Diagnostic Procedure
FC

SPN FMI

7311 8290

3

Part(s) Affected

Blue iQ® Fault Code 7311

Title
Engine Gaseous Fuel Temperature Regulator Intake Temperature Sensor Circuit –
Voltage Above Normal or Shorted to High Source
pressure/temperature transducer temperature circuit

Diagnostic Overview
Fault Code 7311 is triggered when the Blue iQ® Fuel System Control Module (FSCM) detects the
pressure/temperature transducer temperature circuit is shorted to high source for more than 0.5 seconds.

Warning Statements Used in this Procedure
NOTICE is used to address practices not related to physical injury, such as best
practices or tips to help an operation or procedure go smoothly and prevent equipment
damage.

Tools Required
Item

Purpose

digital multimeter (DMM)

resistance and voltage measurements

J1939 OBD-II diagnostic interface

connect vehicle to Cummins® INSITE™ on PC

Cummins® INSITE™

diagnostic software

test lead kit

test and back probe circuit terminals and connectors without damage

Never probe an electrical connection with anything other than a properly sized
and shaped test lead; doing so may result in damage to terminals.
Perform Initial Vehicle Check procedure (refer to DSM.0009) prior to performing
diagnostic instructions listed below.

Circuit / System Verification
1. Connect Cummins® INSITE™ to the vehicle using a J1939 OBD-II diagnostic interface and navigate to the “Agility®
Fuel Delivery System, CM1881 AFS(18)”.
2. Record all active and stored fault codes and parameters prior to clearing fault codes using INSITE™.
3. Observe and record Engine Gaseous Fuel Temperature Regulator Intake Temperature Sensor data from
INSITE™—is data within reasonable operating range?
a. If not within range, proceed to Circuit/System Testing.
b. If within range, proceed to Step 4.
4. Operate the vehicle in the same conditions for enabling the fault code or within the same conditions that triggered
the fault code based on recorded data.
5. Verify that the fault code does not set. If any fault code sets, proceed to Circuit/System Testing.
6. While observing Engine Gaseous Fuel Temperature Regulator Intake Temperature Sensor parameters in
INSITE™ perform a wiggle test on pressure/temperature transducer and FSCM connectors and harness and
test for poor or intermittent connections.
a. If any fault code sets, proceed to Circuit/System Testing.
b. If no fault code sets, system is functioning to design intent.

7. Review Circuit Schematic and Connector End Views (refer to DSM.0001) to locate test points.
DSM.0034 Ver 1.0
July 19, 2021

Blue iQ® Fault Code 7311 Diagnostic Procedure
PRINTED AND DOWNLOADED COPIES ARE UNCONTROLLED

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Circuit / System Testing
Step
1

 Ignition Off.
 Disconnect pressure/temperature transducer 4-pin connector and FSCM 60-pin connector.
Pressure/temperature
transducer connector end view

FSCM connector end view

1

15

16

30

31

45

46

60

 Examine connectors for the following issues:
1. Loose/not seated into connector
2. Corrosion
3. Bad termination
4. Missing cavity plugs
Damage found?
Yes
 Repair or replace (R/R) connector(s). If R/R is
not possible, replace harness.
 Proceed to Reassembly and Validation.
Step
2

No
 Proceed to Step 2.

 Use DMM and appropriate test leads to perform wire-to-wire continuity test to measure resistance
of each of the following circuits:
1. FSCM connector Pin 29 to pressure/temperature transducer connector Pin 1.
2. FSCM connector Pin 9 to pressure/temperature transducer connector Pin 3.

FSCM harness
connector

Pressure / temperature
transducer harness connector

Resistance between zero and 1 ohm?
Yes
 Repair/replace components(s).
 Proceed to Reassembly and Validation.
DSM.0034 Ver 1.0
July 19, 2021

No
 Proceed to Step 3.

Blue iQ® Fault Code 7311 Diagnostic Procedure
PRINTED AND DOWNLOADED COPIES ARE UNCONTROLLED

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Step
3

 Reconnect FSCM harness connector.
 Ignition On.
 Use DMM and appropriate test leads to measure voltage between Pin 1 (black/white) and Pin 3
(blue) of the pressure/temperature transducer harness connector.
black/white
blue

Pressure/temperature
transducer connector end view

Voltage equal to 0 V?
Yes
 Proceed to Step 4.
Step
4

No
 Repair short to voltage in 5V Signal circuit.
 Proceed to Reassembly and Validation.

 Ignition Off.
 Connect pressure/temperature transducer harness connector.
 Ignition On.
 Use DMM Voltage setting and appropriate test leads to back-probe between pressure/temperature
transducer connector Pin 1 (black/white) and Pin 3 (blue).
black/white
blue

Pressure/temperature
transducer connector end view

Exercise great care to prevent damage to connector seals. Failure to use
correctly sized and shaped test leads to back probe connectors may
result in harness damage.
Voltage equal or greater than 4.5 V?
Yes
 Replace pressure/temperature
transducer.

No
 Record voltage and contact Hexagon Agility®
Technical Support.

Always follow OEM fuel
system depressurization
and repair instructions.

 Proceed to Reassembly and Validation.

DSM.0034 Ver 1.0
July 19, 2021

Blue iQ® Fault Code 7311 Diagnostic Procedure
PRINTED AND DOWNLOADED COPIES ARE UNCONTROLLED

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Reassembly and Validation
After completing all repairs, always perform the following steps to confirm the issue is fixed:
1. Reconnect all connectors and verify connections are secure.
2. Reattach any enclosure covers and close any fuel system doors.
3. Clear fault codes using Cummins® INSITE™ tool.
4. Run vehicle until it reaches normal operating temperature. Refer to OEM instructions.
5. If fault is cleared, return vehicle to duty.

6.

If fault is not cleared, contact Hexagon Agility® Technical Support.

Hexagon Agility® Customer Care and Technical Services
Fuel system warranty or non-warranty product support may be obtained by calling or emailing Hexagon Agility® Customer
Care and Technical Services (CCTS).
Please provide your name, phone number, email address, and complete vehicle information: VIN, year, make, model,
mileage, unit number vehicle owner, and current vehicle location. A service advisor will contact you to arrange vehicle
repair or ship a part.

+1 855 500 2445

(toll-free, U.S. and Canada)

+1 949 267 7745

Support
[email protected]

Parts Orders
[email protected]

Proprietary Statement
The information provided within this document is proprietary and confidential. All prior versions, including updates and revisions forwarded separately, are
proprietary. The information provided by Hexagon Agility® to its customers and clients is solely for the use of those customers and clients. No portion of
this publication may be reproduced or distributed without express written consent of Hexagon Agility®. Hexagon Agility® reserves the right to utilize the
intellectual property contained within this publication as content for any other publication produced by Hexagon Agility®.

Trademark Notice
Hexagon® is a registered trademark of Hexagon Technology AS. Agility® is a registered trademark of Agility Fuel Solutions LLC. Trademarks of other
manufacturers are the property of their respective companies.

Hexagon Agility®

DSM.0034 Ver 1.0
July 19, 2021

3335 Susan Street, Suite 100 Costa Mesa, CA 92626 USA

Blue iQ® Fault Code 7311 Diagnostic Procedure
PRINTED AND DOWNLOADED COPIES ARE UNCONTROLLED

www.hexagonagility.com

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