GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Lumina 🢒 Engine 🢒 Engine Electrical 🢒 Scan Tool Does Not Communicate with Class 2 Device

Diagnostic Aids

The class 2 serial data circuit may have an intermittent open, short to voltage or short to ground. Refer to Testing for Intermittent Conditions and Poor Connections .

Step

Action

Value(s)

Yes

No

1

Does the scan tool power up?

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Go to Step 2

Go to Scan Tool Does Not Power Up

2
  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to communicate with the Powertrain Control Module (PCM).

Does the scan tool communicate with the PCM?

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Go to Diagnostic Aids

Go to Step  3

3
  1. Turn OFF the ignition.
  2. Disconnect the scan tool from the data link connector (DLC).
  3. Inspect for poor connections at the DLC terminals 2 and 5. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Control Module References

Go to Step 4

4

Test the DLC ground circuit terminal 5 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Control Module References

Go to Step 5

5
  1. Disconnect the PCM from the class 2 serial data circuit.
  2. Test the class 2 serial data circuit for a short to ground or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Control Module References

Go to Step 6

6

Test the battery positive voltage circuit(s) and the ignition voltage circuit(s) of the PCM for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Control Module References

Go to Step 7

7
  1. Turn OFF the ignition.
  2. Test the ground circuit of the PCM for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Control Module References

Go to Step 8

8

Test the class 2 serial data circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

9

Inspect for poor connections at the class 2 serial data circuit of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 10

10

Replace the PCM. Refer to Control Module References for the appropriate repair instructions.

Did you complete the replacement?

--

Go to Step 11

--

11
  1. Reconnect the PCM and any disconnected connectors.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Wait for 10 seconds. The scan tool may require a power up reset before communication will occur due to a short on the class 2 serial data circuit. Turn OFF or disconnect the scan tool prior to performing this test.

Does the scan tool communicate with the PCM?

--

Go to Step 12

Go to Step 2

12
  1. Select the Display DTCs function for the PCM.
  2. Record all of the displayed DTCs and the DTC status.

Did you record any DTCs?

--

Go to Step 13

Go to Step 15

13

Diagnose the DTCs as directed by the diagnostic procedures for the PCM or malfunction. Refer to Control Module References for the applicable Diagnostic System Check.

Did you complete the action?

--

Go to Step 14

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14

Did you diagnose all of the DTCs?

--

Go to Step 15

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15

Use the scan tool in order to clear the DTCs if any DTCs are set.

Did you complete the action?

--

System OK

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