T-SB-0135-19

T-SB-0135-19
September 26, 2019
Low Coolant, MIL ON DTC P148F00, and/or Poor Heater
Performance
Service
Category
Engine/Hybrid System
Section
Cooling
Market USA
Applicability
YEAR(S)
MODEL(S)
2017 - 2019
Prius Prime
2016 - 2019
Prius
ADDITIONAL INFORMATION
Introduction
Some 2016 – 2019 model year Prius and 2017 – 2019 model year Prius Prime vehicles may
exhibit one or more of the following conditions due to a coolant leakage at the front exhaust pipe
heat exchanger:

Low coolant level

MIL ON accompanied by Diagnostic Trouble Code (DTC) P148F00
 Poor heater performance
The front exhaust pipe with heat exchanger assembly has been updated. Follow the Repair
Procedure in this bulletin to address this condition.
Warranty Information
OP CODE
DESCRIPTION
TIME
OFP
T1
T2
170171P
R & R Front Exhaust Pipe Assembly
1.5
17410-37B52
17410-37B50
17410-37A00
64
12
APPLICABLE WARRANTY
 This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect
for 96 months or 80,000 miles, whichever occurs first, from the vehicle’s in-service date.
 Warranty application is limited to occurrence of the specified condition described in
this bulletin.
 For 2016 and 2017 model year Prius and 2017 – 2019 model year Prius Prime vehicles, sold,
registered, and normally operated in California, Connecticut, Maine, Maryland, Massachusetts,
New Jersey, New York, Oregon, Rhode Island, and Vermont. The California Emissions Defect
and Performance Warranty coverage is 180 months from the date of first use or 150,000 miles
(whichever occurs first).
© 2019 Toyota Motor Sales, USA
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Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance
Parts Information
PART NUMBER
PREVIOUS
PART NAME
QTY
Pipe Assy, Exhaust, Front
1
Gasket, Exhaust Pipe
1
SUPPLIER
QTY
NEW
17410-37B52
17410-37B50
17410-37D40
17410-37A00
17451-0D140
17451-F2010
Required Tools & Equipment
REQUIRED EQUIPMENT
Techstream ADVi*
TSADVUNIT
Techstream 2.0
Techstream Lite
PART NUMBER
TS2UNIT
ADE
Techstream Lite (Green Cable)
TSLITEPDLR01
TSLP2DLR01
*Essential SST.
NOTE
 Only ONE of the Techstream units listed above is required.
 Software version 14.20.019 or later is required.
 Additional Techstream units may be ordered by calling Approved Dealer Equipment (ADE)
at 1-800-368-6787.
© 2019 Toyota Motor Sales, USA
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Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance
Repair Procedure
1. Is the vehicle exhibiting ANY of the following conditions?

Low coolant level (or coolant was recently added to address a low-level condition)

MIL ON accompanied by DTC P148F00

Poor heater performance

YES — Continue to step 2.

NO — This bulletin does NOT apply. Continue diagnosis using the applicable
Repair Manual procedure.
2. Inspect for signs of coolant leakage into the exhaust system from the front exhaust
pipe heat exchanger.
CAUTION
 Do NOT remove the reserve tank cap and air release valve while the engine or radiator
assembly are still hot. Pressurized, hot engine coolant and steam may be released and
cause serious burns.
Refer to TIS, applicable model and model year Repair Manual:
 2016 / 2017 / 2018 / 2019 Prius:
Engine/Hybrid System – Cooling – “2ZR-FXE (Cooling): Cooling System:
On-Vehicle Inspection”

2017 / 2018 / 2019 Prius Prime:
Engine/Hybrid System – Cooling – “2ZR-FXE (Cooling): Cooling System:
On-Vehicle Inspection”
 To prevent burns, do NOT touch the engine, exhaust pipe, or other high temperature
components while the engine is hot.
Refer to TIS, applicable model and model year Repair Manual:
 2016 / 2017 / 2018 / 2019 Prius:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Removal”

2017 / 2018 / 2019 Prius Prime:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Removal”
A. When the engine and exhaust system are cold, and the engine is OFF; unbolt and
disconnect the rear exhaust pipe assembly from the front exhaust pipe assembly at the
mating flange.
© 2019 Toyota Motor Sales, USA
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Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance
Repair Procedure (continued)
B. Perform a visual inspection inside the exhaust pipe for signs of coolant leakage into
the exhaust system.
C. If no visible signs of leakage are found during the initial inspection, pressurize the cooling
system to 122 kPa (1.2 kgf/cm2, 17 psi), and recheck for visible signs of leakage into the
exhaust from the heat exchanger.
HINT
Inserting a borescope into the front exhaust pipe may aid in leak identification.
3. Was ANY leakage found?

YES — Continue to step 4.

NO — This bulletin does NOT apply. Reassemble the vehicle using a NEW exhaust pipe
gasket and continue diagnosis using the applicable Repair Manual procedures.
4. Remove the front exhaust pipe assembly.
Refer to TIS, applicable model and model year Repair Manual:

2016 / 2017 / 2018 / 2019 Prius:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Removal”

2017 / 2018 / 2019 Prius Prime:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Removal”
5. Install the NEW front exhaust pipe assembly.
Refer to TIS, applicable model and model year Repair Manual:

2016 / 2017 / 2018 / 2019 Prius:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Installation”

2017 / 2018 / 2019 Prius Prime:
Engine/Hybrid System – Intake/Exhaust – “2ZR-FXE (Intake / Exhaust):
Exhaust Pipe: Installation”
© 2019 Toyota Motor Sales, USA
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Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance
Repair Procedure (continued)
6. Using Techstream, clear ANY stored DTCs.
7. Perform Health Check to confirm if ANY DTCs remain.
Are ANY DTCs present?

YES — Continue diagnosis using the applicable Repair Manual procedure.

NO — Start the engine and warm it up to normal operating temperature. Then, test-drive
to confirm proper vehicle operation.
© 2019 Toyota Motor Sales, USA