AutoCodes – Cadillac – P0842 Cadillac

P0842 Cadillac Code - Transmission Fluid Pressure Switch 1 Circuit Low Voltage

Quick Answer

The Transmission Fluid Pressure (TFP) switch 1 is part of the control solenoid valve assembly, which has no serviceable parts. Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly. 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: P0842 Cadillac indicates Transmission Fluid Pressure Switch 1 Circuit Low Voltage.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Transmission Control Solenoid Valve Assembly.
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 10,973

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 Aug 02, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0842 Cadillac Description

The Transmission Fluid Pressure (TFP) switch 1 is part of the control solenoid valve assembly, which has no serviceable parts. The Transmission Control Module (TCM) supplies a signal circuit to the TFP Switch 1. The TFP Switch 1 has an internal case ground. TFP Switch 1 is normally closed or LOW. When oil pressure is present at the TFP Switch 1, the switch is open or HIGH. The normally high clutch pressure control (PC) solenoid 2 controls pressure to the 3-5 reverse clutch regulator valve. The TCM monitors the TFP switch 1 to determine the position of the 3-5 reverse clutch regulator valve. When the 3-5 reverse clutch is commanded OFF, pressure is present on the TFP switch 1. When the 3-5 reverse clutch is commanded ON, the 3-5 reverse clutch regulator valve moves and pressure to the TFP switch 1 is exhausted through the 3-5 reverse clutch regulator valve. The Diagnostic Trouble Code (DTC) will be set when the TCM detects that the TFP switch 1 signal voltage remains LOW after the 3-5-R clutch transitions from a HIGH pressure state to a LOW pressure state. The TCM counts each incident. The DTC sets when 25 counts are accumulated.

OBDII Code P0842 Cadillac - Transmission Fluid Pressure Switch 1 Circuit Low Voltage - AutoCodes.com — P0842 Cadillac Code - Transmission Fluid Pressure Switch 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0842 Cadillac?

Low transmission fluid level
Dirty transmission fluid
Faulty Transmission Control Solenoid Valve Assembly
Transmission Control Solenoid Valve Assembly harness is open or shorted
Transmission Control Solenoid Valve Assembly circuit poor electrical connection

How to Fix the DTC P0842 Cadillac?

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 P0842 Cadillac 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.

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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 P0842 Cadillac Code

No Frequently Asked Questions about P0842 Cadillac Code found.

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Ray Haken
Date: March 5, 2022 at 10:32 pm

08 Cadillac Escalade, won’t go into drive or reverse, fluid is full and clean, has PO842 code. Cleared that code once, started rig and it went into forward and reverse. Unplugged scanner went to put it into gear and nothing. Crawled under rig checked connection into tranny( didn’t unplug, just pushed in on wires) started rig put into forward and reverse and had movement. Put things away and went to move rig and nothing.....do I replace the TCM or what ? I haven’t changed any parts yet....Ray

Reply to Comment
OBDIITech
Date: March 7, 2022 at 6:06 pm

Unfortunately, due to the age of your vehicle and the type of code, it's more likely that you have a mechanical problem instead of TCM problem. My only recommendation is to have a transmission shop inspect the transmission for you.

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