AutoCodes – Generic – P1842

P1842 Code - 1-2 Shift Solenoid Circuit Low Input Voltage

Quick Answer

With the engine runtime over 5 seconds, system voltage from 8-18v, Fuel Cutoff inactive, the Powertrain Control Module (PCM) detects an open circuit or a short to ground on the 1-2 Shift Solenoid feedback circuit for 4.3 seconds. Common causes include Faulty 1-2 Shift Solenoid, 1-2 Shift Solenoid harness is open or shorted, 1-2 Shift Solenoid circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1842 indicates 1-2 Shift Solenoid Circuit Low Input Voltage.
Common causes: Common causes include Faulty 1-2 Shift Solenoid, 1-2 Shift Solenoid harness is open or shorted, 1-2 Shift Solenoid circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 19,502

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 22, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1842 Description

OBDII Code P1842 - 1-2 Shift Solenoid Circuit Low Input Voltage - AutoCodes.com — P1842 Code - 1-2 Shift Solenoid Circuit Low Input Voltage

What does this mean?

What are the Possible Causes of the DTC P1842?

Faulty 1-2 Shift Solenoid
1-2 Shift Solenoid harness is open or shorted
1-2 Shift Solenoid circuit poor electrical connection

How to Fix the DTC P1842?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1842 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1842 code?

Need more information on how to fix the P1842 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1842 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1842 Buick — 1-2 Shift Solenoid Circuit Low Input Voltage
P1842 Cadillac — 1-2 Shift Solenoid Circuit Low Input Voltage
P1842 Chevrolet — 1-2 Shift Solenoid Circuit Low Input Voltage
P1842 GMC — 1-2 Shift Solenoid Circuit Low Input Voltage
P1842 Pontiac — 1-2 Shift Solenoid Circuit Low Input Voltage
P1842 Saturn — 1-2 Shift Solenoid Circuit Low Input Voltage

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1842 Code

1. What are the common symptoms of OBDII code P1842 (1-2 Shift Solenoid Circuit Low Input Voltage)?

The common symptoms of P1842 include harsh shifting between first and second gear, delayed or erratic shifting, and potential transmission slipping.

2. What are the possible causes of OBDII code P1842?

Potential causes of P1842 include a faulty 1-2 shift solenoid, damaged wiring or connectors in the solenoid circuit, low transmission fluid levels, or a malfunctioning transmission control module.

3. How can I diagnose the underlying issue causing OBDII code P1842?

Diagnosing P1842 involves checking the transmission fluid level and condition, inspecting the wiring and connectors related to the 1-2 shift solenoid, and using a professional OBDII scanner to pinpoint the exact fault.

4. Can I continue driving with OBDII code P1842 present?

It is not recommended to continue driving with P1842 active, as it can lead to further damage to the transmission and potentially result in unsafe driving conditions.

5. How can I repair OBDII code P1842 (1-2 Shift Solenoid Circuit Low Input Voltage)?

Repairing P1842 typically involves replacing the faulty 1-2 shift solenoid, repairing or replacing damaged wiring, ensuring proper transmission fluid levels, and clearing the trouble code with an OBDII scanner.

6. Is it possible for a DIY enthusiast to fix OBDII code P1842 at home?

Depending on your skill level and access to tools, it may be possible to address P1842 at home by following repair guides and videos. However, complex transmission issues may require professional expertise.

7. How much does it cost to repair OBDII code P1842?

The cost of repairing P1842 can vary depending on the extent of the issue and whether you choose to do the repairs yourself or seek professional help. Costs may include parts, labor, and diagnostic fees.

8. Can low transmission fluid cause OBDII code P1842 to trigger?

Yes, low transmission fluid levels can lead to P1842 being triggered, as inadequate fluid can affect the proper functioning of the 1-2 shift solenoid and other transmission components.

9. Are there any preventive measures to avoid OBDII code P1842 in the future?

Regularly servicing and maintaining your transmission, checking transmission fluid levels, addressing any leaks promptly, and avoiding aggressive driving can help prevent issues like P1842 from occurring.

10. How long does it typically take to repair OBDII code P1842?

The repair time for P1842 can vary depending on the specific cause of the issue, the availability of parts, and whether you are doing the repairs yourself or taking your vehicle to a professional.