Mercury 305 CID - Page 644

ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5E-10390-823225--1 1096
Code 21: TP Sensor Circuit (Scan)
(2 of 2)
• THROTTLE CLOSED.
• IGNITION “ON.”
DOES SCAN TOOL INDICATE THROTTLE
POSITION SENSOR VOLTAGE GREATER
THAN 4 VOLTS OR LESS THAN .36 VOLT?
YES NO
• IGNITION “OFF.”
• CONNECT DVM BETWEEN
THROTTLE POSITION SENSOR
HARNESS TERMINAL “A” AND
GROUND.
• IGNITION “ON.”
IS VOLTAGE OVER 4 VOLTS?
CODE 21 IS INTERMITTENT, REFER TO
“DIAGNOSTIC AIDS” ON FACING PAGE.
NO YES
• IGNITION “OFF.”
• DISCONNECT THROTTLE POSITION
SENSOR CONNECTOR.
• IGNITION “ON.”
DOES SCAN TOOL INDICATE
VOLTAGE OVER 4 VOLTS?
CKT 417 SHORTED
TO VOLTAGE
OR
FAULTY ECM
CONNECTION
OR
FAULTY ECM.
VOLTAGE LESS THAN .36 VOLT.
• IGNITION “OFF.”
• DISCONNECT THROTTLE POSITION SENSOR
ELECTRICAL CONNECTOR. JUMPER THROTTLE
POSITION SENSOR HARNESS TERMINALS “A” AND “C”
TOGETHER.
• IGNITION “ON.”
• SCAN TOOL SHOULD INDICATE THROTTLE
POSITION SENSOR VOLTAGE GREATER THAN 4 VOLTS.
DOES IT?
NO YES
REPLACE THROTTLE
POSITION SENSOR.
CONNECT DVOM
BETWEEN THROTTLE
POSITION HARNESS
CONNECTOR
TERMINALS “C” AND
“A.” VOLTAGE
SHOULD BE GREATER
THAN 4 VOLTS.
IS IT?
VOLTAGE GREATER THAN 4 VOLTS.
NOYES
NO YES
CKT 416 OPEN
OR
FAULTY ECM CONNECTION
OR
FAULTY ECM.
OPEN SENSOR GROUND
CKT 813
OR
FAULTY ECM
CONNECTION
OR
FAULTY ECM.
THROTTLE POSITION
SENSOR SIGNAL (CKT
417) OPEN OR
SHORTED TO
GROUND
OR
FAULTY CONNECTION
AT ECM
OR
FAULTY ECM.
REPLACE THROTTLE
POSITION SENSOR
1
2
3