Kick-down switch internally shorted or stuck closed; Wiring short to earth or to another circuit in the kick-down switch harness; Corroded, damaged or loose connector at the switch or control module; Accelerator pedal or throttle assembly mechanically misadjusted so the switch is held pressed; Fault in the throttle position or pedal position signal the module compares against the switch; Faulty transmission control module or outdated software calibration.

P1837

Kick-Down Switch Failed Short.

GMC
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
8: AreaTransmission
37: FaultThe specific fault in that area

What it means

P1837 on a GMC means the transmission control module has detected the kick-down switch circuit as shorted. The kick-down switch tells the control unit when the accelerator is pushed fully down so it can command a downshift. The code sets when the switch signal reads as permanently active or does not match the throttle position or pedal input the module expects.

Symptoms

Malfunction indicator lamp or transmission warning lamp on
Transmission stuck in one gear or fixed in a limp-home mode
Unexpected, harsh or unwanted downshifts
No kick-down response when the accelerator is pressed fully
Poor acceleration or erratic shift timing
Reduced fuel economy

Possible causes

Kick-down switch internally shorted or stuck closedlikely
Wiring short to earth or to another circuit in the kick-down switch harnesslikely
Corroded, damaged or loose connector at the switch or control modulepossible
Accelerator pedal or throttle assembly mechanically misadjusted so the switch is held pressedpossible
Fault in the throttle position or pedal position signal the module compares against the switchpossible
Faulty transmission control module or outdated software calibrationrare

How to diagnose

Read all stored and pending codes and record the freeze frame data, noting any throttle or pedal position codes
Inspect the accelerator pedal, linkage and switch area for obstruction, damage or misadjustment that could hold the switch closed
Visually inspect the kick-down switch wiring and connectors for chafing, water ingress, corrosion and pushed-back pins
Watch the live kick-down switch status with a scan tool while moving the pedal slowly from rest to full travel and check it changes only at full travel
Check the live throttle or pedal position reading is smooth and consistent across the full range
Disconnect the switch and check its resistance and continuity in both positions against the manufacturer specification for your model and transmission
Test the switch circuit for short to earth or to another circuit between the switch and control module, with the module disconnected
Check for applicable software updates or technical bulletins for your specific model and transmission before condemning the control module

How to fix

Replace the kick-down switch if it is shorted or stuck
Repair or replace the damaged wiring section causing the short
Clean, repair or replace corroded or damaged connectors and terminals
Correct the pedal or throttle linkage adjustment, or replace the faulty pedal or throttle assembly
Repair any throttle or pedal position sensor fault found
Update the control module calibration if an outdated one is a known cause for your model, and replace the module only once all else is proven good

Can I keep driving?

Medium severity

The car can usually be driven short distances, but expect odd shifting or limp-home behaviour that may get worse. Have it checked soon to avoid unwanted downshifts or extra transmission wear.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.