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TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
FIG.1
FIG.2
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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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TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
FIG.1
FIG.2
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TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
TEST TC-91A
CONTINUED FROM IS THE VOLTAGE YES CONTINUE TEST
THE PREVIOUS ABOVE 6.0 VOLTS IN TC-91A ON THE
PAGE. THE PREVIOUS STEP? NEXT PAGE.
NO
KEY OFF. KEY ON.
USING A VOLTMETER, IS THE VOLTAGE YES REPLACE THE BODY
DISCONNECT THE BCM MEASURE THE VSS BETWEEN CONTROL MODULE.*
"B" HARNESS SIGNAL CKT. 4.0 AND 6.0 VOLTS?
CONNECTOR.** FIG.1
NO
KEY OFF. USING AN OHMMETER, REPAIR THE VSS
MEASURE BETWEEN IS THE RESISTANCE YES SIGNAL CIRCUIT FOR
DISCONNECT THE ECM VSS SIGNAL CKT AND BELOW 5.0 OHMS? A SHORT TO SENSOR
HARNESS SENSOR GROUND CKT. GROUND CIRCUIT.*
CONNECTORS.** FIG.1
NO
USING AN OHMMETER, REPAIR THE VSS
MEASURE BETWEEN IS THE RESISTANCE YES SIGNAL CIRCUIT FOR
VSS SIGNAL CKT AND BELOW 5.0 OHMS? A SHORT TO
GROUND. GROUND.*
FIG.1
NO
USING AN OHMMETER,
MEASURE THE THE VSS SENSOR AND IS THE RESISTANCE NO REPAIR THE OPEN
RESISTANCE OF THE THE ECM. BELOW 5.0 OHMS? VSS SIGNAL
VSS SIGNAL CKTCIRCUIT.*
BETWEEN... FIG.2
YES
REPLACE THE ENGINE
CONTROL MODULE.*
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TEST TC-91ACONTINUED - REPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
FIG.1
FIG.1
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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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TEST TC-91BREPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
Perform TEST TC-91A Before Proceeding
FIG.1
FIG.2
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TEST TC-91BREPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES
Perform TEST TC-91A Before Proceeding
*Perform Verification TEST VER-2A. **Check connectors - Clean / repair as necessary.
USING THE DRB
START TEST RECONNECT THE VSS RAISE AND SUPPORT OSCILLOSCOPE
TC-91B. AND ECM HARNESS THE VEHICLE DRIVE FUNCTION SELECT
CONNECTORS. AXLE. "LAB SCOPE".
SET VOLTAGE RANGE USING THE
TO +10.0v. SET TIME RANGE TO OSCILLOSCOPE LEAD,
SET PROBE TO x10. 40ms/Div. BACKPROBE ECM
HARNESS CONNECTOR
FIG.1 FIG.2 CAVITY 51. FIG.3
START THE ENGINE. SHIFT TRANSMISSION
INTO FIRST GEAR
ENGAGE THE PARKING AND ALLOW THE
BRAKE. WHEELS TO ROTATE
AT IDLE SPEED.
NOTE: A VALID VSS DOES THE DRB
OBSERVE THE DRB SIGNAL WILL CYCLE DISPLAY THE 5.0 NO REPLACE THE
OSCILLOSCOPE HI TO LOW SIMILAR VOLT VSS SIGNAL VEHICLE SPEED
PATTERN. TO THE PATTERN CYCLING HI AND SENSOR.*
SHOWN IN FIGURE 2. LOW?
YES
REPLACE THE ENGINE
CONTROL MODULE.*
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