Mazda 1990 323 Workshop Manual Supplement page 232

K2
TROUBLESHOOTING GUIDE
12
13
14
15
INSPECTION
Check if voltage at IN terminal of EC-AT control
unit is OK
w page K2-144
Voltage: Approx. 12V After engine warmed
up (Above (72% [162OF])
Check if voltage at 22 terminal of engine control
unit is OK
Voltage: Approx. 12V After engine warmed
up (Above 72% [162OF])
Check if voltage at terminal 2Q of engine control
unit is OK
Approx. 2.5V:
Engine coolant temp. 20% (66°F)
Below 0.W: After engine warmed up
Check if operation of water thermosensor is OK
w page *F-142
Yes Go to Step 16
No
Go to next step
Yes
No Go to next step
Yes
Replace engine control unit
No Go to next step
Yes Check for open or short circuit of wiring
and poor connection at connectors
+ If OK, go to next step
c3 If not OK, repair wiring
No
Replace water thermosensor w page *F-142
ACTION
Check for continuity between terminal
1 N of EC-AT control unit and terminal
22 of engine control unit
If OK, try known good EC-AT control
unit and go to next step
If not OK, repair wiring
* Refer to 1990 323 Workshop Manual (1195lo-89E).
K2-56