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Title : S13 Integrated Powertrain Known Leak Diagnostics
Applies To : S13 Integrated Powertrain

CHANGE LOG
Please refer to the change log text box below for recent changes to this article:
02/23/2026 - Changes to step 1 of T14 leak section.
02/19/2026 - Removal of manual pathing and additon of GUIDE step instructions
01/12/2026 - Addition of links to the manual sections per truck model.
02/02/2026 - Removal of S13 leak section and migration to manual notes added
01/26/2026 - Addition to Best Practices section for opening a case file. ESN cutoff addition to step





DESCRIPTION
This article is to walk through and assist the technician in diagnosing and repairing some of the known leaks around the S13 Integrated
Powertrain.

SYMPTOM(s)
Diagnostic Trouble Code(s) & Dashboard Indicator Light(s):
DTC/Light
N/A

Description
No Faults or Warning Lights

Customer Observations or Concerns:
Oil Leak
Coolant Leak
Before performing any diagnostics, please note:
S13 Engine: The engine comes with dye in the oil from the factory, which will glow under UV light.
T14 Transmission: The transmission does NOT have dye in the oil.
S13 Fluid Leak Diagnostics
T14 Fluid Leak Diagnostics
Tech Tips & Updated Parts Information

Service Parts Information:

Please consult with the dealer parts department and confirm that the current and updated service part numbers are being used. Parts are being
updated frequently, which may cause dealer stock to be an older part number.

Best Practices:
Oil Detection: If oil is seen, use UV light as a first-pass detection method. Be sure to clean all the oil off using an engine degreaser. After
cleaning, monitor with UV light to identify where the oil leak reappears for proper leak source identification.
Assembly Lube and Fuel: These can also glow under UV light. Be cautious when identifying the type of fluid. If in doubt, clean the area and
monitor for the dye to reappear.
UV Light Tips: If the dye is hard to see, do not add more dye. Instead, try using a different UV light, as each UV light has different
wavelengths that react better or worse to various dyes.
Opening a Tech Service Case File: When opening a case file, the following MUST be provided; tech service will not move on to other
diagnostics or provide repair directions until the required information is provided:
1. Clear images showing the leak source, including an image showing the UV light results highlighting the leak (oil leak specific).
1. See Dyed Oil vs. Non-Dyed Oil vs. Assembly Lube image below.
2. NOTE, if the image quality is not acceptable, to CLEARLY confirm the leak source location, tech service will ask for a better
image. Ensure the image taken is reviewed by the technician and confirmed clear, concise, and acceptable before attaching to the
case file.
2. Complete step-by-step results from this article, including confirmation that the affected leak area was cleaned, and the engine ran to
test the source of the leak.
3. Confirmation of recent repairs related to leaks, what repair was performed, and if the same leak or a new leak has returned.

Dyed Oil vs. Non-Dyed Oil vs. Assembly Lube

Image showing different glow reactions of fluids under UV light.

SPECIAL TOOL(s) / SOFTWARE
Tool Description
UV Light

Tool Number
N/A

Comments

Instructions
Locally Sourced

S13 FLUID LEAK DIAGNOSTIC STEP(s)
The S13 Engine Oil Leak steps have been migrated to GUIDE diagnostics.
Navigate to MSI Service Information by VIN
1. Enter the chassis number
2. Click the "Fault Code Action Plan" button
3. Source Address = 80000
4. Fault Type = CC01224
5. FMI = 0
6. Click "Search"
Image Based Instructions

The S13 Engine Coolant Leak steps have been migrated to the service and Diagnostic Manual "Symptoms" section.
12 - Engine > Engine > International S13 Diesel Engine (2024 GHG) > Symptom Diagnostics > Cooling System > Low Coolant Level /
Coolant Leak
LT/RH - Low Coolant / Coolant Leak
HX - Low Coolant / Coolant Leak
HV - Low Coolant / Coolant Leak

T14 FLUID LEAK DIAGNOSTIC STEP(s)
Step
#1

Front of Transmission

Decision

Inspect the clutch inspection port for signs of oil leaking. Remove the plug if a Yes, oil leak from the engine.
fluid leak is found and verify the fluid identified is oil from the engine or oil

from the transmission. Clean the affected area and re-test for the leak to
confirm the source location:

Perform External Engine Oil Leak GUIDE
session.

Was an oil leak discovered?
NOTE: Before major disassembly, verify whether the fluid leaking is engine or
transmission oil. Keep in mind that if the vehicle has not had an oil change,
Yes, oil leak from the transmission.
the engine oil has dye added from the factory, while the transmission oil does
not. Compare the glow of the oil using a UV light on the dipstick with what is Proceed to step 2.
observed from the leak to determine if the oil is engine oil or transmission oil.

No,
Proceed to step 3.

Step

Front of Transmission

Decision

Remove the transmission for further inspection. Inspect for oil leaking behind Yes.
the front cover of the transmission. See Figure #1 and Figure #2 for examples:
Capture images of the oil leak location.
Was an oil leak discovered?
Open a Powertrain Technical Support
case file. See Best Practices section for
case opening requirements.
If the leak is originating from location 2,
confirm which colored arrow is the source,
and provide an image for review.
#2

No.
Ensure the oil is not leaking from the
engine. Review Step 11 from the S13 Oil
Leak Diagnostic section above.

Figure 1 - Possible Leak Locations Behind the Front Cover

Figure 2 - Location 2 Leak Example

Step
#3

Passenger Side Transmission
Inspect for coolant on the passenger side of the transmission. Coolant can be Yes.
seen seeping through the joints of rubber coolant hoses and at the hard lines
near the transmission cooler area. There are two sections of rubber hose on

Decision

the supply side of the cooler and two sections of rubber hose on the return
side of the cooler. See Figure #3, Figure #4, and Figure #5 for examples:

Reference IK1300194 for repair
instructions.

Was a coolant leak discovered?

No.
Proceed to step 4.

Figure 3 - Transmission Cooler Hose Leak

Figure 4 - Transmission Cooler Hose Leak

Figure 5 - Transmission Cooler Hose Leak

Step

Driver Side & Under The ECA

Decision

Inspect under the transmission on the driver's side. Inspect for oil leaking
Yes.
down the ECA (Electronic Clutch Actuator) and collecting at the bottom of the
transmission. See Figure #6 and Figure #7 for examples:
Proceed to step 5 for further inspection
and repair steps.
Was an oil leak discovered?

#4
No.
Proceed to step 6.

Figure 6 - Oil Leak at the ECA

Figure 7 - Oil Leak at the ECA

Step
#5

ECA Inspection/Repair
Inspection:
Remove the ECA and inspect for wetness at the pointed galley from
Figure #8.
If wetness is observed, remove the main valve body assembly, inspect
the condition of the green O-Ring as called out in Figure #9.
If the O-Ring is in good condition, inspect the 3 air ports at the top for
wetness as shown in Figure #10.
NOTE: There will be oil present in the housing behind the main valve body
assembly; this is normal. The system is designed for shift rails to pass a slight
amount of oil so they self-lubricate, oil that collects in the housing then flows
back into the sump through one of the drilled passages. The galley with the
green o-ring called out in Figure #9 is the same galley behind the ECA as

Decision
Repairs:
Green O-Ring from Figure #9 - 104229N1
Black O-Ring in shift actuators that
position sensors sit in - 105465N1
Green O-Ring on the position sensor
harness connector that sits in the housing
- 104440N1

called out in Figure #8. If the green o-ring is left out, not installed properly, or
gets pinched due to slippage during the installation process, the collected oil
will run down into the ECA area, and this will result in an external transmission
leak.

Figure 8 - ECA Removed

Figure 9 - Main Valve Body Removed

Figure 10 - Air Ports Behind the Main Valve Body

Step

Back of Transmission

Decision

Inspect the rear of the transmission for signs of oil leaking/coating. See Figure Yes, a leak is present with no fault
#11 and Figure #12 for examples. Check the output shaft for excessive play:
present.
Was an oil leak discovered with SPN 191 FMI 2 present?
NOTE: This symptom may be associated with a fault code. If the vehicle has
logged SPN 191 FMI 2, check the output yoke for play, pull the output speed
sensor for inspection and check if there is any metal noticed on the tip of the
sensor. See Figure #13 for an example.

Replace the output flange seal. Reference
the S13 Integrated Powertrain Technician
Manual - "Output Flange and Output
Flange Seal Removal"
Yes, a leak, fault code, excessive play
on the output, and metal on the sensor
is present.

#6
Capture images of the damage found and
then open a technical support case file for
direction. See Best Practices section for
case opening requirements.
No.
Open a technical support case file. See
Best Practices section for case opening
requirements.

Figure 11 - Rear Output Yoke Leak

Figure 12 - Rear Output Yoke Leak

Figure 13 - Output Speed Sensor Metal Debris

Return to top

Tech Tips & Updated Parts Information
The inner gear housing has been updated to remove the upper oil feed dowel-pin bore. This is not required, and the updated parts can
be used without issue. See Figure #1 below for an example.

Figure 1

Item 1: Old-style housing with a dowel hole drilled.
Item 2: New-style housing with no dowel hole drilled.

Return to top

WARRANTY INFORMATION
Warranty Claim Coding:
Refer to the Warranty Coding Manual for Group and Noun Codes.

Standard Repair Time(s):
Refer to the SRT Manual for Repair Times

OTHER RESOURCES
Master Service Information Site

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