Page 125 of 436
TEST TC-30AREPAIRING - DIESEL POWER RELAY SHUTS OFF TOO EARLY
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TURN IGNITION ON.
START TEST ARE THERE OTHER YES DIAGNOSE OTHER
TC-30A. USING THE DRB, TROUBLE CODES SET. CODES BEFORE
CHECK FOR CONTINUING.
ADDITIONAL CODES.
NO
USING THE DRB,
ERASE CODES.
PERFORM SEVERAL TURN IGNITION ON.
IGNITION KEY CYCLES DOES THIS CODE YES CONTINUE TEST
PAUSING AT LEAST 10 USING THE DRB, APPEAR? TC-30A ON THE
SECONDS BETWEEN EACH READ CODES. NEXT PAGE.
CYCLE.
NO
AT THIS TIME THE USING THE
CONDITION TO SET SCHEMATIC AS A WERE ANY PROBLEMS YES REPAIR AS
THE TROUBLE CODE GUIDE, INSPECT THE FOUND? NECESSARY.*
IS NOT PRESENT. WIRING AND
FIG.1 CONNECTORS.
NO
REFER TO GENERAL
INFORMATION 3.3.2
FOR ADDITIONAL TEST COMPLETE.*
INFORMATION ON
INTERMITTENT CODES.
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Page 127 of 436

TEST TC-30ACONTINUED - REPAIRING - DIESEL POWER RELAY SHUTS OFF TO EARLY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-30A KEY OFF.
CONTINUED FROM SUBSTITUTE THE
THE PREVIOUS DIESEL POWER RELAY
PAGE. WITH A KNOWN GOOD
RELAY.
PERFORM SEVERAL TURN IGNITION ON.
KEY CYCLES PAUSING DOES THIS CODE NO REPLACE THE
FOR AT LEAST 10 USING THE DRB, APPEAR? INITIAL DIESEL
SECONDS BETWEEN READ CODES. POWER RELAY.*
EACH CYCLE.
YES
KEY OFF.
DISCONNECT THE ECM
REMOVE THE DIESEL HARNESS
POWER RELAY.** CONNECTORS.**
FIG.1
USING AN OHMMETER, WIGGLING THE WAS THE RESISTANCE REPAIR THE
MEASURE RESISTANCE WIRING AND ABOVE 5.0 OHMS AT YES INTERMITTENT OPEN
OF THE DIESEL POWER CONNECTORS BETWEEN ANY TIME WHILE IN THE DIESEL
RELAY CONTROL CKT THE ECM AND PDC. WIGGLING? POWER RELAY
WHILE... FIG.1 CONTROL CIRCUIT.*
NO
REINSTALL THE DIESEL
POWER RELAY.
RECONNECT THE ECM
HARNESS CONNECTORS.
PERFORM SEVERAL TURN IGNITION ON.
KEY CYCLES PAUSING DOES THIS CODE YES REPLACE THE ENGINE
FOR AT LEAST 10 USING THE DRB, APPEAR? CONTROL MODULE.*
SECONDS BETWEEN READ CODES.
EACH CYCLE.
NO
TEST COMPLETE.*
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Page 129 of 436
TEST TC-31AREPAIRING - DIESEL POWER RELAY SHUTS OFF TOO LATE
Perform TEST DTC Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TURN IGNITION ON.
START TEST ARE THERE OTHER YES DIAGNOSE OTHER
TC-31A. USING THE DRB, TROUBLE CODES SET. CODES BEFORE
CHECK FOR CONTINUING.
ADDITIONAL CODES.
NO
USING THE DRB,
ERASE CODES.
PERFORM SEVERAL TURN IGNITION ON.
IGNITION KEY CYCLES DOES THIS CODE YES CONTINUE TEST
PAUSING AT LEAST 10 USING THE DRB, APPEAR? TC-31A ON THE
SECONDS BETWEEN EACH READ CODES. NEXT PAGE.
CYCLE.
NO
AT THIS TIME THE USING THE
CONDITION TO SET SCHEMATIC AS A WERE ANY PROBLEMS YES REPAIR AS
THE TROUBLE CODE GUIDE, INSPECT THE FOUND? NECESSARY.*
IS NOT PRESENT. WIRING AND
FIG.1 CONNECTORS.
NO
REFER TO GENERAL
INFORMATION 3.3.2
FOR ADDITIONAL TEST COMPLETE.*
INFORMATION ON
INTERMITTENT CODES.
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Page 131 of 436

TEST TC-31ACONTINUED - REPAIRING - DIESEL POWER RELAY SHUTS OFF TOO LATE
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-31A KEY OFF.
CONTINUED FROM SUBSTITUTE THE
THE PREVIOUS DIESEL POWER RELAY
PAGE. WITH A KNOWN GOOD
RELAY. FIG.1
PERFORM SEVERAL TURN IGNITION ON.
KEY CYCLES PAUSING DOES THIS CODE NO REPLACE THE
FOR AT LEAST 10 USING THE DRB, APPEAR? INITIAL DIESEL
SECONDS BETWEEN READ CODES. POWER RELAY.*
EACH CYCLE.
YES
KEY OFF.
DISCONNECT THE ECM
REMOVE THE DIESEL HARNESS
POWER RELAY.** CONNECTORS.**
FIG.1
USING AN OHMMETER, WIGGLING THE WAS THE RESISTANCE REPAIR THE
MEASURE RESISTANCE WIRING AND BELOW 5.0 OHMS AT YES INTERMITTENT SHORT
BETWEEN GROUND AND CONNECTORS BETWEEN ANY TIME WHILE TO GROUND IN THE
DIESEL POWER RELAY THE ECM AND PDC. WIGGLING? DIESEL POWER RELAY
CONTROL CKT WHILE... FIG.1 CONTROL CIRCUIT.*
NO
REINSTALL THE DIESEL
POWER RELAY.
RECONNECT THE ECM
HARNESS CONNECTORS.
PERFORM SEVERAL TURN IGNITION ON.
KEY CYCLES PAUSING DOES THIS CODE YES REPLACE THE ENGINE
FOR AT LEAST 10 USING THE DRB, APPEAR? CONTROL MODULE.*
SECONDS BETWEEN READ CODES.
EACH CYCLE.
NO
TEST COMPLETE.*
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Page 135 of 436

TEST TC-33ACONTINUED - REPAIRING - EGR OPEN CIRCUIT
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-33A TURN IGNITION OFF.
CONTINUED FROM DISCONNECT THE EGR
THE PREVIOUS SOLENOID HARNESS
PAGE. CONNECTOR.**
KEY ON. USING A
VOLTMETER, MEASURE IS THE VOLTAGE YES REPAIR THE OPEN
THE DIESEL POWER BELOW 10.0 VOLTS? DIESEL POWER RELAY
RELAY OUTPUT CKT. OUTPUT CKT.*
FIG.1
NO
TURN IGNITION OFF. USING AN OHMMETER, REPAIR THE SHORT
DISCONNECT THE ECM MEASURE THE EGR IS THE RESISTANCE YES TO GROUND OF THE
HARNESS SOLENOID CONTROL BELOW 5.0 OHMS? EGR SOLENOID
CONNECTORS.** CIRCUIT TO GROUND. CONTROL CKT.*
FIG.1
NO
USING AN OHMMETER,
MEASURE THE EGR IS THE RESISTANCE YES REPAIR THE OPEN
SOLENOID CONTROL ABOVE 5.0 OHMS? EGR SOLENOID
CIRCUIT. CONTROL CKT.*
FIG.2
NO
RECONNECT THE ECM
REPLACE THE EGR AND EGR SOLENOID DOES THE EGR CODE YES REPLACE THE ENGINE
SOLENOID. CONNECTORS. KEY RESET? CONTROL MODULE.*
ON. USING THE DRB,
CHECK FOR CODES.
NO
TEST COMPLETE.*
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Page 139 of 436
TEST TC-34ACONTINUED - REPAIRING - EGR SHORT CIRCUIT
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY ON.
USING THE DRB,
ERASE CODES.USING THE DRB
DISPLAY ECM CODES.DOES THE DRB DISPLAY
``EGR SHORT
CIRCUIT''?
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Page 143 of 436

TEST TC-35ACONTINUED - REPAIRING - ENGINE SPEED SENSOR DYNAMIC PLAUSIBILITY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY OFF.
TEST TC-35A 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 ENGINE SPEED BELOW 5.0 OHMS? ENGINE SPEED
STEPS. SENSOR SIGNAL CKT. SENSOR CKT.*
FIG.1
NO
MEASURE RESISTANCE REPAIR THE ENGINE
BETWEEN THE ENGINE IS THE RESISTANCE YES SPEED SENSOR
SPEED SENSOR SIGNAL BELOW 5.0 OHMS? CIRCUIT FOR A
CKT AND SENSOR SHORT TO SENSOR
GROUND. 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. REMOVE USING A VOLTMETER TO WITH ENGINE RUNNING,
JUMPER WIRE. MEASURE FREQUENCY, IS FREQUENCY BETWEEN YES REPLACE THE ENGINE
RECONNECT ECM AND BACKPROBE ECM 44 AND 64HZ AT 850 CONTROL MODULE.*
ENGINE SPEED SENSOR HARNESS CONNECTOR RPM AND 150 AND
HARNESS CONNECTORS. CAVITY 67. FIG.2 190HZ AT 2500 RPM?
NO
REPLACE THE ENGINE
SPEED SENSOR.*
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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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