Lincoln Corsair: Transmission Cooling - 8-Speed Automatic Transmission – 8F35/8F40 / Diagnosis and Testing - Transmission Cooling
Inspection and Verification
-
Verify the customer concern.
-
Visually inspect for obvious signs of mechanical or electrical damage.
-
If an obvious cause for an observed or reported concern is
found, correct the cause (if possible) before proceeding to the next
step
-
If the cause is not visually evident, verify the symptom and refer to the Symptom Chart.
Diagnostic Trouble Code (DTC) Chart
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Diagnostic Trouble Code Chart
Module
|
DTC
|
Description
|
Action
|
TCM
|
P1783:00
|
Transmission Over Temperature Condition: No Sub Type Information
|
GO to Pinpoint Test B
|
TCM
|
P2681:00
|
Engine Coolant Bypass Valve "A" Control Circuit/Open: No Sub Type Information
|
GO to Pinpoint Test A
|
TCM
|
P2682:00
|
Engine Coolant Bypass Valve "A" Control Circuit Low: No Sub Type Information
|
GO to Pinpoint Test A
|
TCM
|
P2683:00
|
Engine Coolant Bypass Valve "A" Control Circuit High: No Sub Type Information
|
GO to Pinpoint Test A
|
Global Customer Symptom Code (GCSC) Chart
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Symptom |
Action |
Start/Run/Move >
Vibration >
Moving/Driving >
Always |
GO to Pinpoint Test D |
Start/Run/Move >
Vibration >
Moving/Driving >
Intermittent |
GO to Pinpoint Test D |
Symptom Chart — Transmission Cooling
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices.
REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
Refer to the DTC Chart before using the Symptom Chart.
Symptom
|
Action
|
Transmission overheating
|
GO to Pinpoint Test C
|
Vibration-a high frequency (20-80 Hz) that is felt through the seat. Changes with engine speed.
|
GO to Pinpoint Test D
|
Assembly gel present in new or low mileage transmissions
|
GO to Pinpoint Test E
|
Check Transmission Fluid Level and Condition
NOTICE:
The vehicle should not be driven if the transmission fluid
level indicator shows the transmission fluid below the minimum
transmission fluid level mark or internal failure could result.
If
the vehicle has been operated for an extended period of time: at
highway speeds, in city traffic, in hot weather or while pulling a
trailer, the transmission fluid may need to cool down to obtain an
accurate reading.
The
transmission fluid level reading on the transmission fluid level
indicator will differ depending on operating and ambient temperatures.
The correct reading should be within the normal operating temperature
range.
Transmission Fluid Level Check
To check the transmission fluid level,
REFER to: Transmission
Fluid Level Check (307-01A Automatic Transmission - 8-Speed Automatic
Transmission – 8F35/8F40, General Procedures).
High Transmission Fluid Level
A
transmission fluid level that is too high may cause the transmission
fluid to become aerated due to the churning action of the rotating
internal parts. This will cause erratic control pressure, foaming, loss
of transmission fluid from the vent tube and possible transmission
malfunction and/or damage. If an overfill reading is indicated,
REFER
to: Transmission Fluid Level Check (307-01A Automatic Transmission -
8-Speed Automatic Transmission – 8F35/8F40, General Procedures).
Low Transmission Fluid Level
A
low transmission fluid level could result in poor transmission
engagement, slipping, malfunction and/or damage. This could also
indicate a leak in one of the transmission seals or gaskets.
Transmission Fluid Condition Check
-
Check the transmission fluid level,
REFER to: Transmission Fluid
Level Check (307-01A Automatic Transmission - 8-Speed Automatic
Transmission – 8F35/8F40, General Procedures).
-
Hold the transmission fluid level indicator over a white
facial tissue and allow the transmission fluid to drip onto the facial
tissue and examine the stain.
-
If evidence of solid material is found, the transmission fluid pan should be removed for further inspection.
-
If transmission fluid contamination or transmission
failure is confirmed by the sediment in the bottom of the transmission
fluid pan, repair the transmission and clean the transmission fluid
cooler tubes and the transmission fluid cooler.
-
If the transmission is to be overhauled or if installing
a new transmission, the transmission fluid cooler must be backflushed.
REFER to: Transmission Fluid Cooler - Backflushing and Cleaning
(307-02A Transmission Cooling - 8-Speed Automatic Transmission –
8F35/8F40, General Procedures).
Pinpoint Tests
![](images/diagnosis_and_testing_transmission_cooling-2589/2091/CaretRight_049.jpg)
PINPOINT TEST A: TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE
Refer to Wiring Diagrams Cell 22 for schematic and connector information.
Normal Operation and Fault Conditions
The PCM receives input from the TFT sensor and determines if the
transmission fluid heater coolant control valve should be open or closed
depending on TFT . The PCM provides a ground to energize the valve as
required by transmission fluid conditions.
DTC Fault Trigger Conditions
DTC |
Description |
Fault Trigger Condition |
TCM P2681:00 |
Engine Coolant Bypass Valve 'A' Control Circuit/Open: No Sub Type Information |
Sets in continuous memory in the PCM if an open is detected in the engine coolant bypass valve circuit.
|
TCM P2682:00 |
Engine Coolant Bypass Valve 'A' Control Circuit Low: No Sub Type Information |
Sets in continuous memory in the PCM if high resistance is found in the engine coolant bypass valve circuit.
|
TCM P2683:00 |
Engine Coolant Bypass Valve 'A' Control Circuit High: No Sub Type Information |
Sets in continuous memory in the PCM if a short to ground is detected in the engine coolant bypass valve circuit.
|
Possible Sources
- Transmission fluid heater coolant control valve circuitry
- Transmission fluid heater coolant control valve
-
PCM
|
A1 RETRIEVE AND RECORD ALL DTCS |
-
Using the diagnostic scan tool, retrieve all DTCs.
Was DTC P2681 or P2683 set?
No |
The issue may not be the Transmission Fluid Heater
Coolant Control Valve electrical system. REFER to symptom chart.
|
|
A2 CHECK BJB (BATTERY JUNCTION BOX)
FUSE 8 (15A) |
Is the resistance less than 5 ohms?
|
A3 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE POWER CIRCUIT FOR A SHORT TO GROUND |
-
Disconnect Transmission Fluid Heater Coolant Control Valve C1915
.
-
Inspect for damaged or pushed-out terminals.
-
Measure.
Click to display connectors
Positive Lead
|
Measurement / Action
|
Negative Lead
|
C1915-1
|
|
Ground
|
Is the resistance greater than 10,000 ohms?
|
A4 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE POWER CIRCUIT FOR AN OPEN |
-
Disconnect Transmission Fluid Heater Coolant Control Valve C1915
.
-
Measure.
Click to display connectors
Positive Lead
|
Measurement / Action
|
Negative Lead
|
C1915-1
|
|
Ground
|
Is voltage greater than 10 volts?
|
A5 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE CONTROL CIRCUIT FOR A SHORT TO GROUND |
-
Measure.
Click to display connectors
Positive Lead
|
Measurement / Action
|
Negative Lead
|
C1915-2
|
|
Ground
|
Is the resistance greater than 10,000 ohms?
|
A6 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE CONTROL CIRCUIT FOR AN OPEN |
-
Measure.
Click to display connectors
Positive Lead
|
Measurement / Action
|
Negative Lead
|
C1915-2
|
|
C1551B-70
|
Is the resistance less than 5 ohms?
|
A7 CHECK THE TRANSMISSION FLUID HEATER COOLANT CONTROL VALVE |
NOTE:
The resistance specification below is for a temperature range between -40°C - 200°C (-40°F - 392°F)
-
Measure.
Click to display connectors
Positive Lead
|
Measurement / Action
|
Negative Lead
|
C1915-1
|
|
C1915-2
|
Is the resistance between 15 - 25 ohms?
Yes |
VIN required to access Guided Routine (PCM)
|
No |
INSTALL a new Transmission Fluid Heater Coolant Control Valve. REFER
to: Transmission Cooling (307-02A Transmission Cooling - 8-Speed
Automatic Transmission – 8F35/8F40, Diagnosis and Testing).
|
|
![](images/diagnosis_and_testing_transmission_cooling-2589/2091/CaretRight_049.jpg)
PINPOINT TEST B: P1783
Normal Operation and Fault Conditions
The PCM receives inputs from the TFT sensor. The PCM uses this
information to determine if the transmission is within normal operating
temperature.
DTC Fault Trigger Conditions
DTC |
Description |
Fault Trigger Condition |
TCM P1783:00 |
Transmission Overtemperature Condition: No Sub Type Information |
Sets in continuous memory in the PCM if a transmission overheating condition exists.
|
Possible Sources
- Transmission overheating condition
|
B1 RETRIEVE AND RECORD ALL DTCS |
-
Using the diagnostic scan tool, retrieve all DTCs.
Was DTC P2681, P2682 or P2683 set?
Yes |
GO to Pinpoint Test A
|
|
![](images/diagnosis_and_testing_transmission_cooling-2589/2091/CaretRight_049.jpg)
PINPOINT TEST C: TRANSMISSION OVERHEATING
Normal Operation and Fault Conditions
The PCM receives input from the TFT sensor and determines an overheating condition exists.
Restricted or damaged transmission fluid cooler.
-
Check for damage or restriction. REFER to: Transmission Fluid Warmer
(307-02A Transmission Cooling - 8-Speed Automatic Transmission –
8F35/8F40, Removal and Installation).
Restricted or damaged transmission fluid cooler tubes.
-
Check for damage or restriction. REFER to: Transmission Fluid Cooler
Tubes (307-02A Transmission Cooling - 8-Speed Automatic Transmission –
8F35/8F40, Removal and Installation).
Maximum towing limits of vehicle have been exceeded.
-
Advise customer of recommended towing limits for vehicle.
Transmission cooling system leaks.
-
Check the transmission cooling system for leaks and SERVICE as required.
Internal transmission concerns.
-
Check for internal transmission concerns causing the overheating
condition. REFER to: Diagnosis By Symptom (307-01A Automatic
Transmission - 8-Speed Automatic Transmission – 8F35/8F40, Diagnosis and
Testing).
Possible Sources
- Clogged transmission fluid cooler or transmission fluid cooler tubes
- Bent or crushed transmission fluid cooler tubes
- Vehicle has been towing a trailer exceeding the maximum towing limits of the vehicle
- Transmission fluid warmer coolant control valve is sticking
- System leaks
- Internal transmission concerns
|
Diagnostic steps are not provided for this symptom or
DTC. REFER to: Diagnostic Methods (100-00 General
Information, Description and Operation). |
![](images/diagnosis_and_testing_transmission_cooling-2589/2091/CaretRight_049.jpg)
PINPOINT TEST D: VIBRATION
Normal Operation and Fault Conditions
A high frequency (20-80 Hz) that is felt through the seat.
-
Check the transmission fluid cooler tubes for the correct routing.
REFER to: Transmission Fluid Cooler Tubes (307-02A Transmission Cooling -
8-Speed Automatic Transmission – 8F35/8F40, Removal and Installation).
Possible Sources
- Transmission fluid cooler tubes grounded.
|
Diagnostic steps are not provided for this symptom or
DTC. REFER to: Diagnostic Methods (100-00 General
Information, Description and Operation). |
![](images/diagnosis_and_testing_transmission_cooling-2589/2091/CaretRight_049.jpg)
PINPOINT TEST E: ASSEMBLY GEL PRESENT IN NEW OR LOW MILEAGE TRANSMISSIONS
Normal Operation and Fault Conditions
-
Assembly gel present in transmission cooler case ports and/or main control assembly on new or low mileage transmissions
-
A clear gel-like grease is injected into
the transmission case cooler ports before the transmission is shipped
from the assembly plant. If enough grease is injected, it may be pushed
back into the main control. The grease acts as a plug to prevent leaks
during transmission installation into the vehicle. Grease found in the
cooler ports and/or main control in new transmission assemblies is
normal and has no affect on performance. As the transmission gets up to
operating temperature, the grease will melt and dissolve into the
transmission fluid.
Possible Sources
|
Diagnostic steps are not provided for this symptom or
DTC. REFER to: Diagnostic Methods (100-00 General
Information, Description and Operation). |
Transmission Cooling
This
vehicle is equipped with an external transmission fluid cooler. The
transmission fluid cooler is an oil-to-coolant fluid cooler which is
mounted to the lower LH side of the
transmission...
Special Tool(s) /
General Equipment
Transmission Cooling System Heated Flusher
Materials
Name
Specification
Motorcraft® MERCON® ULV Automatic Transmission FluidXT-12-QULV
WSS-M2C949-A, MERCON® ULV
Flushing
NOTE:
The cooler bypass valve cannot be backflushed...
Other information:
The power door lock is on the driver and
front passenger door panels.
Unlock.
Lock.
Door Lock Indicator
An LED on each door window trim lights
when you lock the door. It remains on for up
to five minutes after you switch the ignition
off.
Switch Inhibitor
When you electronically lock your vehicle,
the power door lock and interior luggage
compartment release switch will no longer
operat..
Removal
WARNING:
The following procedure prescribes critical repair steps
required for correct restraint system operation during a crash. Follow
all notes and steps carefully. Failure to follow step instructions may
result in incorrect operation of the restraint system and increases the
risk of serious personal injury or death in a crash.
NOTE:
Removal steps in this procedure ..