The P0740 Code on Chevy Silverado: Meaning, Causes, and Fixes
Having trouble with shifting gears? Feeling stuck in the same old motion and cycles? For my fellow mates going through an existential crisis, I’m not talking about your life. I am talking about your Chevy Silverado, which might have a P0740 emergency.
On a Chevy Silverado, the P0740 code is a diagnostic trouble code (DTC) for “Torque Converter Clutch Circuit Malfunction”. It may denote a damaged torque converter clutch causing the shifting problems.
Before going to the service center, I believe this article will be able to provide you with insights on why you have the P0740 code and how you can fix your Chevy Silverado ridden with this issue. Keep on reading!
What Does P0740 Code Mean On Chevy Silverado?
P0740 is a very common transmission trouble code. It means that the computer in the Silverado has detected a problem with the torque converter clutch (TCC) solenoid circuit.
The TCC “locks” the drivetrain. It makes sure that a true mechanical connection between the transmission and the engine is possible.
Essentially, it effectively converts an automatic transmission to manual transmission. But at certain speeds and engine loads. And eliminates all transmission slipping.
So the code P0740 means that the control module (PCM or TCM – Transmission Control Module) has detected an electrical fault with the torque converter clutch solenoid or its circuit.
For now, let’s look at what the different parts of the code P0740 signify:
- P- Powertrain, the assembly of parts that move your car forward.
- 0 – Standardized code.
- 7 – Transmission.
- 40- Specific Problem (in this case the torque converter clutch circuit).
What Happens When the Code P0740 On Chevy Silverado Appears?
As there’s a problem with the transmission, the truck gets stuck in gears. Particularly the 3rd gear. You may also suddenly lose 5th and 6th gear while driving. The reverse works often but other times doesn’t.
Some electrical components may stop working. For example, the speedometer and the tach. The most common sign is that the truck will not shift by itself. With a transmission filled with fluid, shifting at speeds from 30mph up to 80mph on extended drives is no issue.
You will also be unable to start driving in the 1st gear. Only the 2nd gear may work in starting.
What Causes Code P0740 On Chevy Silverado?
These causes below are some of the primary ones generating the code P0740 in a Silverado:
- Loss of voltage to the transmission solenoid power supply circuit.
- Incorrect installation of any electronic aftermarket device (e.g: alarm clock, remote starter, etc).
- Ignition switch problem.
- Poor fuel quality. Having old and dirty oil makes the transmission act weird.
- Bad sensors.
- Power problem to the TCC solenoid.
- Damage to the internal harness in the transmission.
- The solenoid control circuit for the TCC is shorted to either B+ or ground.
- Test the TRANS fuse if the TCC solenoid power circuit is open.
- Failure of PCM, damage or failure of the TCC solenoid.
- Damaged wiring. Mice chew up the wiring under the Underhood fuse block often. You might want to look for a mouse nest there.
Other Symptoms Of Getting P0740 Code On Chevy Silverado
Here are some extra symptoms of the code P0740:
- The Silverado stutters.
- Check engine light comes up. The SES lights mainly light up in the mornings.
- Heated transmission causes higher RPMs.
- Issues in engaging the highest RPM.
- Converter not locking.
- Lack of transmission fluid.
- Dirty transmission fluid.
- GM codes P0753, P0758, P0785 and P1860 may show up along with this code.
How To Fix The P0740 Code On The Chevy Silverado?
Step 1
Check the electrical plug on the side of the transmission first. Check the connections, making sure there are no pulled or bent pins before disconnecting.
The first thing I would do is change the oil and add some transmedic to it. The old oil needs to be changed. If you’re feeling quite adventurous, you could remove the valve body, give it a thorough cleaning with a clean solvent, and then finish it off with hot water.
Put it back on after new lubrication with clean transmission fluid. If this does not fix the issue, it’s time to rebuild.
Step 2
If the transmission checks out well, it is time to troubleshoot the wiring. Fix or replace any damaged or chewed-up wiring under the hood.
Step 3
If the transmission’s wiring appears to be in good condition, change the TCC PWM solenoid. Once you remove the transmission pan, it will be on the front of the valve body, on the passenger side:
In the first slot behind the solenoid, there is a retainer (see image) that holds the solenoid in place.
The solenoid can then be removed by pulling it out directly after the retainer has been forced out (down) using a small flat-bladed screwdriver.
It is frequently referred to as a “TCC PWM Solenoid.” Drop the pan and replace the TCC Solenoid, both shift solenoids, and the 2-3 Shift Module. This module resembles the TCC Solenoid almost exactly but differs in the location of its pins on the clip, filter, and fluid.
Step 4
Verify that the appropriate fuse is receiving battery voltage during operation if the vehicle has an aftermarket electronic device installed. And the DTCs are set when the device is in use.
These DTCs will be set if the voltage is not available at this fuse because solenoids lack voltage. A remote starting system installed improperly is what causes it.
Keep in mind that repair of an aftermarket installation of accessories is non-warrantable. Use the system installer so that adjustments can be made in this case.
Step 5
Check the battery voltage at the circuit fuse in the transmission solenoid power supply circuit while the ignition switch is in the RUN position. For information on the transmission solenoid power supply circuit, consult the relevant SI Document.
Check the ignition voltage circuit between the fuse and the transmission for any potential ‘opens’. Check if the fuse has battery voltage. If it doesn’t, check for continuity between the fuse and the ignition switch.
Repair the open in that circuit if there is NO continuity between the fuse and the ignition switch.
The ignition switch is most likely to be the culprit if there is continuity between the fuse and the ignition switch. Use the appropriate Ignition Switch Replacement procedure in SI to replace the ignition switch.
For information on the ignition switch’s use and part description, see group number 2.188 of the parts catalog.
Step 6
If the PCM has failed, the TCC solenoid is damaged, or has failed, refer to the TSB 01-07-30-002C. Check and replace bad fuses, and failed sensors (by checking them with a multimeter) especially if you have more than one code for bad transmission.
How Much Does It Cost To Fix The Chevy Silverado P0740 Code?
1. Transmission
For a new transmission, the Chevy Silverado transmission replacement price starts at $5,000 or more. Rebuilding a transmission completely rather than replacing it is preferable. A new transmission for a 2015 Chevrolet Silverado 1500 could cost more than $3,500.
The fluid change of the transmission costs $76=80 for the fluid and $120-190 for labor. Cleaning and lubricating may cost extra.
2. Lgnition Switch
Replacement ignition switches for Chevrolet Silverado 1500s typically cost between $130 and $160. This includes parts and labor.
3. Diagnostics and Others
For between $114 and $130, a check engine light diagnostic can be performed. Overall the service costs may reach up to $300.
Can You Drive Your Chevy Silverado With Code P0740?
No. It is highly advised that you don’t. The P0740 error code can cause issues with driving.
Your Silverado may as well break down in the middle of nowhere. All because of the shortcomings that the code signifies.
An engine is powerless without the transmission. It is best to have this problem diagnosed and repaired as soon as possible.
Frequently Asked Questions (FAQs)
What is the most common mistake while diagnosing P0740?
Assuming that the issue is related to driveline problems, internal transmission problems, or engine misfire problems. While it may only be a malfunctioning TCC solenoid or dirty/contaminated transmission fluid, it is common to assume that the torque convertor itself needs to be replaced or rebuilt.
Where does the solenoid attach to in the Chevy Silverado?
The 3-2 downshift is managed by the 3-port, normally-closed SS valve assembly of the 3-2 shift solenoid. In the transmission, the solenoid is connected to the control valve body. Circuit 1020 delivers ignition voltage to the solenoid.
What is the TCC solenoid valve?
The fluid acting on the converter clutch valve is managed by the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The application and release of the TCC are managed by the converter clutch valve.
Conclusion
So you can see what the P0740 code is and how it can be fixed. I have also discussed the kind of budget you will have to fix for troubleshooting these problems.
If you have read the article till here you are ready to fight the code P0740. Good luck!
