Code Description
Diagnostic Code Listing
Flash
Code
Troubleshooting
Guide Procedure
1.
Check the following on an Electronic Service Tool:Check the following on an Electronic Service Tool:
If both of the above are correctly programmed, inspect
ECM Connector J1/P1 for wire connected to pin-28. If no
wire is present at pin-28 then the ECM is not used to
control the Cooling Fan System. The problem is in the
OEM Vehicle System.
Cooling Fan Type Customer Parameter must be
programmed to "On-Off" or "Three Speed Fan".
If programmed to "None" the fan may always be ON.
For AUG96 and later Personality Modules,
Multi-Function Output #4 Customer Parameter
must be programmed to "Cooling Fan".
If A/C Fan status indicates "DISABLED" then the
ECM does not use and A/C High Pressure Switch to
control the Cooling Fan System.
If parameter indicates "OFF" at any time and the fan
is still ON then the A/C High Pressure circuit is not
the reason the Fan is ON.
If parameter indicates "ACTIVE DIAG", "ON", or
"COUNTING" the fan is ON because of the A/C High
Pressure circuit.
110-00 High Coolant Temp Warning
110-03 Coolant Temp Sensor Open
110-04 Coolant Temp Sensor Shorted
110-11 Very High Coolant Temp
105-00 High Manifold Temp Warning
105-11 Very High Manifold Temp
Engine not running.
During engine cranking.
Coolant sensor temp > 205°F (96°C).
Coolant temp sensor diagnostic active.
Intake manifold air temp > 189°F (87°C).
Intake manifold air temp > 162°F (72°C) with boost
pressure > 10 psi (70 kPa).
Retarder solenoid ON in high mode > 10 seconds.
A/C high pressure switch open or ECM counting.
A/C high pressure switch diagnostic active.
PTO On/Off switch in ON position.
2.
1.
1.
9.
10.
7.
8.
1.
6.
5.
4.
3.
2.
2.
3.
4.
5.
6.
2.
3.
1-11 Cylinder 1 Fault 72 PC-33
3-11 Cylinder 3 Fault 73 PC-33
5-11 Cylinder 5 Fault 74 PC-33
22-13 Check Timing Sensor Calibration 42 PC-32
26-06 Multi-Function Output #1 Short Circuit 69 PB-25
30-13 PTO Throttle Sensor Calibration 29 PB-12
40-06 Mulit-Function Output #2 Short Circuit 66 PB-25
41-04 8 Volt Supply Below Normal 21 PB-12
51-06 Multi-Function Output #3 Short Circuit 67 PB-25
71-01 Idle Shutdown Occurrence 47 PB-21
84-00 Vehicle Overspeed Warning 41 PC-36
84-02 Invalid Vehicle Speed Signal 36 PB-14
84-10 Vehicle Speed Rate of Change 36 PB-14
91-08 Invalid Throttle Signal 32 PB-12
100-01 Low Oil Pressure Warning 46 PC-36
100-04 Oil Pressure Sensor Short Circuit 24 PC-35
102-00 Boost Pressure Reading Stuck High 25 PC-35
102-04 Boost Pressure Sensor Short Circuit 25 PC-35
105-00 High Intake Manifold Temp Warning 64 PC-36
105-04 Intake Manifold Temp Sensor Short Circuit 38 PC-35
108-03 Atmospheric Pr Sensor Open Circuit 26 PC-35
110-00 High Coolant Temperature Warning 61 PC-36
110-04 Coolant Temp Sensor Short Circuit 27 PC-35
111-01 Low Coolant Level Warning 62 PC-36
111-11 Very Low Coolant Level 62 PC-36
121-06 Retarder Solenoid Lo/Hi Short Circuit 14 PB-20
122-06 Retarder Solenoid Med/Hi Short Circuit 14 PB-20
171-03 Outside Air Temp Sensor Open Circuit 00 PC-35
171-11 No Ambient Air Temperature Data 00 PB-21
174-03 Fuel Temp Sensor Open Circuit 13 PC-35
190-00 Engine Overspeed Warning 35 PC-36
228-03 A/C High Pressure Sw Open Circuit 19 PB-18
232-03 5 Volt Supply Above Normal 21 PC-34
244-02 Event Recorder Data Lost 02 PB-11
252-11 Incorrect Engine Software 59 PC-30
253-11 Check Transmission Customer Parameters 56 PC-30
2-11 Cylinder 2 Fault 72 PC-33
4-11 Cylinder 4 Fault 73 PC-33
6-11 Cylinder 6 Fault 74 PC-33
26-05 Multi-Function Output #1 Open Circuit 69 PB-25
30-08 Invalid PTO Throttle Signal 29 PB-12
40-05 Multi-Function Output #2 Open Circuit 66 PB-25
41-03 8 Volt Supply Above Normal 21 PB-12
51-05 Multi-Function Output #3 Open Circuit 67 PB-25
71-00 Idle Shutdown Override 01 PB-21
71-14 PTO Shutdown Occurrence 47 PB-21
84-01 Loss of Vehicle Speed Signal 31 PB-14
84-08 Vehicle Speed Out of Range 36 PB-14
84-14 Quick Stop Occurrence 00 PB-36
91-13 Throttle Sensor Calibration 28 PB-12
100-03 Oil Pressure Sensor Open Circuit 24 PC-35
100-11 Very Low Oil Pressure 46 PC-36
102-03 Boost Pressure Sensor Open Circuit 25 PC-35
102-13 Boost Pressure Sensor Calibration 42 PC-37
105-03 Intake Manifold Temp Sensor Open Circuit 38 PC-35
105-11 Very High Intake Manifold Temp 64 PC-36
108-04 Atmospheric Pr Sensor Short Circuit 26 PC-35
110-03 Coolant Temp Sensor Open Circuit 27 PC-35
110-11 Very High Coolant Temperature 61 PC-36
111-02 Coolant Level Sensor Fault 12 PB-17
121-05 Retarder Solenoid Lo/Hi Open Circuit 14 PB-20
122-05 Retarder Solenoid Med/Hi Open Circuit 14 PB-20
168-02 Low or Intermittent Battery 51 PB-11
171-04 Outside Air Temp Sensor Short Circuit 00 PC-35
174-00 High Fuel Temp Warning 65 PC-36
174-04 Fuel Temp Sensor Short Circuit 13 PC-35
190-02 Loss of Engine RPM Signal 34 PC-31
231-11 J1939 Data Link Fault 58 PB-24
232-04 5 Volt Supply Below Normal 21 PC-34
249-11 J1922 Data Link Fault 58 PB-24
253-02 Check Customer or System Parameters 56 PC-30
254-12 ECM Fault 53 PC-30
ECM is used to control the
Cooling Fan System
Refer to PB-18
Refer to PB-18
NO
"ACTIVE DIAG",
"ON"Or "COUNTING"
YES
"OFF" at any time
or "DISABLED"
No Listed Codes
Cooling Fan Always ON
Turn ignition key ON, engine OFF. Access the Cooling
Fan Driver Special Test on an Electronic Service Tool.
Make the test Active and Not Active while listening for the
solenoid and/or relay to click as test status changes.
Is clicking detected?
Check A/C Fan status parameter on
Electronic Service Tool.
Check for logged or active diagnostic codes as follows:
The following conditions will turn Fan ON if engine
speed < 2250 rpm:
For codes 110-03 and 110-04 refer to procedure
PC-35. For codes 105-00, 105-11, 110-00 and 110-11
refer to procedure PC-36.
Printed in U.S.A.
All Rights Reserved
©1999 Caterpillar
SENR5574-04
January 1999
If no listed condition exists then check for an open
circuit in the solenoid or ECM fan relay circuit. If
problem can not be found refer to procedure PB-18.
Connect Electronic Service Tool to Cab Data Link
and check for ACTIVE Engine Sensor Open or
Short Circuit Code. If the code is not ACTIVE and
the Engine is not running properly, refer to
Troubleshooting Without A Diagnostic Code.
Check Electrical Connectors and Wiring.
Install a short circuit between pin-C and
pin-B of the sensor harness connector
and check for an ACTIVE Short Circuit
Diagnostic Code. Does the Open
Circuit Code remain Active?
Measure the Sensor Supply Voltage with
a Voltmeter. Reading should be within
the range of 4.5 VDC to 5.5 VDC.
If a Short Circuit code was Active before
the sensor was disconnected, but an
Open Circuit code became Active after the
sensor was disconnected then thoroughly
inspect the connector for moisture.
Inspect the seals and connect the sensor.
If the code reappears, the sensor or pigtail
harness is the problem. Temporarily
replace the sensor (connect sensor to
harness but do not install into engine) and
ensure the code is no longer Active. If the
code disappears with a new sensor,
replace the old sensor. STOP.
Disconnect the ECM Connector J2/P2 and check for Active
Diagnostic Codes. The Open Circuit Diagnostic Code
should be Active without the harness connected. Install a
jumper between the Sensor signal pin and pin-30 (Sensor
Common). A Short Circuit Code should be Active with the
jumper in place.
If a Short Circuit Code appears,
temporarily connect the suspect sensor.
If the Open Circuit code returns Active,
replace the sensor and verify the
diagnostic code does not return.
If the Open Circuit Diagnostic Code is not active without
the harness connected, or the Short Circuit Diagnostic
Code does not appear with the short circuit in place,
temporarily install another ECM. Repeat this test step. If
the problem is resolved with the new ECM, verify the
problem returns with the old ECM. If the new ECM works
and the one on the engine did not, replace the ECM. STOP.
Install Sensor Bypass Wiring. Disconnect J2/P2
and remove the sensor signal wire from P2. Install
a 125-3662 3-Pin Engine Sensor Harness Bypass,
or make a bypass and route the bypass wire
directly from the ECM Connector P2 to the Sensor.
ACTIVE
Open or Short
Circuit Code
Refer to PB-10
Short Circuit Code
Active with Jumper
5EK1-UP
9CK1-UP
1YN1-UP
2PN1-UP
6TS1-UP
ACTIVE Open
Circuit Code
OK
Short Circuit
Code Remains
Open Circuit Code
Active with Jumper
OK
OK
Repair or
Replace Harness
Code Changes
To Open Circuit
ACTIVE Short
Circuit Code
Restart Test
NOT
OK
NOT
OK
NOT
OK
NOT
OK
Check Electrical Connectors and Wiring.
Engine Sensor Open or Short Circuit Test
With the ignition key OFF, disconnect the
Sensor Connector with the ACTIVE Short
Circuit Code. Does the Short Circuit
Code remain Active?
NOT
OK
Refer
to
PC-34
P2 J2
TO ECM
MOUNTING
BOLT
INJECTOR COMMON 1 & 2
INJECTOR COMMON 3 & 4
INJECTOR COMMON 5 & 6
INJECTOR 6
INJECTOR 5
INJECTOR 4
INJECTOR 3
INJECTOR 2
INJECTOR 1
RETARDER SOLENOID MED/HI
RETARDER SOLENOID LO/HI
RETARDER SOLENOID COMMON
TDC PROBE+/VEH SP IN+ (NOTE A)
TDC PROBE-/VEH SP IN- (NOTE A)
VEHICLE SPEED OUT - (NOTE A)
VEHICLE SPEED OUT+ (NOTE A)
+V ENG SP/TMG
ENG SP/TMG COMMON
ENG SP/TMG
BOOST PRESSURE
ATM PRESSURE
OIL PRESSURE
COOLANT TEMP
INTAKE MANF AIR TEMP
FUEL TEMP
SENSOR COMMON
+5V
5
17
27
34
28
22
18
12
6
13
19
7
40
39
4
10
16
35
11
32
26
21
31
25
9
24
33
38
1
29
37
23
20
8
15
14
2
3
30
36
ECM GND STRAP
GN
YL
OR
BOOST PRESS.
SENSOR COMMON
+5V
P3 J3
SENSOR
BOOST PRESSURE
A
B
C
A
B
C
SENSOR
SPEED/TIMING
996-GN
998-BR
999-WH
P9 J9
+V ENG SP/TMG
ENG SP/TMG COMMON
ENG SP/TMG
OR
BK
WH
2
1
WH
BK
OR
FUEL TEMP
SENSOR COMMON
+5V
CYL
NO.6
CYL
NO.5
J23 P23
SENSOR
FUEL TEMP
A
B
CYL
NO.4
CYL
NO.3
D789-WH
D790-OR
D791-YL
A706-GY
A705-BU
A704-GN
A703-BR
A702-PU
A701-GY
D786-BR
D787-GN
D788-BK
D784-BU
D810-PU
D811-YL
D785-GN
ENGINE
RETR
SOL CYL
3 & 4
ENGINE
RETR
SOL CYL
1 & 2
WH
BK
OR
A751-YL
993-BR
997-OR
ENGINE
RETR
SOL CYL
5 & 6
C
B
A
SENSOR
INTAKE MANF
AIR TEMP
C967-BU
993-BR
997-OR
J21 P21
INTAKE MANF AIR TEMP
SENSOR COMMON
+5V
WH
BK
OR
OUTSIDE AIR TEMP
GN
YL
OR
D789-WH
D790-OR
D791-YL
A706-GY
A705-BU
A704-GN
A703-BR
A702-PU
A701-GY
D786-BR
D787-GN
D788-BK
OIL PRESSURE
SENSOR COMMON
+5V
P17 J17
SENSOR
OIL PRESSURE
A
B
C
994-GY
993-BR
997-OR
A747-GY
993-BR
997-OR
C
B
A
SENSOR
ATM PRESSURE
P22 J22
ATM PRESSURE
SENSOR COMMON
+5V
GN
YL
OR
12
10
8
6
5
4
3
2
1
11
9
7
A746-PK
993-BR
997-OR
J5 P5
COOLANT TEMP
SENSOR COMMON
+5V
J10 P10
995-BU
993-BR
997-OR
SENSOR
COOLANT TEMP
A
B
C
CYL
NO.1
996-GN
998-BR
999-WH
A746-PK
A747-GY
994-GY
995-BU
C967-BU
A751-YL
993-BR
997-OR
CYL
NO.2
J24 P24
C
1 2 3 4 5 6
35
7
13
19
23
29
12
18
22
28
34
36 37 38 39 40
1
2
3
4
56
789101112
131415
19202122
28 27 26 25 24 23
34 33 32 31 30 29
40 39 38 37 36 35
161718
1 2 3 4 5 6
35
7
13
19
23
29
12
18
22
28
34
36 37 38 39 40
1
2
3
4
56
789101112
131415
19202122
28 27 26 25 24 23
34 33 32 31 30 29
40 39 38 37 36 35
161718
Try to Start the Engine.
Connect Another Service Tool to the
ECM, but use the same Service Tool
Cables as in the previous step.
Connect Electronic Service Tool to Cab Data Link,
turn ignition key ON, engine OFF.
Attempt to access Truck Functions.
Ensure after-market engine protection
devices (not installed by Caterpillar)
are not active, preventing the ECM
from receiving battery power.
Check ECM power and ground
connections with the ignition key switch
ON. Battery voltage at the ECM
Connector P1/J1 pin-6 +Battery to pin-5
-Battery should be 11.0 - 13.5 Volts DC.
If ECM Serial Number ends in "CA",
ensure the Personality Module Chip is
completely snapped into the ECM
socket.
Ensure the Fuel Injector Connector (J5/P5)
is fully connected and free of corrosion.
Observe engine rpm from Electronic
Service Tool while cranking the engine.
If the Personality Module has been
recently replaced/updated, connect and
check for an active 252-11 Incorrect
Engine Software.
If the Truck is equipped with a CAT ID,
ensure Theft Deterrent is not Active.
Turn the ignition key ON, engine OFF,
the CAT ID will indicate Theft Deterrent
Active.
Monitor the exhaust stack while
cranking - if no smoke is present there
may be a fuel supply or fuel quality
problem. Check fuel pressure, fuel
priming, and fuel filters.
Check for combustion problems,
mechanical problems or extreme cold.
Connect the Service Tool Using a
completely different set of Service Tool
Cables.
Disconnect ECM Connector P1 from
the ECM. Install a Caterpillar 129-2018
Harness Bypass. Connect the Bypass
directly to the Electronic Service Tool
Harness and ECM as shown below.
Either the vehicle wiring or another
device on the vehicle is causing
the communication problem.
If ECM Serial Number ends in "CA",
ensure the Personality Module Chip is
completely snapped into the ECM
socket.
ECM does not communicate
OK
OK
OK
ECM and Service Tool
Communicate
OK
OK
OK
OK
OK
OK
OK
NOT
OK
ECM Communicates
Does
not start
No Communications
No Communications
No Communications
Does not crank,
Refer
to
PB-11
Refer
to
PC-30
Refer
to PC-30
Repair
Cables
Repair
Service
Tool
refer to PA-18
Engine Starts, but ECM does not
communicate with the Service Tool.
Refer
to
PC-33
Refer
to
PC-31
Refer
to
PC-30
- +
12V
Caterpillar Harness Bypass
Service Tool P/N 129-2018
Caterpillar
Service Tool "T"
Cable P/N 8T5275
or 139-4166 Cable
ATA DATA LINK +
ATA DATA LINK -
ATA DATA LINK - (J1587)
ATA DATA LINK + (J1587)
+BATTERY
- BATTERY
+BATTERY
- BATTERY
- BATTERY
+ BATTERY
ATA DATA LINK-
ATA DATA LINK+
NOT
OK
NOT
OK
NOT
OK
NOT
OK
NOT
OK
Electronic Service Tool Will Not
Communicate with the ECM
Engine Cranks, But Will Not Start
Harness Bypass Diagram
ECM
Dashed in Area is
Cable Shown Below
- +
12V
G
A
B
H
J
E
D
F
C
1
P1 J1
7
6
5
ECM
Jack Plug
Harness Side Engine Harness
ECM Connector
ECM Side
VOLTAGE SUPPLY WIRES
COMMON WIRES
INPUT SIGNAL WIRES
OUTPUT SIGNALS WIRES
B
B
A
A
C
C
CHECK ENGINE LAMP
WARNING LAMP
SPEEDOMETER-
22
27
10
16
17
11
18
12
20
14
24
25
15
19
13
1
7
6
4
9
3
5
34
35
37
29
8
32
31
30
21
SPEEDOMETER
SENSOR
THROTTLE POSITION
BK
WH
RD
B
J11 P11
+8 V
THROTTLE POSITION
SENSOR COMMON
C
A
+5V
COOL LEVEL NORMAL
COOL LEVEL LOW
SENSOR COMMON
C
D
A
B
COOLANT LEVEL SENSOR
ECM CKT BKR
ECM GND STRAP
TO ECM
MOUNTING
BOLT
+8V
THROTTLE POSITION
SENSOR COMMON
MULTI-FUNCTION INPUT #1
MULTI-FUNCTION INPUT #2
MULTI-FUNCTION INPUT #3
MULTI-FUNCTION SENSOR COMMON
MULTI-FUNCTION OUTPUT #1
CLUTCH SW
SET
RESUME
RETARDER SOLENOID LO/HI SW
RETARDER SOLENOID MED/HI SW
D745-YL
E718-PK
E971-GN
A249-BK
K990-GN
K900-YL
C997-OR
C983-WH
28
40
38
26
39
33
36
2
23
C993-BR
C993-BR
B
A
DASH DATA LINK
F
C
E
D
TO J1939 DATA LINK CONNECTOR
TO J1939 DATA LINK CONNECTOR
TO J1939 DATA LINK CONNECTOR
A/C HIGH PRESS. SW
N/C
E971-GN
+BAT.
-BAT.
ATA+
ATA-
TO J1922 DATA LINK CONNECTOR
TO J1922 DATA LINK CONNECTOR
C993-BR
PASSIVE
MAGNETIC
VEHICLE SPEED
SENSOR
SIGNAL+
SIGNAL-
TACHOMETER
C993-BR
C993-BR
E717-GN
E716-GY
SET/RESUME
COMPONENTS WITHIN THIS AREA ARE CATERPILLAR PROVIDED
CLUTCH N/C
SERVICE BRAKE N/C
(PEDAL RELEASED POSITION)
CRUISE ON/OFF
CHECK ENGINE LAMP
WARNING LAMP
ATA DATA LINK- (J1587)
ATA DATA LINK+ (J1587)
+BATTERY
UNSWITCHED +BATTERY
MULTI-FUNCTION OUTPUT #4 (NOTE B)
MULTI-FUNCTION OUTPUT #2
A/C HIGH PRESSURE SW
J1939 DATA LINK SHIELD (NOTE K)
J1939 DATA LINK- (NOTE K)
J1939 DATA LINK+ (NOTE K)
+5V
COOLANT LEVEL NORMAL
COOLANT LEVEL LOW
J1922 DATA LINK+
J1922 DATA LINK-
-BATTERY
MULTI-FUNCTION OUTPUT #3
VEHICLE SPEED IN-
CRUISE CONT ON/OFF SW
SERVICE BRAKE SW
CIRCUITS WITHIN THIS AREA ARE RECOMMENDATIONS
SPEEDOMETER+
TACHOMETER+
TACHOMETER-
VEHICLE SPEED IN+
VEHICLE SPEED IN-
15
ST
ON
OFF
B
S
C
R
C984-YL
E721-PK
E720-WH
C988-BK
E991-GY
C985-BU
C986-BR
C993-BR
K999-GN
K980-PK
K982-YL
L901-GY
K998-BU
C992-PU
C977-BU
C978-BR
C979-OR
E716-GY
E717-GN
B792-BU
B793-YL
C987-RD
E715-RD
D799-GN
659-PK
C973-GN
C974-PU
450-YL
451-BR
D784-BU
D785-GN
C975-WH
SIGNAL+
SIGNAL-
GS
MTRBAT
STARTER
MOTOR
(12V)
BATTERY 2
N/O
RELAY
KEY SWITCH
GND
ALTERNATOR
-
12V
E715-RD
C987-RD
C988-BK
C997-OR
C983-WH
C984-YL
C993-BR
C985-BU
C986-BR
C993-BR
C978-BR
C979-OR
C977-BU
C992-PU
C975-WH
D784-BU
D785-GN
450-YL
451-BR
C974-PU
C973-GN
659-PK
D799-GN
P1 J1
OEM
INSTALLED
ECM
Jack Plug
Harness Side OEM Vehicle Harness
ECM Connector
ECM Side
+
-
12V
+ +
B793-YL
B792-BU
12V
-
BATTERY 3 BATTERY 1
LO
MED
ENGINE
CYL HEAD
HI
ENGINE RETARDER
SOLENOID SELECTOR SW
ENG GND STUD
(PEDAL RELEASED POSITION)
HI
MED
LO
ENGINE RETARDER
SOLENOID
ON/OFF SW
VOLTAGE SUPPLY WIRES
COMMON WIRES
INPUT SIGNAL WIRES
OUTPUT SIGNALS WIRES
B
B
A
A
C
C
3176B, C-10, C-12, & 3406E OEM Vehicle Harness Wiring Diagram
3176B, C-10, C-12, & 3406E Engine Harness Wiring Diagram
