Engine Cooling System: Overview Pontiac Aztek I

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
2. 3. Determine if the Instrument Cluster or Powertrain Control Modules have set DTC's which may affect Engine Cooling operation are present.
3. 4. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

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The numbers below refer to the step numbers on the diagnostic table.

1. Listen for an audible click when the cooling fan 1 relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. Listen for an audible click when the cooling fan 2 and cooling fan 3 relays operate. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the cooling fan 1 relay. The COOL FAN #1 fuse supplies battery positive voltage to the coil side of the cooling fan 1 relay.

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Symptoms - Engine Cooling

Important: Review the system operation in order to familiarize yourself with the system functions. Refer to COOLING SYSTEM DESCRIPTION AND OPERATION .