Faulty shift solenoid 'B' (open or shorted coil); Damaged or corroded wiring harness or connector at the solenoid; Open or shorted circuit in the wiring between the TCM and solenoid; Poor electrical connection at the TCM connector; Internal transmission mechanical issues causing solenoid damage (less common); Contaminated transmission fluid causing solenoid malfunction (rare)

DTC codes / P07xx · Transmission / P0758

P0758Shift Solenoid 'B' Electrical

Q: What does code P0758 mean?

Shift Solenoid 'B' Electrical. P0758 is a generic OBD-II code indicating an electrical fault in the circuit for shift solenoid 'B', which is one of the solenoids the transmission control module (TCM) uses to control gear shifts. The TCM monitors the solenoid's electrical circuit and sets this code when the current or voltage is outside the expected range, often due to an open, short, or high resistance in the wiring or solenoid itself.

P0758 is a generic OBD-II code indicating an electrical fault in the circuit for shift solenoid 'B', which is one of the solenoids the transmission control module (TCM) uses to control gear shifts. The TCM monitors the solenoid's electrical circuit and sets this code when the current or voltage is outside the expected range, often due to an open, short, or high resistance in the wiring or solenoid itself.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Check engine light or transmission warning light illuminated
Transmission may shift harshly or flare between gears
The transmission may stay in a single gear (limp mode) or fail to shift
Delayed or erratic shifting, especially when cold
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Faulty shift solenoid 'B' (open or shorted coil)
Damaged or corroded wiring harness or connector at the solenoid
Open or shorted circuit in the wiring between the TCM and solenoid
Poor electrical connection at the TCM connector
Internal transmission mechanical issues causing solenoid damage (less common)
Contaminated transmission fluid causing solenoid malfunction (rare)

How to diagnose and fix it

Scan all modules for stored and pending codes to confirm P0758 is the only transmission code.
Inspect the solenoid 'B' connector and wiring for damage, corrosion, or loose pins.
Measure the resistance of solenoid 'B' with a multimeter and compare to the manufacturer's specification.
Check for continuity and shorts in the wiring between the TCM and solenoid 'B'.
If the circuit tests good, test the TCM output signal with an oscilloscope or bidirectional scan tool.
Replace the faulty solenoid 'B' if resistance is out of spec or the coil is open/shorted.
Clear codes and perform a road test to verify the repair and ensure no other codes return.

Shift Solenoid B Circuit Checks

A P0758 can be set by a simple loose or corroded connector, so always inspect the harness before condemning the solenoid.
The solenoid's resistance can change with temperature, so test it both cold and after warming the transmission to catch intermittent faults.
Some vehicles use a single solenoid for multiple gears, so a failed 'B' solenoid may cause different shift patterns than expected.
A faulty TCM or a poor ground can mimic a solenoid circuit fault, so verify powers and grounds before replacing parts.
After replacing a solenoid, the transmission adaptive learning may need to be reset with a scan tool to restore proper shift quality.

Can I keep driving with P0758?

You can usually drive the vehicle with P0758, but the transmission may enter limp mode or shift harshly, so avoid aggressive acceleration and highway speeds until repaired. Prolonged driving with a faulty solenoid can cause additional transmission damage, so schedule diagnosis soon.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.