P0947 — Hydraulic Pump Relay Circuit Low

P0947: Hydraulic Pump Relay Circuit Low — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Hydraulic-pump relay circuit: The electrical input is below its permitted range. This signal-level finding does not by itself establish a mechanical failure. The relay-control circuit and the pump hydraulic output are different. A relay DTC does not prove a seized pump or authorize bypassing its control circuit.

Affected system: Transmission hydraulic sensing and pressure unit

Symptoms

  • Warning light may illuminate
  • Related system function may be impaired
  • Vehicle-specific symptoms vary

Possible causes

  • Low or unstable supply voltage, fuse or relay fault, poor ground, or wiring damage
  • Related wiring, connector, power or ground fault
  • Vehicle-specific mechanical or control issue

What to check

  • Record stored and pending codes and freeze-frame data
  • Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
  • Confirm measured values against the vehicle service information
  • Retest under the conditions that set the code
  • Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
  • Repair the verified cause and confirm the code does not return

Also written as: P0947-00, P094700, PO947 (some scan tools add the fault-type byte, e.g. -00).