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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Catera 🢒 DTC 🢒 DTC 37 Heater and A/C Control Switch Stuck

DTC 37 Heater and A/C Control Switch Stuck for Cadillac Catera 2000

Circuit Description

When the A/C switch is pressed on the heater and A/C control, an internal timer begins counting the amount of time the A/C switch is being depressed. The timer stops counting when the switch is released.

Conditions for Running the DTC

The diagnostic runs every 40 ms.

Conditions for Setting the DTC

The A/C switch is active for at least 15 counts.

Action Taken When the DTC Sets

The DTC is stored in memory.

Conditions for Clearing the DTC

The DTC clears after 20 fault-free ignition cycles.

Step

Action

Value(s)

Yes

No

1

Did you perform the HVAC Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the A/C SWITCH parameter in the Heating and Air Conditioning data list.

Does the scan tool display INACTIVE?

--

Go to Step 3

Go to Step 4

3
  1. Activate the A/C button on the heater and A/C control.
  2. With a scan tool, observe the A/C SWITCH parameter.

Does the A/C SWITCH parameter change state?

--

Go to Testing for Electrical Intermittents

Go to Step 5

4

Does the scan tool display ACTIVE at all times?

--

Go to Step 5

--

5
  1. Replace the heater and A/C control.
  2. Use the scan tool in order to program the new controller.

Did you complete the replacement?

--

Go to Step 6

--

6
  1. Use the scan tool in order to clear the DTCs.
  2. Press the A/C switch ON and OFF several times.

Does the DTC reset?

--

Go to Step 2

System OK