Page 209 of 436

TEST TC-56ACONTINUED - REPAIRING - INDUCTIVE AUXILIARY SPEED SENSOR DYNAMIC
PLAUSIBILITY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TURN IGNITION OFF.
TEST TC-56A DISCONNECT THE
CONTINUED FROM NEEDLE MOVEMENT
PREVIOUS PAGE. SENSOR HARNESS
CONNECTOR.**
INSPECT THE NEEDLE THE SENSOR HARNESS IS THERE ANY
MOVEMENT SENSOR AND ENGINE HARNESS. DAMAGE OR YES REPAIR AS
CONNECTOR CORROSION AT NECESSARY.*
TERMINALS AT EITHER HARNESS
BOTH.... FIG.1 AND 2. CONNECTOR?
NO
CHECK THE WIRING THIS INTERFERENCE
HARNESS FOR COULD BE CAUSED BY IS THE WIRING YES REPAIR AS
MIS-ROUTING THAT LARGE CURRENT HARNESS NECESSARY.*
COULD INDUCE CARRYING WIRES OR MIS-ROUTED?
INTERFERENCE. THE ALTERNATOR.
NO
DISCONNECT THE ECM THE NEEDLE REPAIR THE OPEN IN
HARNESS MOVEMENT SENSOR IS THE RESISTANCE YES THE NEEDLE
CONNECTORS.** USING SIGNAL CIRCUIT. ABOVE 5.0 OHMS? MOVEMENT SENSOR
AN OHMMETER, MEASURESIGNAL CIRCUIT.*
THE RESISTANCE OF... FIG.3
NO
KEY OFF. REPLACE THE START AND OPERATE
NEEDLE MOVEMENT THE ENGINE FROM DOES THIS CODE YES REPLACE THE ENGINE
SENSOR. RECONNECT IDLE TO 3500 RPM RESET? CONTROL MODULE.*
ALL CONNECTORS. KEY WHILE MONITORING
ON. ERASE CODES. THE DRB.
NO
TEST COMPLETE.*
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Page 213 of 436

TEST TC-57ACONTINUED - REPAIRING - INDUCTIVE AUXILIARY SPEED SENSOR OVERSPEED
RECOGNITION
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TURN IGNITION OFF.
TEST TC-57A DISCONNECT THE
CONTINUED FROM NEEDLE MOVEMENT
PREVIOUS PAGE. SENSOR HARNESS
CONNECTOR.**
INSPECT THE NEEDLE THE SENSOR HARNESS IS THERE ANY
MOVEMENT SENSOR AND ENGINE DAMAGE OR YES REPAIR AS
CONNECTOR HARNESS. CORROSION AT NECESSARY.*
TERMINALS AT EITHER HARNESS
BOTH.... FIG. 1 AND 2 CONNECTOR?
NO
CHECK THE WIRING THIS INTERFERENCE
HARNESS FOR COULD BE CAUSED BY IS THE WIRING YES REPAIR AS
MIS-ROUTING THAT LARGE CURRENT HARNESS NECESSARY.*
COULD INDUCE CARRYING WIRES OR MIS-ROUTED?
INTERFERENCE. THE ALTERNATOR.
NO
DISCONNECT THE ECM THE NEEDLE REPAIR THE OPEN IN
HARNESS MOVEMENT SENSOR IS THE RESISTANCE YES THE NEEDLE
CONNECTORS.** USING SIGNAL CIRCUIT. ABOVE 5.0 OHMS? MOVEMENT SENSOR
AN OHMMETER MEASURESIGNAL CIRCUIT.*
THE RESISTANCE OF... FIG.3
NO
REPLACE THE NEEDLE START AND OPERATE
MOVEMENT SENSOR. THE ENGINE FROM DOES THIS CODE YES REPLACE THE ENGINE
RECONNECT ALL IDLE TO 3500 RPM RESET? CONTROL MODULE.*
CONNECTORS. KEY WHILE MONITORING
ON. ERASE CODES. THE DRB.
NO
TEST COMPLETE.*
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Page 217 of 436

TEST TC-58ACONTINUED - REPAIRING - INDUCTIVE AUXILIARY SPEED SENSOR PLAUSIBILITY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TURN IGNITION OFF.
TEST TC-58A DISCONNECT THE
CONTINUED FROM NEEDLE MOVEMENT
PREVIOUS PAGE. SENSOR HARNESS
CONNECTOR.**
INSPECT THE NEEDLE THE SENSOR HARNESS IS THERE ANY
MOVEMENT SENSOR AND ENGINE DAMAGE OR YES REPAIR AS
CONNECTOR HARNESS. CORROSION AT NECESSARY.*
TERMINALS AT EITHER HARNESS
BOTH.... FIG. 1 AND 2 CONNECTOR?
NO
CHECK THE WIRING THIS INTERFERENCE
HARNESS FOR COULD BE CAUSED BY IS THE WIRING YES REPAIR AS
MIS-ROUTING THAT LARGE CURRENT HARNESS NECESSARY.*
COULD INDUCE CARRYING WIRES OR MIS-ROUTED?
INTERFERENCE. THE ALTERNATOR.
NO
DISCONNECT THE ECM THE NEEDLE REPAIR THE OPEN IN
HARNESS MOVEMENT SENSOR IS THE RESISTANCE YES THE NEEDLE
CONNECTORS.** USING SIGNAL CIRCUIT. ABOVE 5.0 OHMS? MOVEMENT SENSOR
AN OHMMETER, MEASURESIGNAL CIRCUIT.*
THE RESISTANCE OF... FIG.3
NO
REPLACE THE NEEDLE START AND OPERATE
MOVEMENT SENSOR. THE ENGINE FROM DOES THIS CODE YES REPLACE THE ENGINE
RECONNECT ALL IDLE TO 3500 RPM RESET? CONTROL MODULE.*
CONNECTORS. KEY ON WHILE MONITORING
ERASE CODES. THE DRB.
NO
TEST COMPLETE.*
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Page 221 of 436

TEST TC-59ACONTINUED - REPAIRING - INDUCTIVE AUXILIARY SPEED SENSOR STATIC
PLAUSIBILITY
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-59A TURN IGNITION OFF.
CONTINUED FROM DISCONNECT THE
THE PREVIOUS NEEDLE MOVEMENT
PAGE. SENSOR HARNESS
CONNECTOR.*
INSPECT THE NEDLE THE SENSOR HARNESS
MOVEMENT SENSOR AND THE ENGINE IS THERE DAMAGE OR YES REPAIR AS
CONNECTOR AT HARNESS. CORROSION AT NECESSARY.*
BOTH... EITHER HARNESS?
FIG.1 AND 2.
NO
CHECK THE WIRING THIS INTERFERENCE
HARNESS FOR COULD BE CAUSED BY IS THE WIRING YES REAPIR AS
MIS-ROUTING THAT LARGE CURRENT HARNESS NECESSARY.*
COULD CAUSE CARRYING WIRES OR MIS-ROUTED?
INTERFERNCE. THE ALTERNATOR.
NO
USING AN OHMMETER, REPAIR THE OPEN IN
DISCONNECT THE ECM MEASURE THE NEEDLE IS THE RESISTANCE YES THE NEEDLE
HARNESS MOVEMENT SENSOR ABOVE 5.0 OHMS? MOVEMENT SENSOR
CONNECTORS.** SIGNAL CIRCUIT. SIGNAL CIRCUIT.*
FIG.3
NO
REPLACE THE NEEDLE START AND OPERATE
MOVEMENT SENSOR. THE ENGINE FROM DOES THE CODE YES REPLACE THE ENGINE
RECONNECT ALL IDLE TO 3500 RPM RESET? CONTROL MODULE.*
CONNECTORS. KEY WHILE MONITORING
ON. ERASE CODES. THE DRB.
NO
TEST COMPLETE.*
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Page 225 of 436

TEST TC-62ACONTINUED - REPAIRING - INTAKE AIR TEMPERATURE SENSOR SIGNAL HIGH
EXCEEDED
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-62A KEY OFF.
CONTINUED FROM DISCONNECT THE
THE PREVIOUS BOOST PRESSURE
PAGE. SENSOR HARNESS
CONNECTOR.**
WITH A JUMPER WIRE, TURN IGNITION ON.
DISCONNECT THE ECM REMOVE THE DIESEL CONNECT DIESEL POWER
HARNESS POWER RELAY.** RELAY CONN. CAVITIES USE A VOLTMETER IN
CONNECTORS.** 30 AND 87 (IN PDC). THE FOLLOWING
FIG.1 STEP.
MEASURE THE IAT REPAIR THE INTAKE
SENSOR SIGNAL IS THE VOLTAGE YES AIR TEMPERATURE
CIRCUIT. ABOVE 1.0 VOLT? SENSOR SIGNAL
CIRCUIT FOR A
FIG.2 SHORT TO VOLTAGE.*
NO
KEY OFF. USING AN OHMMETER, REPAIR THE OPEN
MEASURE THE IAT IS THE RESISTANCE NO INTAKE AIR
REMOVE THE JUMPER SENSOR SIGNAL BELOW 5.0 OHMS? TEMPERATURE SENSOR
WIRE. CIRCUIT. SIGNAL CIRCUIT.*
FIG.3
YES
CONNECT A JUMPER DOES THE DRB
BETWEEN THE INTAKE WITH THE DRB, DISPLAY "INTAKE YES REPLACE THE BOOST
AIR TEMP SENSOR ERASE AND THEN AIR TEMPERATURE PRESSURE SENSOR.*
SIGNAL AND SENSOR READ CODES. SENSOR LOW
GROUND CKT. FIG.1 EXCEEDED"?
NO
MOVE THE JUMPER DOES THE DRB
WIRE FROM THE WITH THE DRB, READ DISPLAY "INTAKE YES REPAIR THE OPEN
SENSOR GROUND TO CODES. AIR TEMPERATURE SENSOR GROUND
AN ENGINE GROUND. SENSOR LOW CIRCUIT.*
EXCEEDED"?
NO
REPLACE THE ENGINE
CONTROL MODULE.*
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Page 279 of 436
TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
KEY OFF.
TEST TC-91A
CONTINUED FROM DISCONNECT THE VSS
PREVIOUS PAGE. HARNESS
CONNECTOR.**
USING A VOLTMETER, REPAIR THE
MEASURE THE FUSED IS THE VOLTAGE NO IGNITION SWITCH
TURN IGNITION ON. IGNITION SWITCH ABOVE 10.0 VOLTS? OUTPUT CIRCUIT FOR
OUTPUT CKT. AN OPEN OR SHORT
FIG.1 TO GROUND.*
YES
USING A VOLTMETER,
MEASURE THE VSS IS THE VOLTAGE NO CONTINUE TEST
SIGNAL CIRCUIT. BETWEEN TC-91A ON THE
4.0 AND 6.0 VOLTS? NEXT PAGE.
FIG.1
YES
KEY OFF. USING AN OHMMETER,
MEASURE RESISTANCE IS THE RESISTANCE NO REPAIR THE OPEN
DISCONNECT THE ECM OF SENSOR GROUND CKT BELOW 5.0 OHMS? SENSOR GROUND
HARNESS BETWEEN ECM AND VSS. CIRCUIT.*
CONNECTORS.** FIG.2
YES
PERFORM TEST
TC-91B.
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Page 283 of 436
TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-91A KEY OFF.
CONTINUED FROM
THE PREVIOUS DISCONNECT THE BCM
PAGE. "B" HARNESS
CONNECTOR.**
USING A VOLTMETER,
MEASURE THE VSS IS THE VOLTAGE YES REPLACE THE BODY
TURN IGNITION ON. SIGNAL CKT. BELOW 5.0 VOLTS? CONTROL MODULE.*
FIG.1
NO
KEY OFF.
REMOVE THE DIESEL
DISCONNECT THE ECM POWER RELAY.*
HARNESS
CONNECTORS.* FIG.2
WITH A JUMPER WIRE, KEY ON. USING A REPAIR THE VSS
CONNECT DIESEL POWER VOLTMETER, MEASURE IS THE VOLTAGE NO SIGNAL CIRCUIT FOR
RELAY CONNECTOR THE VSS SIGNAL CKT. ABOVE 1.0 VOLT? A SHORT TO
CAVITIES 30 AND 87 VOLTAGE.*
(IN PDC). FIG.2 FIG.1
YES
REPLACE THE ENGINE
CONTROL MODULE.*
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Page 289 of 436

TEST TC-94ACONTINUED - REPAIRING - VEHICLE THEFT ALARM TROUBLE CODES
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-94A
CONTINUED FROM
THE PREVIOUS TURN IGNITION OFF.
PAGE.
DISCONNECT THE
DISCONNECT THE ECM BODY CONTROL
HARNESS MODULE HARNESS
CONNECTORS.** CONNECTORS.**
USING AN OHMMETER, BETWEEN THE BCM
MEASURE RESISTANCE AND THE ECM. IS THE RESISTANCE YES REPAIR THE OPEN
OF THE IMMOBILIZER ABOVE 5.0 OHMS? IMMOBILIZER SIGNAL
SIGNAL CIRCUIT... CIRCUIT.*
FIG.1
NO
ENGINE CONTROL REPAIR THE
MEASURE RESISTANCE MODULE HARNESS IS THE RESISTANCE YES IMMOBILIZER SIGNAL
BETWEEN THE ... CONNECTOR CAVITY BELOW 5.0 OHMS? CIRCUIT FOR A
38 AND GROUND. SHORT TO GROUND.*
NO
WITH A JUMPER WIRE,
REMOVE THE DIESEL CONNECT DIESEL POWER
POWER RELAY.** RELAY CONN. CAVITIES
30 AND 87 (IN PDC).
FIG.2
USING A VOLTMETER, REPAIR THE
MEASURE ECM IS THE VOLTAGE YES IMMOBILIZER SIGNAL
TURN IGNITION ON. HARNESS CONNECTOR ABOVE 1.0 VOLT? CIRCUIT FOR A
CAVITY 38. SHORT TO VOLTAGE.*
FIG.1
NO
CONTINUE TEST
TC-94A ON THE
NEXT PAGE.
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