Page 149 of 436

TEST TC-38ACONTINUED - REPAIRING - ENGINE SPEED SENSOR STATIC PLAUSIBILITY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY OFF.
TEST TC-38A DISCONNECT ENGINE
CONTINUED FROM SPEED SENSOR AND
PREVIOUS PAGE. THE ECM HARNESS
CONNECTORS.**
MEASURE RESISTANCE REPAIR THE SHORT
USE AN OHMMETER IN BETWEEN GROUND AND IS THE RESISTANCE YES TO GROUND ON THE
THE FOLLOWING THE ENGINE SPEED BELOW 5.0 OHMS? ENGINE SPEED
STEPS. SENSOR SIGNAL CKT. SENSOR CKT.*
FIG. 1
NO
MEASURE RESISTANCE REPAIR THE ENGINE
BETWEEN ENGINE SPEED IS THE RESISTANCE YES SPEED SENSOR
SENSOR SIGNAL CKT BELOW 5.0 OHMS? CIRCUIT FOR A
AND SENSOR GROUND. SHORT TO SENSOR
FIG. 1 GROUND.*
NO
MEASURE THE
RESISTANCE OF THE IS THE RESISTANCE YES REPAIR THE OPEN
ENGINE SPEED ABOVE 5.0 OHMS? ENGINE SPEED
SENSOR CIRCUIT. SENSOR CKT.*
FIG.2
NO
WITH A JUMPER KEY ON. USING A REPAIR THE SHORT
WIRE, CONNECT ECM VOLTMETER, MEASURE IS THE VOLTAGE YES TO VOLTAGE ON THE
HARNESS CONNECTOR THE ENGINE SPEED ABOVE 0.5 VOLTS? ENGINE SPEED
CAVITY 33 TO SENSOR CIRCUIT. SENSOR CKT.*
GROUND. FIG.1
NO
KEY OFF. RECONNECT USING A VOLTMETER TO WITH ENGINE RUNNING,
THE ECM AND ENGINE MEASURE FREQUENCY, IS FREQUENCY BETWEEN YES REPLACE THE ENGINE
SPEED SENSOR BACKPROBE ECM 44 AND 64HZ AT 850 CONTROL MODULE.*
HARNESS HARNESS CONNECTOR RPM AND 150 AND
CONNECTORS. CAVITY 67. FIG.2 190HZ AT 2500 RPM?
NO
REPLACE THE ENGINE
SPEED SENSOR.*
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Page 151 of 436
TEST TC-39AREPAIRING - FAN CONTROL OPEN CIRCUIT FAN 1
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY ON. IS THE RADIATOR
START TEST WITH THE DRB, FAN #2 RELAY NO CONTINUE TEST
TC-39A. ACTUATE THE LOW CLICKING ON AND TC-39A ON THE
SPEED RADIATOR OFF? NEXT PAGE.
FAN.
YES
THE CONDITION TO SET USING THE SCHEMATIC
THE TROUBLE CODE IS AS A GUIDE, INSPECT WERE ANY PROBLEMS YES REPAIR AS
NOT PRESENT. THE WIRING AND FOUND? NECESSARY.*
CONNECTORS.
FIG.1 FIG.2
NO
WIGGLE THE WIRING REPAIR AS NECESSARY
HARNESS FROM THE NOTE: THE DRB MUST DID THE WIGGLING YES WHERE WIGGLING
RELAY TO THE STILL BE ACTUATING INTERRUPT FAN CAUSED FAN RELAY
ENGINE CONTROL THE FAN RELAY. RELAY CLICKING? CLICKING TO BE
MODULE.INTERRUPTED.*
NO
REFER TO GENERAL
INFORMATION 3.3.2
FOR ADDITIONAL TEST COMPLETED.*
INFORMATION ON
INTERMITTENT CODES.
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Page 153 of 436

TEST TC-39ACONTINUED - REPAIRING - FAN CONTROL OPEN CIRCUIT FAN 1
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-39A TURN IGNITION OFF.
CONTINUED FROM
THE PREVIOUS REMOVE RADIATOR
PAGE. FAN RELAY #2.**
TURN IGNITION ON. MEASURE THE DIESEL
POWER RELAY OUTPUT IS THE VOLTAGE NO REPAIR THE OPEN
USE A VOLTMETER IN CIRCUIT. ABOVE 10.0 VOLTS? DIESEL POWER RELAY
THE FOLLOWINGOUTPUT CIRCUIT.*
STEP. FIG.1
YES
TURN IGNITION OFF. MEASURE THE
RESISTANCE BETWEEN IS THE RESISTANCE NO REPLACE RADIATOR
USE AN OHMMETER IN TERMINALS 85 AND 86 BELOW 100.0 OHMS? FAN RELAY #2.*
THE FOLLOWING OF THE #2 RELAY.
STEPS. FIG.2
YES
KEY OFF. MEASURE THE REPAIR THE LOW
DISCONNECT THE ECM RESISTANCE BETWEEN IS THE RESISTANCE YES SPEED FAN CONTROL
HARNESS GROUND AND ECM BELOW 5.0 OHMS? CKT FOR A SHORT TO
CONNECTORS.** HARNESS CONNECTOR GROUND.*
CAVITY 17. FIG.3
NO
MEASURE THE FROM THE RELAY TO
RESISTANCE OF THE ECM HARNESS IS THE RESISTANCE NO REPAIR OPEN LOW
LOW SPEED FAN CONNECTOR CAVITY 17. BELOW 5.0 OHMS? SPEED FAN CONTROL
CONTROL CIRCUIT... CIRCUIT.*
FIG.1 AND 3
YES
REPLACE THE ENGINE
CONTROL MODULE.*
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Page 155 of 436
TEST TC-40AREPAIRING - FAN CONTROL OPEN CIRCUIT FAN 2
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY ON. ARE THE RADIATOR
START TEST WITH THE DRB, FAN RELAYS #1 AND NO CONTINUE TEST
TC-40A. ACTUATE THE HIGH #3 CLICKING ON AND TC-40A ON THE
SPEED RADIATOR OFF? NEXT PAGE.
FAN.
YES
THE CONDITION TO SET USING THE SCHEMATIC
THE TROUBLE CODE IS AS A GUIDE, INSPECT WERE ANY PROBLEMS YES REPAIR AS
NOT PRESENT. THE WIRING AND FOUND? NECESSARY.*
CONNECTORS.
FIG.1 FIG.2
NO
WIGGLE THE WIRING REPAIR AS
HARNESS FROM THE NOTE: THE DRB MUST DID THE WIGGLING YES NECESSARY WHERE
RELAYS TO THE STILL BE ACTUATING INTERRUPT FAN WIGGLING CAUSED
ENGINE CONTROL THE FAN RELAY. RELAY CLICKING? RELAY CLICKING TO
MODULE.BE INTERRUPTED.*
NO
REFER TO GENERAL
INFORMATION 3.3.2
FOR ADDITIONAL TEST COMPLETED.*
INFORMATION ON
INTERMITTENT CODES.
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Page 157 of 436

TEST TC-40ACONTINUED - REPAIRING - FAN CONTROL OPEN CIRCUIT FAN 2
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-40A TURN IGNITION OFF.
CONTINUED FROM
THE PREVIOUS REMOVE RADIATOR FAN
PAGE. RELAYS #1 AND #3.**
TURN IGNITION ON. MEASURE THE DIESEL IS THE VOLTAGE
POWER RELAY OUTPUT ABOVE 10.0 VOLTS NO REPAIR THE OPEN
USE A VOLTMETER IN CIRCUIT AT EACH FOR EACH DIESEL POWER RELAY
THE FOLLOWING RELAY CONNECTOR. MEASUREMENT? OUTPUT CIRCUIT.*
STEP. FIG.1 AND 2
YES
TURN IGNITION OFF. MEASURE THE IS THE RESISTANCE REPLACE THE
RESISTANCE BETWEEN BELOW 100.0 OHMS NO RADIATOR FAN RELAY
USE AN OHMMETER IN TERMINALS 85 AND FOR EACH THAT MEASURED
THE FOLLOWING 86 OF THE #1 AND MEASUREMENT? ABOVE 100.0 OHMS.*
STEPS. #3 RELAYS. FIG.3
YES
KEY OFF. MEASURE THE REPAIR THE HIGH
DISCONNECT THE ECM RESISTANCE BETWEEN IS THE RESISTANCE YES SPEED FAN CONTROL
HARNESS GROUND AND ECM BELOW 5.0 OHMS? CKT FOR A SHORT TO
CONNECTORS.** HARNESS CONNECTOR GROUND.*
CAVITY 41. FIG.4
NO
MEASURE THE FROM EACH RELAY TO
RESISTANCE OF THE ECM HARNESS IS THE RESISTANCE NO REPAIR OPEN HIGH
HIGH SPEED FAN CONNECTOR CAVITY 41. BELOW 5.0 OHMS FOR SPEED FAN CONTROL
CONTROL CIRCUIT... EACH MEASUREMENT? CIRCUIT.*
FIG.1, 2 AND 4
YES
REPLACE THE ENGINE
CONTROL MODULE.*
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Page 159 of 436
TEST TC-41AREPAIRING - FAN CONTROL SHORT CIRCUIT FAN 1
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY ON. IS THE RADIATOR
START TEST WITH THE DRB, FAN #2 RELAY NO CONTINUE TEST
TC-41A. ACTUATE THE LOW CLICKING ON AND TC-41A ON THE
SPEED RADIATOR OFF? NEXT PAGE.
FAN.
YES
THE CONDITION TO SET USING THE SCHEMATIC
THE TROUBLE CODE IS AS A GUIDE, INSPECT WERE ANY PROBLEMS YES REPAIR AS
NOT PRESENT. THE WIRING AND FOUND? NECESSARY.*
CONNECTORS.
FIG.1 FIG.2
NO
WIGGLE THE WIRING REPAIR AS NECESSARY
HARNESS FROM THE NOTE: THE DRB MUST DID THE WIGGLING YES WHERE WIGGLING
RELAY TO THE STILL BE ACTUATING INTERRUPT FAN CAUSED FAN RELAY
ENGINE CONTROL THE FAN RELAY. RELAY CLICKING. CLICKING TO BE
MODULE.INTERRUPTED.*
NO
REFER TO GENERAL
INFORMATION 3.3.2 YES
FOR ADDITIONAL TEST COMPLETED.*
INFORMATION ON
INTERMITTENT CODES.
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Page 161 of 436
TEST TC-41ACONTINUED - REPAIRING - FAN CONTROL SHORT CIRCUIT FAN 1
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-41A
CONTINUED FROM REMOVE RADIATOR
THE PREVIOUS FAN RELAY #2.**
PAGE.
USING AN OHMETER, 85 AND 86 IS THE RESISTANCE
MEASURE RESISTANCE 85 AND 30 BELOW 30.0 OHMS YES REPLACE RADIATOR
BETWEEN RADIATOR 85 AND 87. FOR ANY OF THE FAN RELAY #2.*
FAN #2 RELAY MEASUREMENTS?
TERMINALS... FIG.1
NO
TURN IGNITION OFF.
DISCONNECT THE ECM REMOVE DIESEL
HARNESS POWER RELAY.**
CONNECTORS.**
WITH A JUMPER WIRE,
CONNECT DIESEL POWER
RELAY CONN. CAVITIES TURN IGNITION ON.
30 AND 87 (IN PDC).
FIG.2
MEASURE THE RELAY REPAIR RADIATOR
USE A VOLTMETER IN CONTROL CIRCUIT AT IS THE VOLTAGE YES FAN RELAY #2
THE FOLLOWING ECM HARNESS ABOVE 1.0 VOLT? CONTROL CIRCUIT
STEP. CONNECTOR CAVITY 17. FOR SHORT TO
FIG. 3 VOLTAGE.*
NO
REPLACE THE ENGINE
CONTROL MODULE.*
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Page 163 of 436
TEST TC-42AREPAIRING - FAN CONTROL SHORT CIRCUIT FAN 2
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY ON. ARE THE RADIATOR
START TEST WITH THE DRB, FAN RELAYS #1 AND NO CONTINUE TEST
TC-42A. ACTUATE THE HIGH #3 CLICKING ON AND TC-42A ON THE
SPEED RADIATOR OFF? NEXT PAGE.
FAN.
YES
THE CONDITION TO SET USING THE SCHEMATIC
THE TROUBLE CODE IS AS A GUIDE, INSPECT WERE ANY PROBLEMS YES REPAIR AS
NOT PRESENT. THE WIRING AND FOUND? NECESSARY.*
CONNECTORS.
FIG.1. FIG.2
NO
WIGGLE THE WIRING REPAIR AS
HARNESS FROM THE NOTE: THE DRB MUST DID THE WIGGLING YES NECESSARY WHERE
RELAYS TO THE STILL BE ACTUATING INTERRUPT FAN WIGGLING CAUSED
ENGINE CONTROL THE FAN RELAY. RELAY CLICKING? RELAY CLICKING TO
MODULE.BE INTERRUPTED.*
NO
REFER TO GENERAL
INFORMATION 3.3.2
FOR ADDITIONAL TEST COMPLETED.*
INFORMATION ON
INTERMITTENT CODES.
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