Powertrain, generic · Transmission

P0959 Auto Shift Manual Mode Circuit Intermittent

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The signal reporting the selector lever in the manual gate drops out or toggles briefly while the lever is not moved, so the transmission control switches between manual and automatic mode on its own. The voltage is not stuck out of range as with P0957 or P0958 but jumps. Loose connector pins at the lever, a harness that flexes with the shifter or a worn microswitch are typical. A Hyundai patent shows such a microswitch actuated by the lever's sideways movement, a Nissan patent the two-contact mode switch. No manufacturer documents this exact code publicly; CARB requires circuit checks. P0955 is the general fault, P0954 the intermittent fault of the up/down circuit.

Likely causes

Loose pins in the selector lever connector
Worn or bouncing mode microswitch
Harness damaged where it moves with the lever

Symptoms

  • Manual mode switches on or off by itself
  • Gear display flickers between D and manual gear
  • Fault often appears on rough roads

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–600
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

auto shift manual switchwiring harnesstcm

Related codes

P0955P0956P0957P0958P0954

References: law.cornell.edu, patents.google.com, patents.google.com.