2020 Ic Bus Cesb TSBs
124 Technical Service Bulletins across 15 categories
Categories
Engine
43 bulletinsThe purpose of this article is to provide updated repair guidelines for the engine oil pan leak on all 8.8L gasoline and LPG engines.
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Engine oil can leak from the rear of the engine oil pan due to an excessive gap in the sealing area between the engine oil pan and the engine block.
This article only applies to Models w/ 0016UZL Built Between 06/23/2014 05/11/2020 OR Models w/ 0016UZL w/ Safety...
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Recall 14516 Completed Reference the appropriate Technician Manual for models outside of this population. Safety Recall 14516 has been issued for units built before June 23, 2014. For LT and 2018+ LoneStar: If there is a complaint of the bunk blower turning off after an auto start event, the BCM needs to be updated to Data Version 323 or higher. The bunk blower turning off was only present in BCM Data Version 309 to Data Version 322 To properly diagnose the system, you must ensure the recall has been performed. Only the "Cold Loop" sealed refrigerant core PN # 2614669C1 is to be replaced when the refrigerant circuit fails. DO NOT REPLACE THE COMPLETE UNIT IF THE A/C IS NOT FUNCTIONING. Complete unit is not Warrantable Refer to the BASIC TROUBLESHOOTING below before replacing any components. This will help you identify which component is at fault or any electrical issues. Refer to PARTS INFORMATION to properly identify the parts that may require replacement The A/C portion of the system is listed below in the parts section. The 16UZL No-Idle HVAC system is designed to disengage when the engine is started, and can be turned on with the key in any position. This battery-powered no-idle HVAC system provides heating and cooling of the sleeper area without use of the vehicle engine. The system is comprised of the no-idle HVAC components located in the sleeper HVAC module, a separate fuel-operated coolant heater mounted under the sleeper, and four additional batteries housed in a second battery box. The no-idle HVAC system shares the air handling assembly and several major components with the truck's standard HVAC system. Most importantly, the shared evaporator core contains refrigerant circuits for both the no idle system and the truck's standard A/C system. With this configuration, some procedures required to service the no idle A/C system will require opening the refrigerant circuit of the truck's standard A/C system. Trucks equipped with the 16UZL No-Idle HVAC system have two separate HVAC systems (Standard Truck A/C and the MaxxPower unit); it is important to identify each clearly, so you are troubleshooting the correct system. Per the Operator's Manual page 10: Run the heater at least once a month during the year (for a minimum of 15 minutes).
The purpose of this article is to provide updated repair guidelines for the engine oil pan leak on all 8.8L gasoline and LPG engines.
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Engine oil can leak from the rear of the engine oil pan due to an excessive gap in the sealing area between the engine oil pan and the engine block.
This document provides guidance for assessing the feasibility of implementing a customer-requested change to an engine or vehicle parameter/feature.
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Customer requested changes will be approved in accordance with the requirements specified in 40 CFR Part 1037 to ensure continued compliance with greenhouse gas (GHG) regulations.
New CARB Idle Reduction Change Request
Engine replacements for all International engines will need to follow this procedure.
In some geographic areas, ambient temperatures reaching below 15F (-10 C), including high levels of humidity, an...
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operator may experience engine stalling, low performance, and or poor aftertreatment performance. This is caused by condensation accumulating and freezing within the Charge Air Cooler (CAC); affecting air flow into the engine. This article lists all the currently available winter front covers that can be installed on the front grille and bumper to reduce cold air flow to the engine compartment.
This document will guide users through supplemental oil consumption diagnostics for 8.8L PSI gas and propane engines.
The purpose of this article is to provide updated guidance regarding PSI 8.8L repair versus engine replacement.
Title: How to Request a Horsepower Quote Applies To: All International and Cummins Electronic engines
This document will guide a user to replace and reroute Charge Air Cooler (CAC) for vehicles built with the Cummins ISB...
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and B6.7 engines.
This document will guide the user through the exhaust manifold inspection process and cover the change in the exhaust...
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manifold installation procedure to prevent damage due to thermal expansion.
The purpose of this article is to provide updated repair guidelines for the engine oil pan leak on all 8.8L gasoline and...
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LPG.
How to request a horsepower quote; all International and Cummins engines
CE Bus Engine Cover Sealing
Per agreement with EPA and CARB, Cummins, Inc.
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provided an emergency calibration for Cummins ISB, B6.7, ISL9, L9, and X15 engines when a DEF Quality Sensor (DQS) was not available. This action addressed the Diesel Exhaust Fluid (DEF) Quality Sensor failures in the field and the unavailability of parts due to the worldwide chip shortage. This recall is step two of this program designed to revert all affected vehicles back to the certified calibration and to provide them with the latest improved DQS and Coolant Control Valve (CCV) designs. Additionally, the emergency calibration and the restoration to the certified calibration with the latest improved DQS and Coolant Control Valve (CCV) designs have no effect on vehicle Emissions.
Cummins Programming guide and fault codes285 & 265; only vehicles built with Cummins B6.7, X15, or L9 engines
Starter diagnostics and warranty claim procedure for all engines and all chassis EXCLUDING vehicles equipped with PSI...
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engines or Cummins ISB engine with Allison transmissions
QLS Emergency ECM Calibration; only models equipped with Cummins B6.7, X15, L9, or International A26 engines
QLS Emergency Calibration.
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applies to 2016 and newer Cummins B6.6, X15, and L9 engines and all A26 engines
In cold weather, especially during engine warmup, the engine may experience a misfire condition resulting in setting the...
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Malfunction Indicator Lamp (MIL) and possible increase in emissions. Only models with Generation II PSI 8.8L LP engines.
Bus, DuraStar, and MV air compressor inlet hose chaffing/leaking; equipped with Cummins ISB / B6.7 Engines
With the vehicle in motion, the engine control module (ECM) may set a fault code resulting in engine shut down without warning.
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Only models equipped with certain PSI engines
QLS Emergency Calibration; Models equipped with 2016 and newer Cummins B6.7, X15 and L9 engines or International A26...
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engine.
With the vehicle in motion, the engine control module (ECM) may set a fault code resulting in engine shut down without...
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warning; Only models built with PSI gasoline or LPG engines
QLS Emergency Calibration; Models with 2016 Cummins ISX, A26 and EPA 2017 and newer Cummins X15, L9, or B6.7 engines
Engine Oil Capacities.
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All International electronic engines 1994 to present and Cummins ISB, ISM, or ISX engines
DuraStar and MV Air Compressor Inlet Hose Rub.
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Only models equipped with Cummins ISB or B6.7 engines
QLS Emergency Calibration.
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Only models with EPA 2017 and newer Cummins X15, L9, or B6.7 engines
Cummins engine vibration with aftermarket air conditioning installed
Bus with Cummins B6.7 engine and Dual A/C - Cylinder Head Failures
Fuel Filters, Winter Additives, and Blending Fuels for Cummins Engines
CPA RCT (relative compression test) for PSI propane or gasoline V8 8.8L engines; School bus models
Oil Capacities; All Electronic International Engines 1994 - Present.
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Cummins ISB, ISM & ISX
The required Evaporative Emission label may have been printed with an incorrect engine family and/or model year for the...
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engine installed at time of manufacture. Only models with PSI gasoline or propane engines.
Gasoline Engine Bus Fuel System Issues
Voltage gauge drops on cold engine start-up; Only models built with Cummins ISB, B6.7, ISL, or L9 engines
Gasoline Engine Bus Fuel System Issues
Engine Emission Label Replacement, Certificate of Conformance and Clean Idle Sticker Addition Procedure
Gasoline Engine Bus Fuel System Issues
Aggressive Brakes with Air Brake Foot Valve Leak on Bus; only models with feature code 04WEA - Parking Brake Interlock -...
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With Air Brakes Only
Gasoline Engine Bus Fuel System Issues; only models built with PSI 8.8 Gasoline Engine
The brake air line tube from the relay valve port to the left brake modulator valve may be improperly routed resulting...
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in a kinked air line.
Other
26 bulletinsIC Bus Operator's Manuals
This document will guide the user through understanding Prop Shaft Codes and understanding the variations of prop codes.
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(Metric Prop codes start with the number a 4 and Non metric Prop codes start with a 2.)
Title: Driveline Information Center and Troubleshooting Procedures Applies To: All Vehicles
Title: Fan belt replacement guidelines for frayed edges Applies To: All Models
Title: 6090/6091 Connector Damage Applies To: IC Bus Electric CE Series, International eMV Series
J1939 Data Link Source Address Information
Diagnosis of chassis wander complaints.
Luggage rack upholstery repair; only busses equipped with luggage rack.
J1939 Data Link Source Address Information
J1939 Data Link Troubleshooting
Telematics installation guidelines - Only units with 500K data link
J1939 Data link source address information
Pico Scope CCOS (Crankcase Separator Test)
PicoScope Test One Channel RCT
PicoScope Test Resistance and Ohmmeter
PicoScope Test for Datalink (CAN) Health Shorts & opens
J1939 Data Link Source Address Information
J1939 Data Link Troubleshooting
How to obtain As built parameter list
Driveline Information Center and Troubleshooting Procedures
Cleaning and Disinfecting Trucks and Buses
J1939 Data Link Troubleshooting
Cummins ISB Fan Drive Belt Chirp; Cummins ISB and Cummins B6.7
J1939 Data Link Source Address Information
SCR Vehicles Setting DEF Quality Faults due to Crossed DEF Tank Coolant Lines or Inverted DEFTHV
Certain buses may have been built without a CH545 Key (matched key) Vandal Lock as ordered by the customer.
Electrical
11 bulletinsTitle: Next Gen CE Bus Starter Interlock Dash Chime Applies To: Next Gen CE Bus with starter interlock feature built...
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prior to 2/19/25
This document will guide the user through updating the Battery Management System (BMS) calibration.
This document details the procedure that must be followed to ensure proper alternator troubleshooting.
This document covers battery diagnostics, maintenance and storage requirement.
Cummins B6.7 Grid Heater Relay
General Wheel Speed Sensor Troubleshooting
PicoScope Test - Battery Loss of Charge - Parasitic Draw Test
New or replacement body control Module (BC,BCM) not detected; Gen 4 BCM
General wheel speed sensor troubleshooting
Cummins B6.7 Grid Heater Relay
CE Bus Cowl Panel Relay Kit
Infotainment
8 bulletinsThis tool is designed to compare Diamond Logic feature data across multiple vehicle configuration files.
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It allows users to quickly load files either manually or directly from the Diamond Logic Builder Vehicles folder using VIN-based selection. As files are added or removed, the comparison runs automatically with no manual action required. The program presents results in an interactive table that shows feature codes, descriptions, access levels, and whether each feature is present in each selected file. Built-in search, filtering, and sorting make it easy to locate specific features or focus only on differences between files. Column visibility can be customized to show or hide descriptions and access information as needed. Users can remove files individually or clear all files at once, with results updating instantly. The tool also includes reporting and export options that reflect exactly what is visible on screen, allowing results to be printed, copied, saved as text, or exported to CSV for use in Excel or other spreadsheet tools. Overall, the program streamlines the process of comparing vehicle feature configurations, helping users quickly identify differences, validate setups, and document results without manual comparison or external tools.
Title: Radio Clock is Freezing Applies To: Next Gen CE Bus
CE Bus Radio PA not switching to external / internal speakers; only models with feature codes 49CLM or 49CLN
Radio Diagnostics and Information
NEW Ultrasonic DEF Head Unit; All SCR vehicles
NEW Ultrasonic DEF Head Unit available; Only models equipped with SCR Aftertreatment.
NEW Ultrasonic DEF Head Unit; Only vehicles Equipped with SCR
NEW Ultrasonic DEF Head Unit; only models equipped with SCR Aftertreatment
Body & Paint
8 bulletinsThis document will guide the user through repairing a Next Gen CE Bus Driver's Window with loose, displaced, or falling-out upper or lower seals.
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See symptoms below for an example of the issue.
This article addresses chassis lean conditions on all chassis.
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This does not include any diagnostics for body leans such as a cab lean. Keep in mind that a chassis lean may cause or accentuate a cab lean. Filling out the printable form and using the notes in blue will help you to determine the source of the lean and identify the action and parts required to correct the lean.
Aftertreatment Clamp Corrosion; Single Can Aftertreatment Systems
This document will guide the user through determining if there is a sealing issue with the rear emergency door on a CE...
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Bus.
Bus Body Entry Door Switch, LH Panel Mounted
The emergency roof hatch external release handle may break and prevent the hatch release mechanism from being actuated from outside the vehicle.
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However, failure of the external release handle does not prevent actuation of the release mechanism from inside the vehicle.
The emergency roof hatch external release handle may break and prevent the hatch release mechanism from being actuated from outside the vehicle.
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However, failure of the external release handle does not prevent actuation of the release mechanism from inside the vehicle.
Bus Door Adjustment procedure for Electric and Air; only models built 09/15/11 or later
HVAC & Climate
6 bulletinsTitle: A/C Refrigerant and Oil Capacities Applies To: All current models
Title: Servicing Air Conditioning Systems on Electric Vehicles
Title: Factory Installed Air Conditioning, EC4.0 System BE, CE, FE, RE Bus Models
Air Compressor Inlet Hose Chaffing / Leaking
Factory Installed Air Conditioning, EC4.0 System operating instructions and the service manual
Bus Air Conditioning Service Contacts for HVAC Information
Fuel System
5 bulletinsThis document is for Diesel buses MY2020, MY2021, MY2022, MY2023, and MY2024 specifically built between 11/30/20 and...
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5/18/23 that are experiencing fuel leaks at the fuel tank cap for not being seated fully, and for MY2024 and MY2025 buses built between 1/2/24 and 9/19/25 for fuel necks being loose.
This article will guide the reader through steps to help gain a general understanding of the LPG Gen 1 and Gen 2 fuel...
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supply systems, as well as proper fuel system checks to obtain boost pressure.
Bus Diesel fuel Cap Leaks; only models built 11/30/2020 through 05/18/2023
Acceptable Propane Fill Adapter for Refueling
CE Bus fuel sending access hole in wrong location; only models with feature 47AEU built between 5/7/19 and 2/19/20
Brakes
4 bulletinsThis document will guide the user through a step-by-step procedure for detecting water leaks in vehicle cabs and...
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windshields using an ultrasonic sound detector.
This document is to guide users to eliminate brake pedal rattle noise.
The ADB22X caliper on the left (driver side) rear corner on school bus applications may experience an unintended...
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reduction in running clearance during operation, which can lead to a dragging brake. The problem occurs intermittently.
This document will guide the user through diagnosing steering wheels not returning to center on IC CE Buses.
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Only models with feature code 0005708 (tilt column P/N 4095815C91 or 4110141C91), with 0004AZS (air brake ABS with ESP) or 0004JNX (hydraulic brakes), with 0047DNK or 0047DNU or 0047DWC (steering wheel switch).
Transmission
3 bulletinsTitle: Steering Gear Seal Repair Guidelines Applies To: Steering gears
Power Steering Diagnostics Flow / Pressure Specifications For Power Steering Gears and Power Steering Pumps
This article is for adding additional protection to the driver's area of the bus to help mitigate the transmission of...
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germs.
Pre-Delivery & Maintenance
2 bulletinsTitle: Service Portal iKNow Feedback Case Types Applies To: All
Bus seat back foam inspection guidelines
Hybrid & EV
2 bulletinsTitle: Electric Vehicle Air Dryer Operation
ISB 6.7 Frequent Regeneration
Software & Calibration
2 bulletinsQLS Emergency Calibration Revert Process
QLS Emergency Calibration Revert Process
Lighting
2 bulletinsRepair Procedures for Vehicles Struck by Lightning
Bus Strobe Light Replacements
Suspension
1 bulletinSuspension Lean Diagnostics; All models
Tires & Wheels
1 bulletinSuggested alignment target values when performing a vehicle axle alignment