GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Blazer - 4WD 🢒 Suspension 🢒 Automatic Level Control 🢒 Automatic Level Control Inflator Fill Valve Inoperative

Step

Action

Value(s)

Yes

No

1

Did you review the automatic level control suspension system operation and perform the necessary inspections?

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Go to Step 2

Go to Symptoms

2

Verify that the ALC inflator fill valve is inoperative.

Does the ALC system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3
  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the ALC inflator air switch.
  3. Disconnect the ALC solenoid valve.
  4. Test CKT 1350 (BLK) at terminal B of the ALC inflator air switch for an open circuit.

Is an open present in CKT 1350 (BLK)?

--

Go to Step 4

Go to Step 5

4

Repair the open in CKT 1350 (BLK) between the component and ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 18

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5

Test CKT 1350 (BLK) at terminal B of the ALC solenoid valve for an open circuit.

Is an open present in CKT 1350 (BLK)?

--

Go to Step 4

Go to Step 6

6
  1. Turn the ignition switch to the RUN position. Do not start the engine.
  2. Connect a fused jumper wire from terminal A of the ALC inflator air switch to ground.

Does the ALC Air Compressor pump run?

--

Go to Step 7

Go to Step 8

7

Replace the ALC inflator air switch. Refer to Automatic Level Control Inflator Air Switch Replacement .

Is the replacement complete?

--

Go to Step 18

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8
  1. Turn the ignition switch to the RUN position. Do not start the engine.
  2. Connect a fused jumper wire from terminal E, CKT 321 (YEL) at the ALC timer relay to ground.

Does the ALC Air Compressor pump run?

--

Go to Step 10

Go to Step 9

9

Repair the open in CKT 321 (YEL) between the ALC timer relay and S472. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 18

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10
  1. Ensure that the jumper wire remains connected.
  2. Test CKT 1249 (DK BLU) at terminal A of the ALC solenoid valve for voltage.

Is battery voltage present?

--

Go to Step 14

Go to Step 11

11
  1. Ensure that the jumper wire remains connected.
  2. Test CKT 1249 (DK BLU) terminal C of the ALC timer relay for voltage.

Is battery voltage present?

--

Go to Step 12

Go to Step 13

12

Repair the open in CKT 1249 (DK BLU). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 18

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13

Replace the ALC timer relay. Refer to Automatic Level Control Relay Replacement .

Is the replacement complete?

--

Go to Step 18

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14

Measure the resistance of the ALC solenoid valve.

Is the resistance within the specified range?

20-100 ohms

Go to Step 16

Go to Step 15

15

Replace the ALC solenoid valve. Refer to Automatic Level Control Solenoid Valve Replacement .

Is the replacement complete?

--

Go to Step 18

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16
  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the ALC timer relay.
  3. Test CKT 1267 (PPL) for a short to ground.

Is a short to ground present in CKT 1267 (PPL)?

--

Go to Step 17

Go to Step 13

17

Repair the short to ground in CKT 1267 (PPL). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 18

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18

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3