DTC 245

EBB.Code (DTC) 2-4-5

2-4-5 Break or short-circuit to ground in torque-limiting circuit

DTC information

Conditions for DTC







The engine torque is reduced to allow smoother shifting in some gear changes, and to minimize transmission wear. The limiting process is controlled by signals (TC1/TC2) sent from the transmission control module (TCM) to the engine control module ECM. Receipt confirmation signal (TCM) is sent from engine control module (ECM) to the TCM. The signal indicates that torque limiting is taking place. The ECM adjusts the ignition to a lower level and the engine torque is reduced. If the TCM fails to register an acknowledgement signal after request for torque limiting, DTC 2-4-5 is set.


Substitution value

Control Module GROUP I:
No substitution value

Control Module GROUP II:
The transmission control module (TCM) "Emergency mode II" program is initiated.


Defect cause

- Break in the signal wiring TC1 ,TC2 and TCM
- Signal wiring TC1, TC2 and TCM short-circuited to ground or supply
- Contact resistance in connections.


Fault symptom

- Jerky gear shifting due to maximum system pressure in the transmission and no engine torque reduction
- No Lock-Up operational.
- Fault-tracing starts with EBB1.




EBB1

Checking TC1, TC2 and TCM signal wiring resistance to ground






- Ignition OFF
- Connect test box and check ground points as per GB1-GB2 GB. Connecting the Test Box

- TCM disconnected.

NOTE: Motronic 4.3 MFI control module only: Wait approx. 150 seconds.

- Disconnect engine control module (ECM Fenix 5.2. EZ129K or Motronic 4.3 MFI control modules).

Connect ohmmeter between test box terminals #20
(#A20) and:







- #32 (#B2) TC1
- #33 (#B3) TC2
- #34 (#84) TCM

The ohmmeter should read infinite resistance.

If reading is OK:
- Checking signal wiring resistance EBB2.

If reading is incorrect:
- Check wiring between TCM #B2 (TC1), #B3 (TC2) or #B4 (TCM) and ECM (Fenix 5.2, EZ129K or Motronic 4.3) #B2 (TC1), #B3 (TC2) or #B4 (TCM) for short circuit to ground as per FA3. FA. Checking Wiring and Connections




EBB2

Checking signal wiring resistance






- Ignition OFF
- Transmission control module (TCM) disconnected
- Connect a test box to the engine control module ECM (MFI Fenix 5.2, EZ129k or or Motronic 3.2).
- Engine Control Module (ECM) disconnected. Connect an ohmmeter between the transmission test box terminal:







- #32 (#B2) TC1 and terminal #2 (#B2) for the ECM test box
- #33 (#B3) TC2 and terminal #3 (#B3) for the ECM test box
- #34 (#B4) TCM and terminal #4 (#B4) for the ECM test box

NOTE: Equivalent for EZ129k are #B2, #B3 and #B4 terminal #32 (#B2), #33 (#B3) and #34 (#B4) on the test box.

The ohmmeter should read approx. 0 Ohms.

If reading is OK:
- Checking TC1 signal wiring for short circuit to battery voltage EBB3.

If reading is incorrect
- Check wiring between TCM #B2 (TC1), #B3 (TC2) or #B4 (TCM) and ECM (Fenix 5.2, EZ129K, Motronic 4.3) #B2 (TC1), #B3 (TC2) or #B4 (TCM) for breaks as per FA2. FA. Checking Wiring and Connections



EBB3

Checking TC1 signal wiring for short circuit to battery voltage







- Ignition OFF
- Connect the transmission control module (TCM) and the engine control module (ECM) or modules.
- Ignition ON.

Connect a voltmeter between transmission test box #20 (#B20) and #32 (#B2)

The voltmeter should register:

- Control Modules GROUP I: approx 5.0 V
- Control Modules GROUP II: approx. 1-2 V below battery voltage.

If reading is OK:
- Checking TC2 signal wiring for short circuit to battery voltage EBB4.

If reading is incorrect:
- Check the cable between the TCM #B2 and the ECM #B2 for short circuit to supply as per FA4. FA. Checking Wiring and Connections



EBB4

Checking TC2 signal wiring for short circuit to battery voltage







- Ignition ON.

Connect an voltmeter between transmission test box #20 (#B20) and #33 (#B3)
The voltmeter should register:

- Control Modules GROUP I: approx 5.0 V
- Control Modules GROUP II: approx. 1-2 V below battery voltage.

If reading is OK:
- Checking TCM signal wiring for short circuit to battery voltage EBB5.

If reading is incorrect:
- Check the cable between the TCM #B3 and the ECM #B3 for short circuit to supply as per FA4. FA. Checking Wiring and Connections



EBB5

Checking TCM signal wiring for short circuit to battery voltage






- Ignition ON.

Connect a voltmeter between transmission test box #20 (#A20) and #34 (#B4)
The voltmeter should register:

- Control Modules GROUP I
EZ129K: approx. 5.0 V
Fenix 5.2: 9-10 V

- Control Modules GROUP II
Fenix 5.2: approx 1.5 V below battery voltage
Motronic 4.3: approx. 2.0 V below battery voltage


If reading is OK:
- Checking request on TC1 signal wiring EBB6.

If reading is incorrect:
- Check the cable between the TCM #B4 and the ECM #B4 for short circuit to supply as per FA4. FA. Checking Wiring and Connections




EBB6

Checking request on TC1 signal wiring






- Ignition ON

Connect a voltmeter between transmission test box #20 (#A20) and #32 (#B2)
The voltmeter should register:

- Control Modules GROUP I: approx 5.0 V
- Control Modules GROUP II: approx. 1-2 V below battery voltage.

Check TC1 operation using Diagnostic Test Mode 4. Diagnostic Test Mode 4 The voltmeter should deflect down to approx. 0 V when the signal is activated. (The deflection is rapid, approx. 1 second)

If the voltage reading deflects:
- Checking request on TC2 signal wiring EBB7

If the voltage did not deflect:
- Try a new TCM as per AB1-AB4.


EBB7

Checking request on TC2 signal wiring






- Ignition ON.

Connect voltmeter between transmission test box #20 (#A20) and #33 (#B3)
The voltmeter should register:

- Control Modules GROUP I: approx 5.0 V
- Control Modules GROUP II: approx. 1.2 V below battery voltage

Check TC2 operation using Diagnostic Test Mode 4. Diagnostic Test Mode 4 The voltmeter should deflect down to approx. 0 V when the signal is activated. (The deflection is rapid, approx. 1 second)

If the voltage reading deflects:
- Checking TCM acknowledge signal from engine control module ECM EBB8.

If the voltage did not deflect:
- Try a new TCM as per AB1 - AB4.



EBB8

Checking TCM acknowledge signal from engine control module (ECM)






- Ignition ON.

Connect a voltmeter between transmission test box #20 (#A20) and #34 (#B4)
The voltmeter should register:

- Control Modules GROUP I
EZ129k: approx. 5.0 V
Fenix 5,2: 9-10 V

- Control Modules GROUP I
Fenix 5.2: approx 1.5 V below battery voltage
Motronic 4.3: approx. 2 V below battery voltage

Check TCM acknowledge signal operation using Diagnostic Test Mode 4. Diagnostic Test Mode 4 Activate TC1 or TC2 so the ECM sends an acknowledge signal (TCM) to the TCM. The voltmeter should deflect down to approx. 0 V when the signal is activated. (The deflection is rapid, approx. 1 second)

If the voltage reading deflects:
- Intermittent fault. Fault-tracing as per EBB9.

If the voltage did not deflect:
- Try with a new engine control module ECM (MFI Fenix 5.2, EZ129K or Motronic 4.3).






EBB9

Intermittent fault Checking wiring and connections

- Check the connector to the transmission control module (TCM) and the engine control module connector for loose connections as per FA5, and contact resistance and oxidation as per FA6. FA. Checking Wiring and Connections

- Check the cable between the TCM #B2 and the ECM #B2 for intermittent break as per FA2, intermittent short circuit to ground as per FA3 and intermittent short circuit to supply as per FA4. FA. Checking Wiring and Connections

- Check the cable between the TCM #B3 and the ECM #B3 for intermittent break as per FA2, intermittent short circuit to supply as per FA4 and intermittent short circuit to ground as per FA3. FA. Checking Wiring and Connections

- Check the cable between the TCM #B4 and the ECM #B4 for intermittent break as per FA2, intermittent short circuit to supply as per FA4 and intermittent short circuit to ground as per FA3. FA. Checking Wiring and Connections