P0837

Four Wheel Drive (4WD) Switch Circuit Range/Performance

Severity: Medium
Driving: Drivable — book it in

The four-wheel drive switch is answering but its reading is not plausible - two positions reading the same, or a position reported that the selector is not in. Usually this is worn switch contacts or a linkage that is not moving the switch fully rather than an outright failure.

Possible causes

CommonWorn switch contacts giving an ambiguous position
CommonSwitch out of adjustment or its linkage worn
CommonCorroded connector
PossibleActuator not completing its travel
PossibleWiring fault causing a partial short between circuits

What you might notice

Drive mode indicator flickering or wrong
Four-wheel drive engaging when not requested, or not engaging
Mode changes taking a long time
Check engine light on

What to check, in order

Move the selector slowly through every position while watching the reported state. Look for a position that is briefly ambiguous - the classic sign of worn contacts.
Check the switch adjustment and its linkage for wear.
Inspect the connector for corrosion and for a partial short between adjacent pins.
Confirm the actuator completes its travel.
Check for transfer case codes alongside.

Read this code from your own car

Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.

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Where this code sits

B · Body C · Chassis P · Powertrain U · Network and communication