S | Technical Service Bulletin

Technical Service Bulletin: TSB240057 Released Date: 20-Mar-2024
HGJAx New Inlet Cover Design for Cooling Improvement

HGJAx New Inlet Cover Design for Cooling
Improvement

Warranty Statement

The information in this document has no effect on present warranty coverage or repair practices, nor
does it authorize TRP or Campaign actions.

Contents

Product Affected

¢ HGJAA Specs A-M
e HGJAB Specs A-M
e HGJAC Specs A-M
¢ HGJAD Specs A-M
e HGJAE Specs A-M
e HGJAF Specs A-M
¢ HGJAG Specs A-M

Issue Summary
Symptom

¢ Generator sets exhibit high operating temperatures which can lead to nuisance shutdown
events.
e Fault Code 36 (FC 36) — Generator Set Stopped Without Fault Condition.

Root Cause

¢ Hot air recirculation: The generator set draws all the cooling air in and out of the bottom. As
such, the cool air intake and hot air discharge are very close to each other. Care must be
taken with all installations to make certain that the hot air flowing out is not drawn into the cool
air intake. An air recirculation test is required for every unique installation.

Verification

If generator set is experiencing heat related issues,

1. Test drive the vehicle with the generator set on and make sure it does not shut down with FC
36.

a. If it does, complete the troubleshooting steps for FC 36 laid out in service manual

A035D011.
2. Perform hot air recirculation test and refer to product service manual A035D011 for detailed
instructions on performing the test.

a. If it passes, implement the resolution steps below.

b. If it does not, implement the resolution steps below and follow product installation quality
guidelines. (Refer to TSB 180078 for HGJAx Ducting Kits and Carburetor Insulation;
Countermeasures for FC 36 Shutdowns Due to Hot Air Recirculation).

Resolution

The new inlet cover design Part Number A071V009 is backwards compatible and was created to
reduce HGJAx operating temperatures. The new inlet cover will:

1. Add louvers to fan guard on bottom of generator set.
2. Increase generator set cooling air flow.

3. Have updated floor mount cutout for cooling benefit per generator set mounting Part Number
A074L374.

17102141

Figure 1, Old Production Inlet Cover Part Number 0134-5232 on the left and New Inlet Cover
Part Number A071V009 on the right

Reason for Change

This document informs the field of the release of a new inlet cover for cooling improvement. This
design change was implemented to reduce generator set operating temperatures.

Customer Communication

This upgrade is not supported by Cummins or any coach manufacturer. It is entirely an elective
repair that can correct generator sets on coaches that have problems with high operating
temperatures.

Service Instructions
If your unit is experiencing high operating temperatures:

1. Refer to product service manual for troubleshooting steps to check all possible causes of FC
36.
2. Replace old air inlet cover with Part Number A071V009.

Service Parts