GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 DTC 🢒 DTC B2878 Tilt Down Switch Circuit Malfunction

Object Number: 106568 Size: MF
Tilt Wheel/Column Components
Cell 49 - Power, Ground, Switch, Sensors and Motors
Handling ESD Sensitive Parts Notice

Circuit Description

The steering column tilt/telescoping module (TTM) receives a input from the tilt/telescope switch when the switch is actuated. When the switch is moved to the DOWN position, battery positive (B+) is pulled low. The TTM recognizes this input and tilts the steering column down.

Conditions for Setting the DTC
    •  When the tilt/telescope switch is active for 30 seconds after motion has ceased, the module considers the switch shorted and sets the DTC.
    •  If DTC B2860 or B2862 is current and the tilt/telescope switch is active for 30 seconds, the module considers the switch shorted and sets the DTC.

Action Taken When the DTC Sets
    • The TTM will no longer tilt the steering column down.
    • The TTM will continue to respond to valid inputs from the other manual switches.
    • All memory recall function commands will ignored for all directions.

Conditions for Clearing the DTC
    • The TTM determines that the tilt/telescope switch is no longer active.
    • Use the On-Boards clearing DTCs feature.
    • Use a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. Perform the Tilt/Telescoping Steering Column Diagnostic System Check before continuing with the diagnosis of this DTC.

    2.

  2. Determines whether the failure is in the steering column tilt/telescoping module (TTM) or the tilt/telescope switch.

    3.

  3. Clear all DTCs after the repair procedure is complete.

DTC B2878 -- Tilt Down Switch Failed

Step

Action

Value(s)

Yes

No

1

Was the Tilt/Telescoping Steering Column Diagnostic System Check performed?

--

Go to Step 2

Go to Tilt/Telescoping Steering Column Diagnostic System Check

2

  1. Turn OFF the ignition switch.
  2. Disconnect the TTM connector C4.
  3. Connect a scan tool to the data link connector (DLC).
  4. Using the scan tool, clear all DTCs.

After 30 seconds, does DTC B2878 reset?

--

Go to Step 4

Go to Step 3

3
  1. Check the steering column tilt/telescoping module connector C4 for poor terminal contact.
  2. If OK, replace the steering column tilt/telescoping module. Refer to Tilt/Telescoping Module Replacement .

Is the replacement complete?

--

Go to Step 5

--

4

Replace the tilt/telescope switch.

Is the replacement complete?

--

Go to Step 5

--

5

  1. Turn OFF the ignition switch.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition switch.
  4. Clear any DTCs.
  5. Repeat the Diagnostic System Check. Refer to Tilt/Telescoping Steering Column Diagnostic System Check .

Is the Diagnostic System Check complete?

--

System OK

--