Refer to Engine Controls Schematics
Automatic Transaxle, EBCM, Performance Shift Switch and Stop Lamp Switch
.
Circuit Description
The traction control system uses the antilock brake system in conjunction with the PCM fuel and ignition controls in order to limit the drive wheel slippage during acceleration. The PCM controlled portion of the traction control system reduces the engine torque by any or all of the following methods:
| • | Retarding the spark timing |
| • | Altering the air-to-fuel ratio |
| • | Altering the boost PWM, VIN 1 |
| • | Shutting OFF up to 3 injectors |
In order to determine the required amount of torque reduction , the PCM monitors the traction control system (TCS) desired torque pulse width modulation (PWM) signal from the electronic brake and traction control module (EBTCM). The PCM also provides a TCS delivered torque PWM that informs the electronic brake and traction control module (EBTCM) how much torque the engine produces. The Desired Torque display on the scan tool indicates the amount of engine torque that the EBTCM requests. With traction control not active, the Desired Torque should vary between 99 percent and 100 percent. The Desired Torque display on the scan tool is not the PWM duty cycle.
Conditions for Setting the DTC
| • | The desired torque signal PWM duty cycle is less than 5 percent or more than 95 percent. |
| • | The conditions exists for up to 10 seconds |
Action Taken When the DTC Sets
The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.
Conditions for Clearing the MIL/DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction free warm-up cycles. |
| • | The PCM receives a clear code command from the scan tool. |
Diagnostic Aids
An intermittent may be caused by a poor connection, rubbed-through wire insulation, or a broken wire inside the insulation. Inspect for the following conditions:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 |
Is the Traction Control Desired Torque at or near the specified value? | 100% | ||
3 |
Is the voltage at the specified value? | 5V | ||
4 |
Is the frequency between the specified values? | 120 Hz and 135 Hz | ||
5 |
Is the duty cycle between the specified values? | 5 and 95 % | ||
6 |
Did you find and correct the condition? | -- | ||
7 |
Did you find and correct the condition? | -- | ||
8 | Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement in Antilock Brake System. Did you complete the replacement? | -- | -- | |
9 |
Did you find and correct the condition? | -- | ||
10 |
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | |
11 |
Is the (Traction Control) Desired Torque at or near the specified value? | 100% | System OK |
