P1837

What it means

P1837 on a Chevrolet means the powertrain control module has detected a short in the kick-down switch circuit. The kick-down switch tells the control unit when the accelerator is pressed fully down so the automatic transmission can force a downshift. The code sets when the switch signal reads as permanently active or shorted when the throttle position does not agree with it.

Symptoms

• Transmission downshifts unexpectedly or stays in a lower gear
• Transmission fails to shift up at normal points or shifts harshly
• No kick-down response or erratic response when the accelerator is floored
• Poor fuel economy from held lower gears
• Malfunction indicator lamp on, possibly with a transmission warning or limp mode

Possible causes

• Kick-down switch stuck or internally shorted, often at the accelerator pedal or throttle linkagelikely
• Switch signal wiring shorted to ground or to another circuit, from chafing or damaged insulationlikely
• Corroded, loose or water-contaminated connector at the switch or control unitpossible
• Pedal or throttle linkage misadjusted so the switch is held pressedpossible
• Fault in the throttle position signal that the control unit compares with the switchpossible
• Faulty powertrain control module or transmission control unitrare

How to diagnose

1. Read all stored and pending codes and note freeze frame data, including throttle position and vehicle speed, at the time the fault set
2. Check for related throttle position or transmission codes that could point to a shared cause
3. Inspect the kick-down switch, pedal assembly and linkage for damage, sticking or incorrect adjustment
4. Inspect the switch wiring and connectors for chafing, corrosion, moisture and pushed-back pins
5. Watch the switch status on a scan tool while pressing and releasing the accelerator, and see whether it changes state correctly
6. With the connector unplugged, test the switch for correct open and closed readings against the manufacturer's specification
7. Check the signal wire for shorts to ground and to other circuits, and check supply and ground to the switch
8. Only after wiring and switch are proven good, check the control unit, using model-specific data, as location and wiring vary by model and transmission

How to fix

• Replace the kick-down switch if it is stuck or reads shorted
• Repair or replace damaged wiring and restore insulation where it has chafed
• Clean, repair or replace corroded or loose connectors
• Adjust or repair the pedal or linkage so the switch only operates at full travel
• Repair any throttle position sensor fault found during testing
• Replace or reprogram the control unit only if confirmed faulty, following the manufacturer's procedure

Can I keep driving?

This code for other makes

• P1837BuickKick-Down Switch Failed Short
• P1837CadillacKick-Down Switch Failed Short
• P1837GMKick-Down Switch Failed Short
• P1837GMCKick-Down Switch Failed Short
• P1837OldsmobileKick-Down Switch Failed Short
• P1837OtherTransmission Transfer Case Rear Shaft Speed Sensor Circuit Failure
• P1837SaturnKick-Down Switch Failed Short

Nearby codes

• P1836ChevroletKick-Down Switch Failed Open
• P1842Chevrolet1-2 Shift Solenoid Circuit Low Voltage