SERVICE MANUAL NUMBER 23
TROUBLE CODE DIAGNOSTICS - 454/502 MAG MPI & 8.2L MPI
Page 5F-22
90-861326--1 MARCH 1999
Code 14 (2 of 2): Engine Coolant Temperature (ECT) Sensor Circuit (Scan)
Number(s) below refer to step number(s) on the diagnostic table.
Step 2. Code 14 will set if:
•
Signal voltage indicates a coolant temperature above 266
°
F (130
°
C).
•
Signal voltage indicates a coolant temperature below -22
°
F (-30
°
C).
Step 6. This test will determine if CKT 410 is shorted to ground, which will cause the condi-
tion for Code 14.
STEP
ACTION
VALUE
YES
NO
PROCEED TO
1
Was the “On-Board Diagnostic” (OBD) System
Check Performed?
–
Step 2
Go to
OBD
System
Check
2
1. Ignition ON.
Does scan tool display a coolant tempera-
–
Step 3
Step 5
2
p y
p
ture value greater than 266
°
F (130
°
C) or
less than -22
°
F (-30
°
C)?
–
Ste 3
Ste 5
3
Does scan tool display a coolant tempera-
ture value greater than 266
°
F (130
°
C)?
–
Step 6
–
4
Does scan tool display a coolant tempera-
ture value less than -22
°
F (-30
°
C)?
–
Step 7
–
5
Code 14 is intermittent. If no additional codes
were stored, refer to “Diagnostic Aids.”
–
–
–
1. Ignition OFF.
6
2. Disconnect engine coolant temperature
(ECT) sensor.
6
3. Ignition ON.
4. Scan tool should display coolant tempera-
ture below -22
°
F (-30
°
C)
–
Step 9
Step 8
ture below -22
°
F (-30
°
C).
Does it?
–
Ste 9
Ste 8
1. Ignition OFF.
7
2. Disconnect coolant temperature sensor.
7
3. Jumper terminals “A” and “B” together.
4. Ignition ON.
5. Scan tool should display coolant tempera-
ture above 266
°
F (130
°
C)
–
Step 11
Step 10
ture above 266
°
F (130
°
C).
Does it?
–
Ste 11
Ste 10
8
Check for CKT 410 shorted to ground or faulty
ECM.
–
–
–
9
Replace engine coolant temperature sensor.
–
–
–
10
Check CKT 410 open, sensor ground open, or
faulty ECM.
–
–
–
11
Replace engine coolant temperature sensor.
–
–
–
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