Mercury 305 CID - Page 652

ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5E-11190-823225--1 1096
Code 43: KS Circuit (Scan)
(2 of 2)
• INSTALL SCAN TOOL.
• ENGINE IDLING, COOLANT TEMP. ABOVE 150°F (66°C).
DOES SCAN TOOL INDICATE A FIXED VALUE GREATER
THAN ZERO DEGREES OF KNOCK RETARD?
1
3
NO
INSPECT KNOCK SENSOR TERMINAL
CONTACTS. IF OK, REPLACE KNOCK
SENSOR.
2
CHECK FOR OPEN OR SHORT
IN CKT 496.
IF OK, REPLACE KNOCK
SENSOR.
YES
YES NO
CKT 485 OPEN
OR
SHORTED TO GROUND
OR
FAULTY KS MODULE.
REPAIR OPEN
OR
GROUNDED
CKT 439.
NO
• CONNECT A TEST LIGHT TO GROUND.
• DISCONNECT KS MODULE HARNESS CONNECTOR.
• TOUCH THE TEST LIGHT TO KS MODULE HARNESS
CONNECTOR TERMINAL “B” (CKT 439).
IS THE TEST LIGHT “ON”?
5
6
YES
• IGNITION “OFF.”
• DISCONNECT ECM CONNECTOR J-2
• IGNITION “ON.”
• CONNECT DVOM FROM ECM HARNESS
CONNECTOR TERMINAL “C” (CKT 485) TO
GROUND.
ARE 8-10 VOLTS PRESENT?
NO YES
FAULTY ECM.
• RECONNECT 5 WAY KS MODULE CONNECTOR.
• DISCONNECT KNOCK SENSOR HARNESS CONNECTOR.
• CONNECT A TEST LIGHT TO BATTERY POSITIVE (B+).
• START ENGINE.
• HOLD ENGINE SPEED STEADY AT 2500 RPM.
• RAPIDLY TOUCH TEST LIGHT TO KNOCK SENSOR HARNESS
CONNECTOR TERMINAL (CKT 496).
• DOES A NOTICEABLE RPM DROP OCCUR OR USING TIMING LIGHT,
DID TIMING DROP ?
NO
• DISCONNECT KS MODULE HARNESS
CONNECTOR.
• CONNECT A TEST LIGHT TO BATTERY
POSITIVE (B+).
• TOUCH THE TEST LIGHT TO KS HARNESS
CONNECTOR TERMINAL “D” (CKT 486).
IS THE TEST LIGHT “ON”?
YES
• ALLOW DVM VOLTAGE TO STABILIZE.
• RAPIDLY TOUCH A TEST LIGHT CONNECTED TO
BATTERY POSITIVE (B+) TO THE KNOCK
SENSOR HARNESS CONNECTOR TERMINAL (CKT 496).
DOES THE VOLTAGE VALUE CHANGE?
YES NO
CKT 496 OPEN
OR
SHORTED TO GROUND
OR
FAULTY KS MODULE.
REPAIR OPEN
GROUND CKT
486.
4