IK0800284 ­ Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics

Page 1 of 5

Countries:

CANADA, COLOMBIA, UNITED STATES,
MEXICO, PUERTO RICO

Document
ID:

IK0800284

Availability:

ISIS, FleetISIS

Revision:

8

Major System:
Current
Language:
Other
Languages:

ELECTRICAL SYSTEM

Created:
Last
Modified:

5/16/2011

Viewed:

3650

English
Français, Español,

Author:

4/15/2014
Chris
Moody

Less Info
Coding Information

Hide Details

Copy Link

Copy Relative Link

Bookmark

Add to Favorites

Print

Provide Feedback

View My Bookmarks

Helpful

Not Helpful

100

37

Title : Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics
Applies To : 2010 EPA MaxxForce® 11 and 13 ProStar® and WorkStar®

CONTENT MENU
Click on the items below to jump to each section:
ENGINE DIAGNOSTIC TROUBLE CODES
SENSOR LOCATION
ENGINE CIRCUIT DIAGRAM
CAB AMBIENT TEMPERATURE SENSOR
AAT SENSOR TEMP VS. RESISTANCE CHART
CLUSTER CIRCUIT DIAGRAMS
OTHER RESOURCES
WARRANTY CODING/SRT

ENGINE DIAGNOSTIC TROUBLE CODES
There are two ambient temperature sensors. The sensor located behind the cab along the left frame rail is the sensor the engine uses. To
confirm this, unplug the sensor and observe the cluster LCD display, it the reading stays the same, the correct sensor is unplugged. There is
also a sensor located at the front of the chassis that the gauge cluster uses for the temp display.
This article begins and discusses the Engine AAT Sensor, prior to and first. After August 23, 2013, Some SCR engines have the Engine AAT
sensor mounted in the driver side mirror head and alternatively the sensor could be mounted to the horn bracket. The location depends on build
date.
SPN FMI Module Description
171 4

Engine

AAT signal out of range LOW

171 3

Engine

AAT signal out of range HIGH

171 2

Engine

AAT signal does not agree with other sensors

CIRCUIT DIAGNOSTICS
NOTE: If the ECM is setting/logging code 171 2 and the sensor tests good DO NOT replace the sensor, there is a new calibration available as
of March 7, 2014 for EGR engines, and coming in June 2014 for SCR engines to address this issue.

SENSOR LOCATION
Pre SCR engines and/ SCR Engine prior to August 2013:
The engine sensor is located on the left frame rail midway between the back of cab and front drive axle, or near the front drive axle. The two
photos below show both possible mounting locations (Figure 1 and Figure 2).

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 5/5/2014

IK0800284 ­ Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics

Page 2 of 5

Figure 1

Figure 2

Post August 2013 build w/SCR engine, driver's side mirror head (Figure 3):

Figure 3

ISX and N13 Alternate Location (Figure 4):

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 5/5/2014

IK0800284 ­ Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics

Page 3 of 5

Figure 4

ENGINE CIRCUIT DIAGRAM
Pre SCR engine or SCR Pre August 2013 build date (Figure 5):

Figure 5

Click HERE for the Wiring Schematic for the W/SCR and post August 2013 build date(N13/ISX)

CAB AMBIENT TEMPERATURE SENSOR
The instrument cluster, connector 1501 pin 9, sends a 5-volt source to the temperature sensor. As the voltage goes across the temperature
sensor it decreases, the amount of voltage drop depends on outside temperature. The reduced voltage then returns to the instrument cluster on
pin 8 of connector 1500. The instrument cluster turns the received signal into to the temperature shown on the display.
NOTE: The Electronic Gage Cluster display will replace temperature reading with two dashes (- -) if a fault is present with the Ambient
Temperature Sensor circuit.
SPN FMI Module Description
171 3

Cluster

Fault on Analog Input 3 when used for outside
temperature

171 4

Cluster

Fault on Analog Input 3 when used for outside
temperature

Step

Test Points

Specification

In Spec

NOT In Spec

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 5/5/2014

IK0800284 ­ Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics

1

Page 4 of 5

Measure Resistance of the sensor and compare to
the chart below

Based on
Go To Next Step
Ambient Temp.

Replace Sensor

2

Measure voltage between ambient temperature
sensor connector cavity A and GND

5 +/- 0.5 Vdc

Go To Next Step

Inspect wire from cluster 1501-9 to AAT
sensor pin A for open or short

3

Measure voltage between ambient temperature
sensor connector cavity A and cavity B

5 +/- 0.5 Vdc

Go To Next Step

Inspect ZVR wire from cluster 1500-8 to
AAT sensor pin B for open or short

AAT SENSOR TEMP VS. RESISTANCE CHART

Figure 6

CLUSTER CIRCUIT DIAGRAMS
IMPORTANT: Due to variations during vehicle production, be sure to select the most current wiring schematic manual, specific to the year and
model of the vehicle being serviced.
• ProStar / LoneStar wiring for Cab Sensor
• ProStar / LoneStar wiring for Cab Sensor with Front Axle Load Sensor
• HPV wiring for Cab Sensor
• HPV wiring for Cab Sensor with Front Axle Load Sensor
• TerraStar wiring for Cab Sensor
The Cab Temperature Sensor is typically mounted near the front bumper or on the cooling package. If the sensor cannot be found verify the
wiring to the gauge cluster is present or that the outside air temp monitor feature as ordered on the truck.

OTHER RESOURCES
• IK0800369 - 2006-2009 Cummins Active Fault 249 / 256 Ambient Air Temperature Sensor 1 Circuit

WARRANTY CODING/SRT

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 5/5/2014

IK0800284 ­ Ambient Air Temperature (AAT) Sensor Faults/Location/Diagnostics

Page 5 of 5

NOTE: Claims for this procedure should be coded to: Warranty.
12000

160

Sender, Ambient Temperature

08960

784

Thermometer, Electronic

Return to the Content Menu

Feedback Information

Hide Details

Viewed:

3649

Helpful:

100

Not Helpful: 37

Staff
ID

Client
ID
DYYNJZ1

Comments

Created Date

You received the following feedback From: dyynjz1 ­ Nick Zogelman Email Address: [email protected] Job Classification: SE003, Service Manager 4/15/2014
Dealer: WILLIAMS SERVICE Feedback: WHAT IS NEW ABOUT THIS ARTICLE
11:24:39 AM

Copyright © 2014 Navistar, Inc.

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 5/5/2014