If you are experiencing the code P1738 on your Honda Accord, it means that there is a problem with the second clutch pressure switch circuit and that would require pinpoint tests to narrow down the problem to either sensors or another issue.
A second clutch pressure switch can be found on the transmission, where it is very easy to locate. In my opinion, the wiring should be checked, and if the wiring needs to be replaced, I would do so immediately. Likewise, it is recommended that you replace the switch if it is leaking.
It is the PCM that determines if there is enough pressure in the system to move the transmission or not by using the pressure switch. Therefore, in the absence of any symptoms, you can drive for a while if you are not experiencing any symptoms.
However, since it is not caused by a fault with the internal trans, we should be able to resolve the problem quite easily.
P1738 Honda Code Meaning
A second clutch pressure switch or a second clutch oil press switch is normally an open switch, but when a second clutch oil press is applied to it, the switch closes.
This information is used by the Powertrain Control Module (PCM) to adjust the hydraulic pressure application timing based on information obtained from the switch.
There is a sensor on the Powertrain Control Module that monitors the pressure in the second clutch.
A Diagnostic Trouble Code (DTC) will be set by the Powertrain Control Module when it detects the Faulty 2nd Clutch Pressure Switch and flags it as a Diagnostic Trouble Code (DTC).
How To Fix Code P1738?
The problem is with the transmission system, and the cost would be dependent on what is causing the problem. In some cases, it might be an issue with the wire connection, a faulty pressure switch, or even an issue with the PCM.
Start by checking the “Possible Causes” listed above to determine the root cause of the problem. Make sure that the wiring harness and connectors related to the wiring harness have been inspected visually. The connector’s pins should be checked for broken, bent, pushed-out, or corroded components, as well as broken, bent, or pushed-out components.
There is no better way to check if any computer codes have come back than to clear them and see if any come back. The scanner you need for this will need to be able to clear codes in order for you to accomplish this.
Or, if you happen to be near an auto service center, they may be able to help you out. My first course of action will be to take the car back to the transmission shop if P1738 returns.
Installing A 2nd Clutch Pressure Switch
Let me show you how to install a 2nd clutch pressure switch on a 2002 Honda Accord.
- First, take the intake off to make room for the installation. Depending on the vehicle, there will be four clips that you need to take off.
- Clamp off the hose intake that holds the intake to the intake manifold. If you only have the code P1738, which is a fairly common problem with Honda Accord, you will find the parts almost in any local auto shop.
- After you take the intake out, you will see the lower radiator hose. Take that off. There is a tube right under the lower radiator hose.
- Pull that out and push it down because you will need all the space you can get. Then check your manual to locate the actual sensor.
- There will be a green sensor. Take that out.
- You will need to use a medium-sized crescent wrench. At this point, check the actual plug to make sure there is no damage to it.
- Now put a new sensor. And attach all the things that you plugged out.
How Much Does It Cost To Diagnose The Code P1738 Honda?
There is a charge of 1 hour of labor involved in diagnosing the P1738 Honda error code. Diagnostic time and labor rates are affected by your location, the make and model of your vehicle, and even the type of engine you have.
There is a general range of $75 – $150 per hour that auto repair shops charge their customers to fix the P1738 Honda Accord problem.
Note About P1738 Honda Code
This transmission has a problem with its second clutch pressure switch. The engine’s processor has to be tested to ensure it is not faulty, or there is no problem with the wiring.
Once the second clutch pressure switch has been tested, you might have to replace it if it has been found to be defective. It is possible to do this externally. There seems to be a small cost involved, maybe less than $200.
As far as I’m concerned, the code may only be masking a problem on the inside. It is possible that even after replacing the switch if that is what turns out to be the case, there might still be an internal issue that needs to be addressed. Therefore, you should be cautious.
The Bottom Line
Again, this is a common problem and should be easy to fix. If you have a Honda Accord and get the P1738 code, follow the steps mentioned here to fix it. If not, bring your car to any Honda service center to fix it.
Also, you might get this code along with the P1486. If that happens, contact a mechanic and have him fix it for you.