GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 DTC 🢒 DTC B1656 EEPROM Write Error

Circuit Description

The steering column tilt/telescoping module (TTM) performs internal tests on the EEPROM each time that the module performs a write function to a memory address in the EEPROM. The TTM reads back the data that has been written and compares it to the data. If the data does not match after three consecutive write and verify attempts, the TTM will indicate a write malfunction is current.

Conditions for Setting the DTC
    • The data read back after a write does not match the data being written three consecutive times.
    • The TTM detects an internal write malfunction.
    • The condition must occur when data is being written.

Action Taken When the DTC Sets
    • Stores a DTC B1656 in the TTM memory.
    • No driver warning message will be displayed for this DTC.
    • The TTM will store the value being written in another memory address in the EEPROM.

Conditions for Clearing the DTC
    • This DTC requires a successful write in order to change from current to history.
    • The TTM no longer detects an internal write malfunction.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use the On-Boards clearing DTCs feature.
    • Use a scan tool.

Diagnostic Aids

Since the EEPROM cannot be removed from the TTM and DTC B1656 is an internal TTM malfunction, the TTM may be replaced. Refer to diagnostic table.

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. Clear all DTCs and cycle ignition to check that the DTC did not falsely set.

    3.

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

DTC B1656 TTM -- EEPROM Write Error

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 ON the ignition switch.
  2. Clear any DTCs. Refer to Clearing DTCs.
  3. Turn OFF the ignition switch.
  4. Turn ON the ignition switch.

Is the DTC still present?

--

Go to Step 3

System OK

3

Replace the steering column tilt/telescoping module. Refer to Tilt/Telescoping Module Replacement .

Is the replacement complete?

--

Go to Step 4

--

4

  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

--