Cutlass L4-138 2.3L VIN A FI HP (1990)
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If the engine is overheating, and the coolant fan is "ON", the cooling system should be checked.
System Diagnosis
Refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS, for wiring schematics.
Neither Coolant Fan Runs
1.
Turn ignition switch to RUN position, disconnect primary coolant fan relay connector and connect a suitable voltmeter between terminal 3
(pink/black VIN T & V) or (red VIN A & D) and ground. Measure voltage.
2.
If no voltage is present, check pink/black or red wire for open.
3.
If battery voltage is present, proceed to Primary Coolant Fan Does Not Run and Secondary Coolant Fan Does Not Run.
Primary Coolant Fan Does Not Run
1.
With ignition switch in RUN position, ground terminal B (white/black) of ALDL connector. If primary coolant fan runs, problem is ECM related.
2.
If primary coolant fan does not run, turn ignition switch to RUN position and ground terminal A9 (dark green/white) at ECM with fused jumper. If
primary coolant fan runs, problem is ECM related.
3.
if primary coolant fan does not run, turn ignition switch to RUN position, leave fused jumper connected as in step 2, disconnect primary coolant
fan relay connector and measure voltage from terminal 4 (red) to ground. If no voltage is present, check for open in red wire.
4.
If battery voltage is present, turn ignition switch to RUN position, leave fused jumper connected as in step 2 and measure voltage between
terminals 4 (red) and 1 (dark green/white). If no voltage is present, check dark green/white wire for open.
5.
If battery voltage is present, disconnect primary coolant fan relay connector and measure voltage from terminal 3 (pink/black VIN T & V) or (red
VIN A & D) to ground. If no voltage is present, check pink/black or red wire for open.
6.
If battery voltage is present, disconnect primary coolant fan relay connector and connect 20 amp fused jumper between terminals 4 (red) and 2
(black/red). If coolant fan runs, check primary coolant fan relay connector terminal contact and, if satisfactory, replace primary coolant fan relay.
7.
If primary coolant fan does not run, leave fused jumper connected as in step 6, disconnect primary coolant fan connector and measure voltage from
terminal B (black/red) to ground. If no voltage is present, check black/red wire for open.
8.
If battery voltage is present, leave fused jumper in place as in step 6 and measure voltage between terminals B (black/red) and A (black).
9.
If no voltage is present, check black wire for open.
10.
If battery voltage is present, check primary coolant fan connector terminals for cleanness and tightness and, if satisfactory, replace primary coolant
fan.
Secondary Coolant Fan Does Not Run
1.
With ignition switch in RUN position, ground terminal A3 (dark blue/white) at ECM with fused jumper. If coolant fan runs, problem is ECM
related.
2.
If coolant fan does not run, leave fused jumper connected as in step 1, disconnect secondary coolant fan relay connector, turn ignition switch to
RUN position and measure voltage from terminal 3 (pink/black) to ground. If no voltage is present, check pink/black wire for open.
3.
If battery voltage is present, leave fused jumper connected as in step 1, turn ignition switch to RUN position and measure voltage between
terminals 3 (pink/black) and 1 (dark blue/white). If no voltage is present, check dark blue/white wire for open.
4.
If battery voltage is present, measure voltage between terminal 4 (red) and ground. If no voltage is present, check red wire for open.
5.
If battery voltage is present, disconnect secondary coolant fan relay connector and connect 20 amp fused jumper between terminals 4 (red) and 2
(black/red).
6.
If coolant fan runs, check secondary coolant fan relay connector terminal contact. If satisfactory, replace secondary coolant fan relay.
7.
If coolant fan does not run, check black/red wire for open and proceed to step 8.
8.
Leave fused jumper connected as in step 5, then disconnect secondary coolant fan connector and measure voltage between terminal B (black/red)
and ground. If no voltage is present, check black/red wire for open.
9.
If battery voltage is present, leave fused jumper connected as in step 5 and measure voltage between terminals B (black/red) and A (black). If no
voltage is present, check black wire for open.
10.
If battery voltage is present, check secondary coolant fan connector and ensure terminals are clean and tight. If satisfactory, replace secondary
coolant fan.
Primary Coolant Fan Runs Continuously With Engine Coolant Cool & A/C Mode Selector Off
1.
Disconnect primary coolant fan relay connector, turn ignition switch to RUN position and connect test lamp between terminals 4 (pink/black) and
1 (dark green/white).
2.
If lamp does not illuminate, replace primary coolant fan relay.
3.
If lamp illuminates, check dark green/white wire for short to ground. If wire is satisfactory, problem is ECM related.
Secondary Coolant Fan Runs Continuously With Engine Coolant Cool & A/C Mode Selector Off
1.
Disconnect secondary coolant fan relay connector, turn ignition switch to RUN position and connect test lamp between terminals 3 (pink/black)
and 1 (dark blue/white).
2.
If lamp does not illuminate, replace secondary coolant fan relay.
