOCKUP (GAS) (CONTINUED)

For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE - SCHE-
MATICS AND DIAGRAMS)

For a complete wiring diagramRefer to Section 8W

Theory of Operation

The Torque Converter Clutch (TCC) solenoid is used to engage the TCC which improves fuel economy.

•

When Monitored:
Continuously with the ignition on.

•

Set Condition:
This DTC will set if the Torque Convertor Clutch (TCC) can not achieve the desired engine RPM drop when
the TCC Solenoid is near the maximum duty cycle after three consecutive test failures.

Possible Causes

TRANSMISSION FLUID LEVEL LOW OR CONTAMINATED

WORN OR DAMAGED REACTION SHAFT, INPUT SHAFT OR INPUT SHAFT SEALS

BLOCKED OR LEAK IN THE TCC HYDRAULIC CIRCUIT IN THE VALVE BODY

TORQUE CONVERTER CLUTCH SOLENOID

TORQUE CONVERTER

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

1.

CHECK IF THERE ANY ENGINE DTCS PRESENT

Ignition on, engine not running.

With the scan tool, read Engine DTCs.

Is the DTC P0743 also present?

Yes

>> Refer to the Transmission category and perform the appropriate symptom(s). (Refer to 21 - TRANS-

MISSION/TRANSAXLE/AUTOMATIC - 48RE - DIAGNOSIS AND TESTING)

No

>> Go To 2

2.

CHECK TRANSMISSION FLUID LEVEL

Check the transmission fluid level.

Is the Transmission fluid level low?

Yes

>> Inspect the transmission, cooler, and lines for leakage and repair as necessary. With the scan tool read

and record the Freeze Frame data for the reported DTC. Erase DTCs and test drive the vehicle to the
conditions in which the DTC originally set. Recheck for DTCs. If the DTC resets, follow the “No” path in
this test procedure and proceed to the next step.

If the DTC does not reset, test is complete, perform RE TRANSMISSION VERIFICATION TEST VER -
1 (GAS). (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCE-
DURE)

No

>> Go To 3

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P0740-TORQ CON CLU, NO RPM DROP AT LOCKUP (GAS) (CONTINUED)

3.

CHECK TRANSMISSION FLUID

Check the transmission fluid for contamination or a burnt condition.

Is the Transmission fluid contaminated or burnt?

Yes

>> Remove the valve body and inspect the components related to the Torque Converter Clutch. (Refer to

21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL) Check the valves
for sticking or binding in its bore, internal valve body leakage, or the TCC hydraulic circuits plugged with
debris. Repair as necessary. If no problems are found in the Valve Body, replace the Torque Convertor.
(Refer

to

21

-

TRANSMISSION/TRANSAXLE/AUTOMATIC

-

48RE/TORQUE

CONVERTER

-

REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Go To 4

4.

CHECK IF THE DTC IS CURRENT

With the scan tool, read Engine DTCs.

Record the Freeze Frame data for the reported DTC.

With the scan tool, erase DTCs.

Turn the ignition off to the lock position.

Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.

NOTE: It may be necessary to road test the vehicle to duplicate the original set conditions.
With the scan tool, read Engine DTCs.

Did the DTC reset?

Yes

>> Go To 5

No

>> Go To 9

5.

PERFORM TCC SYSTEM TEST

With the scan tool, perform the TCC System Test.

Follow the instructions on the screen.

Did the engine stall?

Yes

>> Go To 6

No

>> Go To 7

6.

PERFORM GOV AND 3-4 SHIFT VALVE SYSTEM TEST

With the scan tool, perform the Gov and 3-4 Shift Valve System Test.

Follow the instructions on the screen.

Did the engine stall?

Yes

>> Go To 8

No

>> Go To 7

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P0740-TORQ CON CLU, NO RPM DROP AT LOCKUP (GAS) (CONTINUED)

7.

CHECK THE COOLER OUT PRESSURE

Turn the ignition off to the lock position.

Connect a pressure gauge to the transmission cooler out port with a “T” connector. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - DIAGNOSIS AND TESTING)

Start the engine, with the scan tool, perform the TCC System Test.

Did the cooler out pressure on the gauge increase when the TCC was actuated?

Yes

>> Remove the transmission oil pump and inspect the reaction shaft, input shaft and input shaft seals for

damage or wear and repair or replace as necessary. Replace the Torque Convertor.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Remove the Valve Body and inspect for an internal blockage or an internal leak in the TCC hydraulic

circuit. Repair as necessary. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/VALVE
BODY - REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (GAS). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

8.

TCC SOLENOID

Turn the ignition off to the lock position.

Replace the TCC Solenoid per the Service Information (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC -
48RE/GOVERNOR PRESSURE SENSOR - REMOVAL).

With the scan tool, perform the Gov and 3-4 Shift Valve System Test.

Follow the instructions on the screen.

Did the engine stall?

Yes

>> Repair internal transmission as necessary. Check for blocked or cross linked passages in the Valve

Body. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE/VALVE BODY - REMOVAL)

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Test Complete.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

9.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary set this DTC are not present at this time.

Use the Freeze Frame Data to help duplicate the conditions that set the DTC. Pay particular attention to the DTC
set conditions, such as, VSS, MAP, ECT, and Load.

Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Refer to any technical service bulletins that may apply.

Were there any problems found?

Yes

>> Repair as necessary.

Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 48RE - STANDARD PROCEDURE)

No

>> Test Complete.

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