Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P0779 — Fluid temperature measurement system intermittent transmission

P0779 — Fluid temperature measurement system intermittent transmission

Detailed page for trouble code P0779.

34,332codes
59brands
11,841generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P0779

LAND ROVER P — Powertrain

Fluid temperature measurement system intermittent transmission

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Corroded, loose or damaged connector at the transmission fluid temperature sensor
  • Wiring harness damage (short to power/ground or open circuit) or intermittent break
  • Faulty transmission fluid temperature (TFT) sensor (thermistor)
  • Poor or intermittent ground or reference voltage to the sensor
  • Intermittent fault or software issue in the Transmission Control Module (TCM)
  • Water intrusion or contamination at sensor/connector

Symptoms

  • MIL/Check Engine or transmission light illuminated
  • Stored P0779 intermittent fault
  • Erratic shift behavior or temporary limp-home symptoms during fault occurrence
  • Incorrect transmission temperature value in scan tool or fluctuating readings
  • Possible extended warm-up shifting or shift quality complaints

What to check

  • Read and record codes and freeze-frame data with a capable scan tool (TCM data).
  • Monitor live TFT sensor data while key on/engine running and during a short road test.
  • Visually inspect sensor connector and wiring for corrosion, damage, or water ingress.
  • Perform a wiggle test on harness/connectors while monitoring live data to reproduce the intermittent reading.
  • Backprobe connector and verify reference voltage, signal voltage, and ground at key-on and during operation.
  • Measure sensor resistance at the sensor (cold and warmed) and compare to OEM spec or resistance/temperature chart.

Signal parameters

  • Sensor type: typically a thermistor (temperature-dependent resistor) feeding the TCM.
  • Signal behavior: resistance changes with temperature (most are NTC — resistance falls as temperature rises).
  • Typical signal interface: low-voltage signal to TCM (commonly 0.1–5.0 V range); specific voltages/resistances vary by model — consult OEM spec.
  • Expected behavior: smooth, steady change in reported temperature with heating/cooling; no rapid jumps or dropouts.

Diagnostic algorithm

  1. Connect a dealer-level or advanced scan tool. Record freeze frame and monitor TFT sensor live data and any related transmission parameters.
  2. Clear codes and attempt to reproduce. If code returns intermittently, note the conditions (temperature, vibration, steering, gear selection).
  3. Visually inspect the TFT sensor connector and harness at the transmission for corrosion, broken wires, or evidence of water ingress. Repair any obvious damage.
  4. Backprobe the sensor connector. With key on, verify reference voltage (if applicable), signal voltage, and ground continuity to the TCM. Compare to OEM values.
  5. Measure sensor resistance at the sensor body at ambient and after warming (engine idle or warm fluid). Compare to the OEM resistance vs temperature chart. Replace sensor if out of spec or open/shorted.
  6. Perform a wiggle/stress test on the harness and connectors while monitoring live data to try to reproduce the intermittent fault. Repair broken wires, reseal connectors, or replace harness sections as needed.
  7. If wiring and sensor are good, check continuity between sensor connector and TCM pins. If intermittent or high resistance is found, repair wiring/grounds.
  8. If wiring and sensor check good and intermittent persists, check for TCM software updates/TSBs. Consider TCM input diagnostics or replacement only after exhausting wiring and sensor repairs.
  9. After repairs, clear codes and perform a full drive cycle to confirm the fault is resolved and monitor for recurrence.

Likely causes

  • Corroded/loose sensor connector or bent pins
  • Chafed harness causing intermittent continuity when engine/transmission moves
  • Failed TFT sensor (open or erratic thermistor behavior)

Fault status

⚠️ Status
Intermittent/erratic signal detected from the transmission fluid temperature sensor circuit. The TCM logged P0779 when the temperature signal was unstable or outside expected behavior. Fault may be intermittent and require driving to reproduce.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0115 P0117 P0118 P0715 P0722
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .