Technical Service Bulletin
Technical Service Bulletin: TSB220228
Released Date: 05-May-2023
HDZAA Injection Pump (UCV) Contamination Issue

HDZAA Injection Pump (UCV) Contamination Issue
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
HDZAA Spec F

Issue
Symptom:
Customer complaint of no start.
Root Cause:
Contaminants in the fuel system clogging the injector, causing no fuel to enter the cylinder,
and preventing the generator from starting.

Verification/Confirmation
1. Make sure there is proper fuel flow from the low-pressure fuel pump to UCV.
2. Using UCV signal checking tool (included in tool rental kit from Cummins field service engineer
(CFSE)) make sure the proper PWM signal to UCV is present.

Figure 1, Flashing LEDs During Cranking
3. During Cranking the LEDs should be flashing, if the LEDs aren’t flashing you don’t have a PWM
signal from ECM and need to troubleshoot.
4. If there is sufficient fuel supply, correct PWM signal at the UCV terminals, and the unit cranks
but does not start, proceed to the resolution section below.

Resolution
Call 1800-Cummins (1-800-286-6467) to escalate issue to CFSE and coordinate repair. An HDS-II
tool is required to perform the repair and will need to be sent to the repair site to complete a
dataset update on unit and is subject to tool availability. See Service Parts availability to order
replacement UCV (injection pump) PN A072F011
Please see service instructions for repair, manual number A066T114

Service Instructions
Note: After replacing the UCV, the ECM will need to be updated and matched to the new UCV
using the Hatz HDS2 tool.
Make sure new dataset is available on the Hatz server prior to beginning repair by connecting the
unit to a laptop with the HDS2 software installed.

Note: The HDS2 software updates upon computer restart, so restart the computer to see most
recent dataset for the specific serial number. (The update can take a while if it hasn’t been
restarted recently)
Removal
1. Drain the oil.
2. Remove all enclosure panels
3. Pull off the brace on muffler side

Figure 2, Muffler location
4. Remove muffler
5. Remove insulating panel

Figure 3, Removing the insulation panel
6. Remove air box (do not damage or lose gasket stack)

Figure 4, Removal of Air box

Figure 5, Gaskets
7. Remove valve cover - discard old gasket
Note: Put rag below to catch oil seepage.
Note: Order a new valve cover gasket.

Figure 6, Rocker cover
8. Remove return line from top of the injector
9. Remove zip ties from hardline
10. Remove hard line and return line from UCV
11. Remove Banjo supply line and signal wires from the UCV
12. Remove UCV pump
Note: Put rag below to catch oil seepage.

Figure 7, Removal of container clip
13. Remove the retaining clip securing the injector and remove the injector and hardline assembly

Figure 8, Injector removed

Note: Make sure the copper sealing washer is removed before installing the new one with the
UCV kit.
Install
1. Install new UCV pump by evenly thread in mounting bolts.
2. Crimp return line on UCV before installing Injector hardline.

Figure 9, New UCV installed
3. Install new injector and hardline assembly
Note: leave new injector installed on hardline during assembly to keep injector clean.
4. Reinstalled return line and clamp on injector

Figure 10, Installed hardlines
5. Install hardline on UCV
6. Connect UCV signal terminals

Figure 11, UCV signal terminals
7. Zip tie return line to hard line under cylinder head
8. Install zip tie around UCV signal wires
9. Install a new valve cover gasket (A045W750)
10. Reinstall the valve cover
11. Install the air box and all associated gaskets.
Note: Make sure the breather hose is reinstalled
12. Install air filter
13. Install air box cover with fan hose
14. Reinstall insulating panel
15. Reinstall muffler
16. Refill the oil.
Dataset Update
Restart computer to update Hatz tool once dataset for serial number has been updated by Hatz
To complete a dataset update on the HDZAA, a HDS2 tool (Figure 12, #1), pigtail harness (Figure
12, #3) and laptop software is required (Connect at #2). Your local CFSE has access to this Hatz
engine tool and software. These tools can be ordered directly from Hatz (Kit Part Number
65545310).

Figure 12, Pigtail harness
1. Use pigtail wiring harness (#3 from Figure 12) to connect the generator set to the HDS2 tool (#1
from Figure 12).

Figure 13, Pig Tail Connection
2. Verify you have the UCV files on your laptop. They are in C:\MDT\Hatz\XML\IMA_All

Figure 14, UCV Files

3. Connect the USB end of the HDS2 cable to a laptop (#2 from Figure 13) with the HDS software
installed (available on Cummins Software Shelf).
4. Generator display will need to be powered on after cable is connected to laptop but before
software is opened.
5. Once the software has loaded, a screen with the engine identification will show.
6. Locate the "Service" screen
7. Click on “UCV-Kit”

Figure 14, UCV-Kit
8. Make sure HMI is powered on and click “Start”

Figure 16, Start Button
9. Click “Yes” to change the values

Figure 17, Yes Button

10. Enter the UCV Trim Code found on top of UCV.

Figure 18, Enter Trim Code

Figure 19, Trim Code Location
11. Click “Next” once code it entered. If HMI goes to sleep cycle the Red Button to wake it up.
12. The ECM update is now complete.
13. Bench test the unit to make sure functionality

Service Parts Availability
Service parts are available. See Table 1 for part numbers.
Table 1, Service Parts
Part Description

Part Number

UCV (injection pump)

PN A072F011

Gasket, Valve Cover

PN A045W750

Document History
Date
2022-11-10

Details
Module Created

Date

Details

2023-1-11

Non-Product Problem Solving (PPS)

2023-3-24

Non-Product Problem Solving (PPS)

2023-5-4

Non-Product Problem Solving (PPS)

Last Modified: 05-May-2023