Test Description
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.
The number(s) below refer to the step number(s) on the diagnostic table. No information has been left out.
- 2. A DTC U2100 set in either the ECM, TCM or EBTCM may have caused U2103 to set. You must diagnose and clear DTC U2100 to determine if it is the cause of U2103 setting.
- 3. A U2105, U2106 or U2108 DTC with a history status may indicate the cause of U2103
- 4. The module(s) which are not communicating data is the likely cause of U2103 being set.
- 8. The module(s) which was not communicating data due to a poor connection to the CAN Bus circuit may have set other CAN Bus codes for the bus or modules that it was monitoring
- 10. The modules which can communicate indicate the module which cannot communicate. You must clear the DTC from these modules to avoid future misdiagnosis
- 12. If all modules are communicating, the module which set U2103 may have done so due to some other condition
- 13. The module which set U2103 is the likely cause of the malfunction
DTC U2103 FEWER CONTROLLERS ON BUS THAN PROGRAMMED
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Was the Diagnostic System Check performed for one of the following modules? ECM BCTM TCM |
-- | Go to Step 2 | Go to the Applicable Diagnostic System Check |
| 2 | Was DTC U2100 recorded as a history or current DTC in the ECM, TCM or EBTCM? | -- | Go to DTC U2100 CAN-BUS Communication Malfunction and perform the diagnostics for the DTC | Go to Step 3 |
| 3 | Were any of the following DTCs recorded with a history status? * DTC U2105 * DTC U2106 * DTC U2108 |
-- | Go to testing in this article and perform the diagnostics for the applicable DTC | Go to Step 4 |
| 4 | 1. Turn the Ignition switch to the ON position, engine running. 2. Using the scan tool, observe the following data displays: * Engine Data Display * Transmission Data Display * ABS Data Display 3. Observe the data parameters listed in the Diagnostic Aids for missing data. Is any module on the CAN Bus not receiving data? |
-- | Go to Step 5 | Go to Step 12 |
| 5 | 1. Disconnect the connector from the module that set DTC U2103. 2. Inspect the connector for the following: * poor terminal contact * Corrosion * Damage 3. Refer to TESTING FOR INTERMITTENTS & POOR CONNECTIONS Did you find and correct the condition? |
-- | Go to Step 8 | Go to Step 6 |
| 6 | 1. Disconnect the connector(s) from the module(s) that are not communicating data on the CAN Bus. 2. Inspect the connector(s) for the following: * poor terminal contact * Corrosion * Damage 3. Refer to TESTING FOR INTERMITTENTS & POOR CONNECTIONS . Did you find and correct the condition? |
-- | Go to Step 8 | Go to Step 7 |
| 7 | Replace the Module(s) which are not communicating data. Refer to POWERTRAIN CONTROL MODULE
or TRANSMISSION CONTROL MODULE
Replacement or ELECTRONIC BRAKE TRACTION CONTROL MODULE (EBTCM)
Replacement in Antilock Brake System Did you complete the replacement? |
-- | Go to Step 10 | -- |
| 8 | 1. Reconnect all connectors. 2. Install a scan tool. 3. Turn the ignition switch to the ON position, engine off. 4. Select the Display DTCs function of the module(s) which was not communicating data. Does the scan tool display any DTCs other than the following? * U2100 * U2103 * U2104 * U2105 * U2106 * U2108 |
-- | Go to DTC INDEX | Go to Step 9 |
| 9 | Clear DTCs using the Scan Tool Did you complete the action? |
-- | Go to Step 10 | -- |
| 10 | 1. Install a scan tool if not previously installed. 2. Turn the ignition switch to the ON position. 3. Select the Display DTCs function of the module(s) which had U2103 set as a current DTC. Does the scan tool display any DTCs other than the following? * U2100 * U2103 * U2104 * U2105 * U2106 * U2108 |
-- | Go to DTC INDEX | Go to Step 11 |
| 11 | Clear DTCs using the scan tool. Did you complete the action? |
-- | System OK | -- |
| 12 | Did you record any other DTCs for the module(s) which had U2103 set as a current DTC? | -- | Go to DTC INDEX | Go to Step 13 |
| 13 | 1. Install a scan tool. 2. Turn the ignition switch to the ON position, engine off. 3. Clear DTCs using the scan tool. 4. Turn the ignition to the OFF position for at least 5 seconds. 5. Turn the ignition to the ON position, engine off. 6. Select the Display DTCs function. Does the scan tool display DTC U2103 as a current DTC? |
-- | Go to Step 14 | System OK |
| 14 | Replace the module which had DTC U2103 set as a current DTC. Refer to POWERTRAIN CONTROL MODULE
or TRANSMISSION CONTROL MODULE
Replacement or ELECTRONIC BRAKE TRACTION CONTROL MODULE (EBTCM)
Replacement Did you complete the replacement? |
-- | System OK | -- |