P1860 code — how to fix error fast
Dive into the world of torque converter clutch with the P1860 code. Understand its importance for smooth gear transitions.
Facing a serious OBD2 error code like the P1860 code can be a challenging task and most drivers are tempted to simply try clearing it out and keep on driving. However, if you know a bit more about the P1860 code meaning, you’ll also understand the possible consequences of not acting on time to repair the underlying issue.
That’s why our team has decided to give you a helping hand at this, as we’ll go over the main possible causes of the code, diagnostic methods, and solutions. We’ll also help you avoid facing the code anytime soon in the future, so let’s get right into it.
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What does the P1860 code mean?
The P1860 code refers to a problem with the transmission control circuit in the vehicle’s engine control module (ECM). Specifically, it means that the ECM has detected an issue with the solenoid valve circuit in the transmission. This code is important for drivers to fix because it can cause significant problems with the transmission, which can lead to a breakdown or even an accident.
In other words, if the code affects the transmission solenoid issues, it can lead to rough shifting and problems with the transmission’s performance. In the worst-case scenario, this can even lead to a safety risk, so it’s best to keep the issue at bay by taking swift repair action.
What causes the P1860 code?
Several potential causes can trigger the P1860 code, including a faulty shift solenoid valve, a damaged wiring harness, a poor electrical connection, or a failed transmission control module (TCM).
Symptoms that may be present with the P1860 code include transmission slipping, difficulty shifting gears, and an illuminated check engine light,n and it all depends on the exact culprit behind the code, so here’s a list of possible scenarios.
Faulty Shift Solenoid Valve
The shift solenoid valve is responsible for controlling the flow of transmission fluid in the transmission. If this valve fails, it can cause the P1860 code to appear. Symptoms of a faulty shift solenoid valve include harsh shifting or transmission that will not shift at all.
Damaged wiring harness
The wiring harness carries the electrical signals from the transmission to the TCM. If the wiring harness is damaged, it can cause a short circuit and trigger the P1860 code. Symptoms of a damaged wiring harness include intermittent transmission issues or an illuminated check engine light.
Poor electrical connection
A poor electrical connection between the TCM and the shift solenoid valve can also cause the P1860 code to appear. Symptoms of a poor electrical connection include a transmission that slips or delays shifting.
Failed transmission control module
If the TCM fails, it can cause the P1860 code to appear. Symptoms of a failed TCM include a transmission that does not shift correctly or an illuminated check engine light.
Which car models does the P1860 code affect the most?
The P1860 code is most commonly found in General Motors vehicles, such as Chevrolet, GMC, and Buick. However, it is not limited to these brands and can appear in other car models as well. Some of the car models that have a higher incidence of the P1860 code include the following:
- Chevy Silverado: This car model is known to face issues with code P1860 due to problems with electrical connections and the control module operation.
- GMC Sierra: This car model has been known to be affected by code P1860 due to premature wear of the shift solenoid valve.
- Buick Century: The Century is yet another car model that is commonly affected by the code P1860 because of the issues with the TCM.
How to diagnose the P1860 code
Diagnosing the P1860 code requires specialized diagnostic tools, such as an OBD-II scanner, a multimeter, and a wiring diagram. The following steps can be taken to diagnose the P1860 code:
Connect the OBD2 scanner
Connect the OBD-II scanner to the car’s diagnostic port and retrieve the codes. If the P1860 code appears, proceed to the next step.
Inspect the wiring harness
Inspect the wiring harness for any signs of damage or corrosion. Repair or replace any damaged wires or connectors.
Check the shift solenoid valve
Use the multimeter to check the shift solenoid valve’s resistance. If the resistance is outside the manufacturer’s specifications, replace the valve.
Check the electrical connection
Check the electrical connection between the TCM and the shift solenoid valve. Repair or replace any damaged or corroded connectors.
Check the TCM
If all other potential causes have been ruled out, check the TCM for any signs of damage or failure. Replace the TCM if necessary.
How to fix the P1860 code
Fixing the P1860 code depends on the underlying cause. Potential fixes include replacing the shift solenoid valve, repairing or replacing the wiring harness, cleaning or replacing the electrical connection, or replacing the TCM. Here’s a detailed list of steps you can take to fix the problem:
Replace the TCC solenoid
The TCC PWM solenoid is the component that controls the flow of transmission fluid to the torque converter clutch. If it’s malfunctioning, it can trigger the P1860 code. In some cases, simply replacing the TCC PWM solenoid can fix the issue and clear the code.
Replacing the driver module
The driver module is responsible for controlling the TCC PWM solenoid circuit. If it’s sending incorrect signals, it can trigger the P1860 code. In some cases, simply replacing the driver module can fix the issue and clear the code.
Repair the wiring harness
As mentioned earlier, damaged or corroded wiring harnesses can contribute to the P1860 code. In some cases, repairing or replacing these wiring harnesses can fix the issue and clear the code.
Update the software
In some cases, updating the software of the vehicle’s powertrain control module (PCM) may be necessary to fix the P1860 code. This is because newer software versions may address known issues with the TCC PWM solenoid circuit.
How to prevent the P1860 code
The best way to prevent the P1860 code is to perform routine maintenance on the transmission system, such as taking the following actions:
- Checking the fluid levels
- Replace the transmission filter regularly
- Check the system for damage
By keeping in mind the mentioned ways of fixing and preventing the code, you can at least avoid having to deal with it again in the near future.
Our take
In the end, all the trouble with the code P1860 can be solved by taking prompt action and fixing minor issues that are nothing compared to doing transmission rebuilds. As long as you act on time, it’s possible to avoid paying thousands of dollars on transmission rebuilds, so we hope that this guide was enough to help you with that.
What does the P1860 code mean?
The P1860 code indicates that there is a problem with the torque converter clutch pulse width modulation (TCC PWM) solenoid circuit. This circuit is responsible for controlling the flow of transmission fluid to the torque converter clutch.
How do I know if I have a P1860 code?
If your vehicle’s onboard diagnostic system detects an issue with the TCC PWM solenoid circuit, it will trigger the P1860 code and illuminate the check engine light on your dashboard.
Can I still drive my car with a P1860 code?
While it’s possible to drive your car with a P1860 code, it’s not recommended. Ignoring the issue can lead to further damage to your transmission and more costly repairs down the line. It’s best to have your vehicle diagnosed by a qualified mechanic and repaired as soon as possible.
