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For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Century (China) (CNG) 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1254 Abnormal Shutdown Detected

Object Number: 393791 Size: MF
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

When EBCM/EBTCM relay is activated (turned on) voltage is supply to valve solenoids and pump motor. This DTC identifies a malfunction with the EBCM/EBTCM loosing ground or battery, or when battery is disconnected while running.

Conditions for Setting the DTC

DTC C1254 is set when an running reset occurs. A running reset is when the vehicle is running and functions are normal then suddenly a loss of power or ground connection occurs to the EBCM/EBTCM.

Action Taken When the DTC Sets
    • A malfunction DTC is stored.
    • ABS/TCS is disabled.
    • ABS/TCS Indicators are turned on.
    • Magnetic Steering Variable Assist (MSVA) is disabled.
    • TIM goes into Autolearn mode after system recovery.

Conditions for Clearing the DTC
    • Condition for DTC is no longer present and scan tool clear DTC function is used.
    • 100 ignition cycles have passed with no DTCs detected.

Diagnostic Aids
    • Possible causes for DTC C1254 to set are:
       - Running reset occurred.
       - Loss of EBCM/EBTCM ground.
       - Sudden drop in voltage.
       - Poor or loose grounds connections.
       - Poor or loose power connections.
       - Battery disconnected due to corrosion or loose battery terminals.
       - Internal EBCM/EBTCM malfunction.
    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • If an intermittent malfunction exists refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - ABS

2
  1. Turn the ignition switch to the RUN position, engine off.
  2. Using a DMM, measure the voltage at the ABS Fuse (60A) by probing between the fuse test terminals and a good ground.

Is the voltage within the range specified within the value(s) column?

10.5-14.0 V

Go to Step 3

Go to Power Distribution Schematics

3
  1. Turn the ignition switch to the RUN position, engine off.
  2. Using a DMM, measure the voltage at the ABS Fuse (10A) by probing between the fuse test terminals and a good ground.

Is the voltage within the range specified within the value(s) column?

10.5-14.0 V

Go to Step 4

Go to Power Distribution Schematics

4
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the EBCM/EBTCM connector.
  3. Connect the Universal Pinout Box using the J 39700-99 Cable Adapter to the EBCM/EBTCM harness connector only.
  4. Using DMM, measure the resistance between terminal C of J 39700 Universal Pinout Box and a known good ground.
  5. Perform a wiggle test on the wiring harness while measuring resistance.

Is the resistance within the range specified in the value(s) column?

0 - 2 ohms

Go to Step 6

Go to Step 5

5

Repair CKT 251A for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

6
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the EBCM/EBTCM connector.
  3. Connect the Universal Pinout Box using the J 39700-99 Cable Adapter to the EBCM/EBTCM harness connector only.
  4. Using DMM, measure the resistance between terminal D of J 39700 Universal Pinout Box and a known good ground.
  5. Perform a wiggle test on the wiring harness while measuring resistance.

Is the resistance within the range specified in the value(s) column?

0 - 2 ohms

Go to Step 8

Go to Step 7

7

Repair CKT 251B for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

8
  1. Turn the ignition switch to the RUN position, engine off.
  2. Using a DMM, measure the voltage between terminals A11 and C of J 39700 Universal Pinout Box.
  3. Perform a wiggle test on the wiring harness while measuring voltage.

Is the voltage within the range specified in the value(s) column?

10.0-14.0 V

Go to Step 10

Go to Step 9

9

Repair CKT 1339 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

10
  1. Turn the ignition switch to the RUN position, engine off.
  2. Using a DMM, measure the voltage between terminals A and C of J 39700 Universal Pinout Box.
  3. Repeat the previous step measuring for voltage between terminals B and C of J 39700 Universal Pinout Box.
  4. Perform a wiggle test on the wiring harness while measuring voltage.

Is the voltage within the range specified in the value(s) column?

10.0-14.0 V

Go to Step 12

Go to Step 11

11

Repair CKTs 1442A or 1142B for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

12
  1. Turn the ignition switch to the OFF position.
  2. Inspect the following components:
    3. • The EBCM/EBTCM
    • The EBCM/EBTCM harness connector
    • The battery and connections
    • The engine ground connections
  3. Inspect the above components for signs of the following conditions:
    4. • Poor terminal contact
    • Damage terminals
    • Terminal corrosion

Are there any signs of poor terminal contact, corrosion or damage terminal(s)?

--

Go to Step 13

Go to Step 14

13

Replace or repair all of the terminals and/or connectors that exhibit signs of poor terminal contact, corrosion or damage terminal(s).

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

14
  1. Reconnect all system components.
  2. Install a scan tool to the data link connector.
  3. Select Ignition Voltage and Switched Battery Voltage in the ABS Data Display.
  4. Crank the engine with ignition circuit disabled.
  5. Monitor both the Ignition Voltage and Switched Battery Voltage in the ABS Data Display.

Does the Ignition Voltage and Switched Battery Voltage stay within the range specified in the value(s) column?

10.0-14.0 V

Go to Step 16

Go to Step 15

15

Repair the intermittent concern causing the Ignition Voltage or Switched Battery Voltage to drop below the specified value during cranking. Carefully inspect for the following:

    • Poor terminal contact
    • Damage terminals
    • Terminal corrosion
    • Battery and engine ground connections
    • Junction block connections

--

Go to Diagnostic System Check - ABS

--

16
  1. Scan tool still connected to the data link connector.
  2. Ignition Voltage and Switched Battery Voltage still selected in the ABS Data Display.
  3. Test drive the vehicle monitoring both the Ignition Voltage and Switched Battery Voltage in the ABS Data Display.

Does the Ignition Voltage and Switched Battery Voltage stay within the range specified in the value(s) column?

10.0-14.0 V

Go to Step 18

Go to Step 17

17

Repair the intermittent concern causing the Ignition Voltage or Switched Battery Voltage to drop below the specified value during driving. Carefully inspect for the following:

    • Poor terminal contact
    • Damage terminals
    • Terminal corrosion
    • Battery and engine ground connections
    • Junction block connections

--

Go to Diagnostic System Check - ABS

--

18

Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module/Electronic Brake and Track Control Module Replacement .

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

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