P1783 Transmission fluid over-temperature condition on Ford and Mazda automatics

Ford and Mazda P1783 transmission over temperature

Severity not verified — if the car runs badly, have it inspected

The code reports overheated transmission fluid, and owners report burnt fluid and rebuilt transmissions, but we found no source that sets a safe driving limit.

It gets more serious if:

  • Inspect soon: The O/D OFF light blinks, the fluid smells burnt, or the transmission slips or shifts harshly.

Source: how we rate severity

P1783 in short

On Ford and Mazda automatics, P1783 means the transmission fluid ran too hot. A Mazda bulletin links it to long highway drives and a blinking O/D OFF light. Burnt fluid and ruined transmissions are reported, so ease off towing and heavy loads and have the fluid and cooling checked soon.

Ford and Mazda transmissions measure fluid temperature, and the computer stores P1783 when the fluid is hotter than its limit. A reference list shows the same over-temperature meaning for both makes.

Mazda bulletin 05-005/02, as quoted by 626 owners, describes a flashing O/D OFF light and P1783 after extended highway driving, with a cooling kit as the fix. A Ford Explorer owner found black fluid and metal on the magnet after the code.

Not every P1783 is a heat problem: Ford and Mazda bulletins also pair it with cold-climate shift concerns on CD4E transaxles, and a Ford bulletin pairs it with a fluid leak at the converter housing on 2004-2005 Explorers.

Pick your make

P1783 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Overheated fluid from sustained load or poor cooling

    Supported by vehicle data
    Why it ranks here
    Mazda owners quote a bulletin that ties the code to extended highway driving and a cooling kit, and Ford owners found burnt fluid.
    What would change this
    Rises if the fluid is dark or smells burnt, or the cooler lines are restricted. Falls if the fluid is clean and temperature readings look normal.

  2. Code set with cold-climate shift or engagement concerns on a CD4E transaxle

    Supported by vehicle data
    Why it ranks here
    A Ford bulletin for 2001-2005 Escape and a Mazda bulletin for 2001-2005 Tribute pair P1783 with cold-climate shift concerns.
    What would change this
    Rises on a CD4E transaxle that acts up in cold weather. Falls on other transmissions.

  3. Fluid leak at the converter housing (2004-2005 Explorer 5R55S)

    Possible — needs testing
    Why it ranks here
    A Ford bulletin lists the leak and P1783 together on vehicles built before 12/12/2004; the summary does not say which causes which.
    What would change this
    Rises if the fluid level is low and the housing is wet. Falls if there is no leak.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all transmission codes and note whether P0733 is stored with P1783 and what the weather and driving were like.

    Low riskTool: OBD-II scan tool

    • IfThe code set after towing, heavy loads or long highway driving

      It meansSuspect overheated fluid.

      Go to step 2

    • IfThe code set in cold weather with P0733 or shift complaints on an Escape or Tribute

      It meansAsk the dealer about the cold-climate bulletin.

      Go to step 2

  2. Have the fluid level and condition checked, and look for leaks and a restricted cooler or radiator.

    Best left to a shopTool: dipstick or fill port, lift

    Warning:The transmission and exhaust are hot after driving; wait before touching fluid or lines, and a shop should lift the vehicle.

Symptoms

  • Check engine light on
  • O/D OFF light blinking Gets more serious: stop and have it checked.
  • Burnt-smelling fluid, harsh shifts or slipping Gets more serious: stop and have it checked.

How to fix

  1. Avoid towing or heavy loads until the fluid and cooling have been checked.

On your vehicle

Mazda

  • 1998–2001 · 626

    Supported by vehicle data

    626 bulletin 0500502 covers a blinking O/D OFF light with P1783 after extended highway driving; owners report a cooling kit as the fix.

  • 2001–2005 · Tribute

    Supported by vehicle data

    Tribute bulletin 0500504 covers P1783 and P0733 with cold-climate shift concerns.

  • 0500502Status unverified

    O/D OFF light flashing with P1783 after extended highway driving

    1998–2001626 · NHTSA 634465

    Describes the blinking O/D OFF light with P1783 after long highway drives; owners quote a cooling kit as the fix.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 0500504Status unverified

    A/T indicator lamp on with P1783 and/or P0733, or cold-climate shift concerns

    2001–2005tribute · NHTSA 10015682

    Covers the transaxle indicator lamp with these codes and cold-climate shift or engagement concerns.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ford

  • 2001–2005 · Escape

    Supported by vehicle data

    Escape bulletin 04141 covers P1783 and P0733 with cold-climate concerns on the CD4E transaxle.

  • 2004–2005 · Explorer

    Supported by vehicle data

    Explorer bulletin 0527 pairs a converter housing leak with P1783 on early-build 5R55S units.

  • 2002–2020 · Explorer

    Supported by vehicle data

    Explorer owners report burnt or black fluid after P1783 on 2002 and 2020 models.

  • 04141Status unverified

    Transmission indicator lamp with P1783 and/or P0733, cold-climate shift concerns (CD4E)

    2001–2005escape · NHTSA 10009323

    Same cold-climate concern on the CD4E transaxle.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 0527Status unverified

    5R55S converter housing fluid leak and P1783 on vehicles built before 12/12/2004

    2004–2005explorer · NHTSA 10012938

    Pairs a converter housing leak with P1783 on early-build 5R55S Explorers.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0733Transmission computer sees the wrong speed ratio in third gear

    Shares causes Supported by vehicle data

    Ford and Mazda bulletins list P1783 and/or P0733 together on CD4E transaxles.

All Transmission codes

Sources and review

  1. NHTSA complaint 636798: 2002 Mazda 626, P1783 — NHTSA (owner complaint)
  2. NHTSA complaint 577703: 2002 Ford Explorer, P1783 — NHTSA (owner complaint)
  3. NHTSA complaint 2112327: 2020 Ford Explorer, P1783 — NHTSA (owner complaint)
  4. NHTSA complaint 639911: 2001 Mazda 626, P1783 — NHTSA (owner complaint)
  5. Ford bulletin 04141: transmission indicator lamp with P1783 and/or P0733, cold-climate shift concerns, CD4E — Ford Motor Company (via NHTSA flat-file summary)
  6. Mazda bulletin 0500504: A/T indicator lamp on with P1783 and/or P0733, or cold-climate shift and engagement concerns — Mazda North American Operations (via NHTSA flat-file summary)
  7. Ford bulletin 0527: 5R55S fluid leak at the converter housing area, P1783 on vehicles built before 12/12/2004 — Ford Motor Company (via NHTSA flat-file summary)
  8. Mazda bulletin 0500502: O/D OFF light flashing with P1783 after extended highway driving — Mazda North American Operations (via NHTSA flat-file summary)
  9. NHTSA complaint 698214: 1998 Mazda 626, P1783 — NHTSA (owner complaint)
  10. P1783 manufacturer-specific definitions — TroubleCodes.net (BAT Auto)
Last reviewed
Written by
Saurabh K.
Editorial review
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This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

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