GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Catera 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Scan Tool Does Not Communicate with Instrument Cluster

Step

Action

Value(s)

Yes

No

1

Was the Data Link Communications System Check performed?

--

Go to Step 2

Go to Data Link Communications System Check

2

Attempt to establish communication with the other modules connected to the circuit.

    • Engine Control Module (ECM)
    • Memory Seat Module (MSM)
    • Transmission Control Module (TCM)

Does the scan tool communicate with the other modules?

--

Go to Step 3

Go to Step 4

3
  1. Disconnect the instrument cluster connector.
  2. Measure the resistance between the instrument cluster connector terminal 24 and the data link connector (DLC) terminal 7.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 5

Go to Step 6

4
  1. Disconnect the ECM connector.
  2. Attempt to communicate with the other modules.

Does the scan tool communicate with the other modules?

--

Go to Step 7

Go to Step 8

5

Inspect for poor connections at terminal 24. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Did you find and correct the poor connection condition?

--

Go to Step 9

Go to Step 10

6

Locate and repair an open in CKT XM500 (BRN/WHT).

Is the repair complete?

--

Go to Step 9

--

7

Replace the ECM.

Is the replacement complete?

--

Go to Step 9

--

8
  1. Reconnect the ECM.
  2. Disconnect connector C1 from the MSM.
  3. Attempt to communicate with the other modules.

Does the scan tool communicate with the other modules?

--

Go to Step 12

Go to Step 13

9

Attempt to establish communications with the instrument cluster.

Does the scan tool communicate with the instrument cluster?

--

System OK

Go to Step 2

10
  1. Inspect the HZD fuse for an open.
  2. Inspect and test the instrument cluster battery feed circuit at terminal 25 for proper voltage (11-13 V).
  3. Inspect the HZD fuse for an open.
  4. Inspect and test the instrument cluster ignition feed circuit at terminal 19 for proper voltage with the KEY ON (11-13 V).
  5. Inspect and test the ground circuit at terminal 26.
  6. Make necessary repairs.

Did you find and correct any conditions?

--

Go to Step 9

Go to Step 15

11

Replace the TCM.

Is the replacement complete?

--

Go to Step 9

--

12

Replace the MSM.

Is the replacement complete?

--

Go to Step 9

--

13
  1. Reconnect the MSM.
  2. Disconnect the TCM connector.
  3. Attempt to communicate with the other modules.

Does the scan tool communicate with the other modules?

--

Go to Step 11

Go to Step 14

14
  1. Reconnect the TCM.
  2. Disconnect the instrument cluster connector.
  3. Attempt to communicate with the other modules.

Does the scan tool communicate with the other modules?

--

Go to Step 15

Go to Step 16

15

Replace the instrument cluster.

Is the replacement complete?

--

Go to Step 9

--

16

Test the serial data circuit, of the DLC, for a short to ground between terminal 7 and each module.

    • ECM connector terminal 88
    • Instrument Cluster connector terminal 24
    • Memory Seat Module connector C1 terminal 6
    • TCM connector terminal 13

Did you find a short to ground in the serial data circuit?

--

Go to Step 17

Go to Step 18

17

Locate and repair the short to ground in the serial data circuit.

Is the repair complete?

--

Go to Step 9

--

18

Test the serial data circuit, of the DLC, for a short to voltage between terminal 7 and each module.

    • ECM connector terminal 88
    • Instrument Cluster connector terminal 24
    • Memory Seat Module connector C1 terminal 6
    • TCM connector terminal 13

Did you find a short to voltage in the serial data circuit?

--

Go to Step 19

Go to Step 2

19

Locate and repair the short to voltage in the serial data circuit.

Is the repair complete?

--

Go to Step 9

--