Ford Corsar Repair Manual page 219

TROUBLE DIAGNOSES
DIAGNOSTIC PROCEDURE 13
-
CODE 15
-
WATER TEMPERATURE SENSOR (VOLTAGE HIGH).
CODE 15 IS SET IF:
(1)
The WTS indicates the temp.
<
-20 degrees Celcius.
AND
(2)
This condition exists for more than 25.5 seconds with the engine running.
Ignition "off': clear codes.
Diagnostic bridge removed.
Start warm engine and run for 2
minutes, or until ECM light comes on.
lgnition "on'', engine stopped bridge diagnostic
test terminal and note code.
1
Disconnect coolant sensor connector.
1
I
I
i
I
Ignition "on': engine stopped.
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Code 15
Check voltage between harness
1
connector terminals circuits AN17 and AN20.
I
No Code 15
Problem is intermittent. If no other
codes were stored. Look for poor
electrical connection in WTS circuit.
m m
I
Check resistance across coolant sensor
terminals. See table for a ~ ~ r o x i m a t e
I
Repair short to voltage
1
on circuit AN17.
Should be 4-6 volts.
I
Probe coolant sensor harness
connector circuit AN17 with a
temperature to sensor residance values.
I
1
voltmeter to earth.
I
Check for intermittent or
loose terminals in sensor
harness connector.
Terminals may not be connecting
to sensor when connected.
1
If ok, replace ECM.
I
Not Ok
Sensor.
I I
ENGINE COOLANT SENSOR
27
ECM
- 1
I
DIAGNOSTICS INPUT
- A
Check for open
Circuit AN20.
If ok, check ECM
connector
terminals.
If ok, r e ~ l a c e ECM.
Check for open
circuit AN17
If ok, check ECM
connector
terminals.
If ok, replace ECM.
Clear codes, run engine for 2 minutes and re-check for codes.
Coolant sensor
temp. to resistance values
(approximate).
O C
110
100
90
70
40
30
20
0
-10
-20
OHMS
146
188
247
444
1,191
1,716
2,523
5,860
9,307
15,258