Fix P0739: STEP-BY-STEP diagnostic GUIDE!

The P0739: TCM Engine Speed Output Circuit High refers to a fault where the transmission control module (TCM) detects a high signal from the engine speed output circuit. This issue can stem from wiring problems, faulty components, or an electrical malfunction within the circuit.

P0739 – Quick Overview

CodeInformation
MeaningP0739: TCM Engine Speed Output Circuit High
Is it serious?Yes, this can cause communication errors between the engine and TCM, leading to improper transmission operation.
Possible causes– High signal from TCM engine speed output circuit
– Faulty circuit or components
– Wiring issues
How to diagnose?– Test the circuit for high signal
– Inspect wiring and connectors
– Replace faulty components if necessary

P0739 Meaning

The P0739 code indicates that the transmission control module (TCM) is receiving a higher-than-expected signal from the engine speed output circuit. This may result from an issue with the circuit itself, faulty components, or damaged wiring. If left unresolved, it can lead to communication issues between the engine and the transmission, affecting performance.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for additional transmission-related or engine codes that could provide further insights.OBD-II Scanner
Test the Circuit for High SignalUse a multimeter or diagnostic tool to measure the signal from the TCM engine speed output circuit and verify if it is above specifications.Multimeter, Diagnostic Scanner
Inspect Wiring and ConnectorsInspect the wiring and connectors between the engine speed sensors and the TCM for any signs of wear, corrosion, or damage.Flashlight, Multimeter, Safety Gloves
Check for Electrical FaultsTest for any electrical faults such as short circuits, which may be causing the signal to be too high.Circuit Tester, Multimeter
Replace Faulty ComponentsReplace any damaged wiring, connectors, or components in the circuit that are contributing to the high signal issue.Replacement Parts, Wrenches, Screwdrivers
Clear the Code and Test DriveAfter making repairs, clear the code using an OBD-II scanner and perform a test drive to ensure the problem is resolved.OBD-II Scanner
Recheck for CodesAfter the test drive, rescan the vehicle to ensure the P0739 code has not returned.OBD-II Scanner
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