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

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.

    • Electronic Brake Traction Control Module (EBTCM)
    • Heater and A/C Control
    • SIR Module

Does the scan tool communicate with the other modules?

--

Go to Step 10

Go to Step 4

3
  1. Disconnect the power steering control module (PSCM) connector.
  2. Measure the resistance between the PSCM connector terminal 1 and the data link connector (DLC) terminal 12.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 5

Go to Step 6

4
  1. Disconnect the EBTCM 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 1. 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 11

6

Locate and repair an open in CKT XM88 (BRN/WHT).

Is the repair complete?

--

Go to Step 9

--

7

Replace the EBTCM.

Is the replacement complete?

--

Go to Step 9

--

8
  1. Reconnect the EBTCM.
  2. Disconnect connector C1 from the heater and A/C control.
  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 PSCM.

Does the scan tool communicate with the PSCM?

--

System OK

Go to Step 11

10
  1. Inspect the FLASHER fuse for an open.
  2. Inspect and test the PSCM ignition feed circuit at terminal 6 for proper voltage with the KEY ON (11-13 V).
  3. Inspect and test the PSCM ground circuit (CKT F88) at terminal 8.
  4. Make necessary repairs.

Did you find and correct any conditions?

--

Go to Step 9

Go to Step 3

11

Replace the PSCM.

Is the replacement complete?

--

Go to Step 9

--

12

Replace the heater and A/C control.

Is the replacement complete?

--

Go to Step 9

--

13
  1. Reconnect the heater and A/C control.
  2. Disconnect the PSCM 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 PSCM.
  2. Disconnect the SIR module 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 SIR module.

Is the replacement complete?

--

Go to Step 9

--

16

Test the serial data circuit, of the DLC, for a short to ground between terminal 12 and each module.

    • EBTCM connector terminal 11
    • Heater and A/C Control connector C1 terminal 17
    • SIR Module terminal 12
    • PSCM connector terminal 1

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 12 and each module.

    • EBTCM connector terminal 11
    • Heater and A/C Control connector C1 terminal 17
    • SIR Module terminal 12
    • PSCM connector terminal 1

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

--