Chassis, generic

C00A0 4WD/AWD Rear Differential Unit Actuator B Position Sensor Correlation

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modePossible

C00A0 is the plausibility check across all three position channels of actuator B. Each line may be intact, but the pattern they form is impossible, out of sequence or contradicts the commanded movement, so the controller can no longer trust where the second actuator stands. Woodward lists 000 and 111 as illegal states for 120-degree spacing and 101 or 010 for 60-degree spacing. A Hyundai Kefico patent uses all-zero and all-one readings to tell an open line from a short. Common roots are a shared ground or supply problem, a connector that is not latched, or a magnet that has shifted. Ford reports the sister code C009C for actuator A on the Bronco Sport, but no manufacturer publishes a C00A0 case. GKN notes that its actuator controllers include self-diagnostics.

Likely causes

Shared sensor ground or supply of actuator B faulty

Actuator B connector not fully latched

Rotor magnet or sensor carrier shifted inside actuator B

Symptoms

AWD fault message with rear torque control switched off
Possible loss of related assist functions shown in the cluster

Repair estimate

DifficultyHardWorkshop job

Parts and labour€60–1,200

Time0.3–3 h

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

Parts involved

rear diff actuator b pos arear diff actuator b pos brear diff actuator b pos c

Related codes

C009D C009E C009F C009C C0097

References: patents.google.com, patents.google.com, mobilityengineeringtech.com.