P0948 — Hydraulic Pump Relay Circuit High

Hydraulic-pump relay circuit: The electrical input is above its permitted range. This is an electrical finding, not an instruction to replace the monitored component. 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: P0948-00, P094800, PO948 (some scan tools add the fault-type byte, e.g. -00).