Powertrain, generic (extended)

P28E9 Shift Motor Position Sensor Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P28E9 is stored when the signal of the shift motor position sensor sits below its valid band. Typical causes are a signal line shorted to ground, a sensor supply that has collapsed, for instance because another sensor on the same feed is shorted, or a failed sensor. No manufacturer documents P28E9 publicly; Kia documents the high counterpart P28E8 on the EV9. In a Denso patent the sensor sits on the detent plate and sends two independent signals, which lets the controller spot a single failed channel; Hyundai's bulletin 22-AT-001H gives the rule of thumb that both position sensor readings sum to about 100 percent, a quick check on the scan tool. Per CARB, inputs like this must be checked for out-of-range values. The actuator usually stays where it is and range changes are blocked.

Likely causes

Sensor signal wire shorted to ground
Sensor supply missing or pulled down
Position sensor failed with output stuck low

Symptoms

  • Shift system warning in the cluster
  • Range changes blocked or gear display wrong
  • Engine or drive system may not start

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–3 h

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

Parts involved

shift motorshift motor position sensortcm

Related codes

P28E7P28E8P28EA

References: law.cornell.edu, patents.google.com, static.nhtsa.gov.