P0791 Toyota Highlander – Intermediate Shaft Speed Sensor “A” Circuit

Toyota-specific code — factory diagnostic data

Last updated: May 31, 2026

Definition source: Toyota factory description. Diagnostic guidance is based on factory-defined fault logic for this code.

P0791 on the 2014 Toyota Highlander means: Intermediate Shaft Speed Sensor "A" Circuit. It is a circuit code reported by the U660e Automatic Transaxle System, Fwd 3.5l [12/2013 – 08/2014].

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P0791 Quick Answer

P0791 on a 2014 Toyota Highlander indicates Intermediate Shaft Speed Sensor "A" Circuit. Start with a freeze-frame check and a careful inspection of the connector and wiring at the affected device before replacing any parts.

What Does P0791 Mean on a Toyota Highlander?

On the 2014 Toyota Highlander, the U660e Automatic Transaxle System, Fwd 3.5l [12/2013 – 08/2014] sets P0791 when it detects a fault matching its official definition: Intermediate Shaft Speed Sensor "A" Circuit. This is a manufacturer-specific definition from Toyota factory diagnostic data and applies to the XU50-generation Highlander.

Symptoms

• Warning light for the affected system (check engine, ABS, airbag, or a system indicator depending on the module)
• Reduced or lost function of the u660e automatic transaxle system, fwd 3.5l [12/2013 – 08/2014]
• Possible related codes from other modules on the Highlander CAN/LIN network

Common Causes

• Fault in the component named in the definition (intermediate shaft speed sensor "a" circuit)
• Open, shorted, or high-resistance wiring in the affected circuit
• Connector corrosion, water ingress, or a backed-out terminal
• Loss of supply voltage or a poor ground at the device
• Module internal fault — confirm wiring and supplies before condemning the module

Diagnostic Approach

For P0791 on the 2014 Toyota Highlander you’ll want an OBD-II scan tool with live-data and freeze-frame support (a Toyota Techstream-class tool reads enhanced data), plus a digital multimeter and the wiring diagram.

• Confirm the code is current, not stored history, and record freeze-frame data.
• Read all modules — related codes often pinpoint the root cause faster than the headline code.
• Inspect and wiggle-test the connector at the named device while watching live data.
• Measure supply voltage and ground integrity at the device; verify the circuit against the Highlander wiring diagram.
• Substitute or isolate the suspect device only after wiring and supplies check out.
• Clear the code and road-test through one or two drive cycles to confirm the repair.

Possible Fixes

• Repair open/short/high-resistance wiring or a corroded connector
• Restore supply voltage or ground at the affected device
• Replace the failed component named in the definition
• Replace and, where required, initialise/program the module if it is internally faulty

Can I Still Drive With P0791?

It depends on the system. U660e Automatic Transaxle System, Fwd 3.5l [12/2013 – 08/2014] faults that affect braking, the airbag/restraint system, power steering, or stability control should be repaired before further driving. Comfort or convenience faults can usually be deferred briefly, but related codes can mask one another on the Highlander network — diagnose promptly.

Source

Code definition from 2014 Toyota Highlander (XU50) factory diagnostic information (U660e Automatic Transaxle System, Fwd 3.5l [12/2013 – 08/2014]). Symptom, cause, and diagnosis guidance summarised from standard OBD-II diagnostic practice for this platform.