S | Technical Service Bulletin

Technical Service Bulletin: TSB210032 Released Date: 06-Nov-2023

Intake Air Heater Stuck Relay and Intake Air Heater Damage: Fault Code 383, 1654,
1655, 1656, 1657, 1658, 1659,1718, 5895, 5896, 5897, 5898, 5899, 5911, or 5914

Intake Air Heater Stuck Relay and Intake Air Heater
Damage: Fault Code 383, 1654, 1655, 1656, 1657,
1658, 1659,1718, 5895, 5896, 5897, 5898, 5899,
5911, or 5914

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.

Information Only - OEM Related Matter Not Covered By Cummins® - Contact Appropriate OEM
Dealer or OEM Representative For Additional Information

Contents
Product Affected

¢ ISB6.7 CM2350 B101
¢ B6.7 CM2350 B121B
¢ B6.7 CM2450 B155B

Issue
Symptom:

¢ Hard Start / Long Crank Time
¢ Fault Codes:
° 383

1654

1655

1656

1657

1658

1659

1718

© © © © © © oO

o 5895
° 5896
o 5897
° 5898
o 5899
o 5911
o 5914

Root Cause:

e Intake air heater relay stuck closed leading to extended on-time of the heater. Units
experiencing Fault Code 383 may have experienced extended on-time of the intake air heater
with no air flow entering the system caused by a stuck relay, causing the air heater to
overheat. The isolated power connection bar may expand and lift from the top surface of the
intake manifold cover due to extended on-time (Figure 2). The isolated power connection bar
may also become loose. The issue may progress and exhibit electrical arcing damage to the
intake air heater internal joints (Figure 1), with potential for arcing to cause debris to drop into
the intake system.

Verification

¢ Inspect the insulated power connection bar for deformation. See Figure 2 below. Removal of
the intake manifold cover is not necessary to inspect the insulated power connection bar.
¢ Check if the intake air heater power terminal can be moved by hand. See Figure 3 below.

Figure 1, Example of Arcing Damage on Internal Joints of Intake Air Heater.

Figure 2, Example: (1) View of Power Bar with no Deformation from the Top Surface of Intake
Manifold Cover. Example: (2) View of Power Bar Deformation from Top Surface of Intake
Manifold Cover.

Figure 3, Any Movement of The Terminal Back and Forth As Shown is Unacceptable.

Resolution

e Intake air heater damage that exhibits power connection bar deformation or movement of the
terminal back and forth is due to intake air heater relay failure and is not covered under
Cummins ® warranty. Repair locations are to contact the OEM for further repair direction.

¢ For Navistar® and IC Bus applications reference iKnow article IK1201457 for reviewing grid
heater relay recommended orientation.

¢ Inspect intake ports for debris from grid heater arcing damage. See corresponding Service
Manual. Reference Procedure 010-023 in Section 10.

¢ If misfire fault code is active, inspect the cylinder for damage.

Document History

Date Details
2021-2-11 Module Created
2021-2-17 Corrected Product Affected.
2021-4-5 Updated Verification and Resolution sections. Updated Figure 2.
2021-5-20 Added reference to iKnow article IK1201457.