Corroded, loose, or damaged battery terminals and cables causing intermittent voltage drop; A failing or weak vehicle battery that drops below threshold during cranking or load; A faulty ignition switch or ignition relay that interrupts power to the TCM circuit; Blown or intermittent fuse in the TCM supply circuit, or a poor fuse box connection; Chafed or broken wiring in the TCM power feed, especially near harness bends or connectors; A failing TCM itself with an internal voltage regulator fault; A poor ground connection at the TCM or engine block causing reference voltage instability

DTC codes / GM codes / P1760

P1760 · GMTCM Supply Voltage Interrupted

Q: What does code P1760 mean?

TCM Supply Voltage Interrupted. P1760 on a GM vehicle means the Transmission Control Module (TCM) has detected that its supply voltage was interrupted or dropped below a usable threshold during operation. The TCM logs this code when the ignition voltage feed to the module momentarily falls out of range, which can reset the module or cause it to lose adaptive memory and shift control.

P1760 on a GM vehicle means the Transmission Control Module (TCM) has detected that its supply voltage was interrupted or dropped below a usable threshold during operation. The TCM logs this code when the ignition voltage feed to the module momentarily falls out of range, which can reset the module or cause it to lose adaptive memory and shift control.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Transmission may default to a limp or fail-safe mode with harsh or delayed shifts
The check engine light or transmission warning light illuminates on the dash
Erratic or inconsistent shift points that change from drive to drive
The transmission may slip or feel like it is in neutral briefly during acceleration
Often no symptoms besides the warning light if the voltage interruption was brief
Loss of adaptive shift memory causing firm or soft shifts after a battery service

Common causes, most likely first

Corroded, loose, or damaged battery terminals and cables causing intermittent voltage drop
A failing or weak vehicle battery that drops below threshold during cranking or load
A faulty ignition switch or ignition relay that interrupts power to the TCM circuit
Blown or intermittent fuse in the TCM supply circuit, or a poor fuse box connection
Chafed or broken wiring in the TCM power feed, especially near harness bends or connectors
A failing TCM itself with an internal voltage regulator fault
A poor ground connection at the TCM or engine block causing reference voltage instability

How to diagnose and fix it

Perform a battery and charging system test, including a load test and check for voltage drop during cranking
Inspect and clean battery terminals, ground straps, and the TCM ground connection for corrosion or looseness
Check the TCM supply fuse and relay, and verify voltage at the TCM power pin with the key on and during cranking
Wiggle-test the TCM harness and connectors while monitoring supply voltage to locate intermittent opens
Repair any chafed wires or replace damaged connectors in the TCM power feed circuit
If voltage supply is confirmed good, test the TCM for internal faults and replace if necessary
Clear the code and perform a relearn or adaptive drive cycle to confirm the repair

Voltage drops you will miss on a scan tool

A battery that passes a static voltage test can still drop below the TCM threshold during cranking, so a load test and cranking voltage check are essential before condemning the module.
The TCM supply circuit often shares a fuse or relay with other modules, so a blown fuse may be caused by a short elsewhere rather than a TCM fault.
Intermittent voltage interruptions from a loose ground can set P1760 without ever storing a battery or charging system code, leading to misdiagnosis of the transmission itself.
After repairing the voltage supply, the TCM may need an adaptive relearn because the interruption can wipe shift adapts, and the customer may still complain of harsh shifts until the relearn completes.
A failing ignition switch can interrupt TCM power only over bumps or at certain key positions, so road testing while monitoring TCM voltage is often the only way to catch it.

Can I keep driving with P1760?

You can usually drive the vehicle to a shop, but avoid heavy acceleration and towing because the transmission may enter limp mode or shift unpredictably. If the transmission is stuck in a single gear or the warning light is flashing, stop driving and have it towed to prevent internal damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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