P0948 Hydraulic Pump Relay Circuit High

P0948 indicates a high hydraulic pump relay circuit. The relay control or output path is open, shorted to voltage, or above expected range.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Transmission
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not bypass the pump relay; diagnose the high circuit because uncontrolled pump operation can damage the system.

Useful checks before replacing parts

Check relay control voltage, relay output, ground integrity, open circuits, short-to-voltage faults, socket condition, and driver state.
Inspect relay contacts, fuse block terminals, pump connector, harness routing, water intrusion, and wiring disturbed during service.
Compare relay command with pump current and pressure rise to confirm whether the high circuit prevents pump operation.

Related OBD-II codes

These nearby transmission entries can help compare wording and fault area. They may share the same verification status as the source database.