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Post #1

hey guys,

I had a p 0740 code come up last week. I reset the comp and the check engine light goes off for a while. Then the check engine light comes back on after about 30 minutes of driving.

I have seen other threads here that describe the problem but no one that i can find actually tells you what worked to fix the problem. I can rebuild an engine but have never had to deal with an auto transmission.

Torque converter clutch solenoid seems to be mostly talked about but none of the thread starters seem to write in to say if the solenoid was actually the problem. ( I hate how many threads die!!!:)

I'm fairly comfy pulling the filter off and getting to the solenoid and swapping it but...... don't want to if it is not the problem.


Can someone please tell me what worked for people who have had this code come up???? thanks in advance.


2002 Dodge Ram 1500 SLT 360

 

DT links are not allowed but sounds like the solenoid or TC.

 

Ok so I guess i should try and change the solenoids first and if that doesnt work do the TC. Correct...?

 

P0740-TORQ CON CLU, NO RPM DROP

AT LOCKUP (GAS

This is from the FSM,

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

For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 48RE - SCHEMATICS
AND DIAGRAMS)
For a complete wiring diagram

Refer to Section 8W

Theory of Operation

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

²

When Monitored:

Continuously with the ignition on.

²

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 - TRANSMISSION/
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 - TRANSMISSION/
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 PROCEDURE)

No

>> Go To 3

DR/DH

AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS 21 - 721

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

21 - 722 AUTOMATIC TRANSMISSION - 48RE - GAS - ELECTRICAL DIAGNOSTICS

DR/DH

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.

 

I am currently at the dealer now to have the code cleared. When the engine light came on I checked the EVIC and went through all the gauge readings and tyranny temp was at 174. Weird, I was only hauling a 14 ft trailer with 2 snowmobiles on it with a 15 mph tail wind.

 

Jeepdude,
I know how you feel about threads dying. I have been trying to fix my P0740 error also. I am going to post this in my original post but I thought I would let some of you know the solenoids didnt work for me. I am having slipping problems where at it's worst I have no reverse, 1st, 2nd, 3rd or OD. OD light has come on by itself once. Also the truck drives like a champ for 10-20 minutes then it goes south. So for the record I have replaced both governor components, OD-TCC colenoid w\harness, Fluid and filter. My next project will be the front&rear band adjustments, fluid pressure adjustments and the tranny speed sensor.
If that dont work Im going to replace the torque convertor.