P272B - Transmission Range Select Motor Control Circuit Current Too High
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Transmission Range Select Motor Control Circuit Current Too High (P272B). The signal is above the upper threshold, typically from an open circuit, poor connection, or a short to battery voltage.
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Transmission Range Select Motor Control Circuit Current Too High – Coil Resistance | Resistance (Ω) | 3 - 30 Ω (typical) | Connector disconnected at 20°C |
| Transmission Range Select Motor Control Circuit Current Too High – Duty Cycle | PWM (%) | 5 - 95 % (modulates with target) | Engine running, actuator in control |
| Transmission Range Select Motor Control Circuit Current Too High – Supply Voltage | Voltage (V) | 11.8 - 14.4 V | Ignition ON at connector |
Connector disconnected at 20°C
Engine running, actuator in control
Ignition ON at connector
Oscilloscope Waveform Analysis
2 ms/div, 20 V/divPossible Causes
Open circuit on signal wire, spread terminal pin, or short to power feed at Transmission Range Select Motor Control Circuit Current Too High
Chafed or pinched wiring harness along the signal path to Transmission Range Select Motor Control Circuit Current Too High
Internal mechanical wear or carbon deposits inside Transmission Range Select Motor Control Circuit Current Too High
Defective internal output driver or reference circuit in the control module for Transmission Range Select Motor Control Circuit Current Too High
Symptoms
4
Recommended Solution
Measure signal terminal voltage with ignition ON and sensor unplugged to determine if ECM pull-up is active or harness is shorted to 12V.
Verify loaded supply voltage and harness terminal pins at Transmission Range Select Motor Control Circuit Current Too High.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Transmission Range Select Motor Control Circuit Current Too High.
Check supply and the low-side driver at the ECM connector. Replace the actuator or repair the circuit based on the readings.
Mechanic's Tip
Use the scan-tool output test with the scope on the control side at the same time. If duty changes but the actuator does not move, the valve is stuck — not the electrical fault you were chasing.