[SOLVED] P1838 Code: Fix High Voltage Issue With Internal Mode Switch ‘a’

The automobile fault code P1838 indicates a problem with the Transmission Internal Mode Switch.

This can cause the Engine Light to turn on or the Service Engine Soon Warning Light to illuminate. The possible causes include a faulty switch, an open or shorted harness, poor electrical connection, or a faulty Transmission Control Module (TCM).

To fix this issue, you should visually inspect the wiring harness and connectors for any damage.

Look for broken, bent, pushed out, or corroded pins on the connectors. The repair time for this issue is estimated to be around 1.0 hour. It is important to address this problem promptly to prevent further damage to the transmission.

Repair Importance Level10.0 (Out of 10)
Estimated Repair TimeApproximately 1.0 hour
Repair Difficulty Level10.0 (Out of 10)

When the engine light is on or the service engine soon warning light is illuminated, it could be a sign of the p1838 fault code.

  • The symptoms of the automobile fault code P1838 include the Engine Light being ON or the Service Engine Soon Warning Light being illuminated.

The automobile fault code P1838 can be caused by a faulty Transmission Internal Mode Switch, an open or shorted harness, a poor electrical connection in the circuit, or a faulty Transmission Control Module (TCM).

  • The fault code P1838 can be caused by the following: a faulty Transmission Internal Mode Switch, an open or shorted Transmission Internal Mode Switch harness, a poor electrical connection in the Transmission Internal Mode Switch circuit, or a faulty Transmission Control Module (TCM).

To fix the automobile fault code p1838, start by visually inspecting the wiring harness, connectors, and components for any damage or corrosion.

  • To fix the automobile fault code P1838, follow these steps: 1.
  • Check the possible causes mentioned above.
  • 2.
  • Visually inspect the wiring harness and connectors related to the fault code.
  • 3.
  • Look for any damaged components.
  • 4.
  • Check for broken, bent, pushed out, or corroded pins in the connectors.
  • The estimated repair time for this fix is 1.0 hour.

The factors influencing the cost of diagnosing and fixing the automobile fault code P1838 are the estimated repair time of 1.0 hour and the typical auto repair shop charges of $75 to $150 per hour.

The P1838 fault code refers to the Internal Mode Switch ‘A’ Circuit High Voltage. This code is related to the Transmission Control Module (TCM) and indicates that the TCM has detected a voltage reading greater than 2.38V on the internal mode switch A signal circuit for 1.75 seconds. The internal mode switch is made up of 5 separate hall effect switches, each supplied with a 9V reference circuit and a signal circuit from the TCM.

These signal circuits indicate the gear position selected by the vehicle operator. Each gear selector position will have a specific voltage reading, either 0.70-0.96V indicating On or 1.68-2.38V indicating Off. When the TCM detects a voltage reading higher than 2.38V on the internal mode switch A signal circuit for a prolonged period, it triggers the P1838 fault code.

This code helps identify issues with the internal mode switch circuit, which can affect the proper functioning of the transmission system.

It is important to address this fault code promptly to ensure the smooth operation of the vehicle.

What are the possible causes of the automobile fault code P1838?

If you see the engine light on or the service engine soon warning light, the fault code P1838 could be the culprit. This code is often caused by a faulty transmission internal mode switch, an open or shorted harness, a poor electrical connection in the switch circuit, or a faulty transmission control module (TCM). To fix the issue, start by visually inspecting the wiring harness and connectors. Look for any damaged components and check for broken, bent, pushed out, or corroded connector pins.

How can I visually inspect the wiring harness and connectors to fix the P1838 fault code?

If you’re dealing with the P1838 fault code and your engine light is on, it’s time to take action. The culprit could be a faulty Transmission Internal Mode Switch or issues with the wiring harness and connectors. To fix this, visually inspect the wiring harness and connectors for any damage or poor electrical connections. Look out for broken, bent, pushed out, or corroded pins on the connectors. Don’t delay, check these possible causes and get your vehicle back on track.

What should I look for when checking for damaged components and connector pins to resolve the P1838 fault code?

When resolving the P1838 fault code, start by checking for damaged components and connector pins. This can be done by visually inspecting the related wiring harness and connectors. Look for any signs of damage such as broken, bent, pushed out, or corroded connector pins. By doing so, you can identify any issues with the Transmission Internal Mode Switch or the Transmission Control Module and take the necessary steps to fix them.

p1838 error fault code explained

If you’re seeing the Engine Light ON or the Service Engine Soon Warning Light, it could be due to a faulty Transmission Internal Mode Switch or issues with the wiring harness and connectors.

To fix it, visually inspect the wiring and connectors, check for damaged components, and look for any broken, bent, pushed out, or corroded pins on the connectors.

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