Scan Tool Does Not Communicate with Power Steering Control Module
WARNING: This page is about a different car, the 2000 Cadillac Catera. However, it is still accessible from the selected car via links, so may be relevant.
SCAN TOOL DOES NOT COMMUNICATE WITH POWER STEERING CONTROL MODULE
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Was the Data Link Communications Diagnostic System Check performed? | -- | Go to Step 2 | Diagnostic System Check - Data Link Communications |
| 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 20 |
| 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 TESTING FOR INTERMITTENTS & POOR CONNECTIONS 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 | -- |
| 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 | 1. Disconnect each module on the serial data circuit (DLC terminal 12). 2. Test the serial data circuit, of the DLC, for a short to ground. 3. Test between terminal 12 and the following terminals at 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. (Turn ON the ignition, leaving the engine OFF, when testing for a short to voltage.) * 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 21 |
| 19 | Locate and repair the short to voltage in the serial data circuit. Is the repair complete? |
-- | Go to Step 9 | -- |
| 20 | 1. Turn Off the ignition. 2. Disconnect the scan tool from the data link connector (DLC). 3. Inspect for poor connections/terminal tension at the DLC terminal 12. Refer to TESTING FOR INTERMITTENTS & POOR CONNECTIONS Did you find and correct a poor connection condition? |
-- | Go to Step 2 | Go to Step 4 |
| 21 | Test the serial data circuit, of the DLC, for an open 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 an open in the serial data circuit? |
-- | Go to Step 9 | -- |