Circuit Description
The EBCM/EBTCM controls a bi-directional magnetic rotary solenoid. The solenoid is in the steering gear. The solenoid adjusts the amount of power steering assist in order to achieve a given level of driver effort in turning the vehicle. The EBCM/EBTCM varies the steering assist by adjusting the current flow through the solenoid. The amount of steering assist adjusted for steering is dependent upon vehicle speed. As the vehicle speed increases, the following actions occur:
| • | The steering assist decreases |
| • | The driver effort increases. |
As the vehicle speed decreases, the following actions occur:
| • | The steering assist increases |
| • | The driver effort decreases. |
The EBCM/EBTCM detects an open or a short in the steering circuit by comparing feedback current to the commanded current. If the feedback current is less than 360 mA while the absolute value of the commanded current is greater than 826 mA for 0.5 seconds, a fault is present.
Conditions for Setting the DTC
All of the following conditions occur:
| • | The ignition is ON. |
| • | The EBCM/EBTCM detects one of the following conditions: |
| - | An open |
| - | A short to ground |
| - | A short to voltage |
Actions Taken When the DTC Sets
| • | A malfunction DTC is stored. |
| • | The variable effort steering is disabled. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and you used the scan tool Clear DTC function. |
| • | The EBCM/EBTCM does not detect the DTC in 50 drive cycles. |
Diagnostic Aids
| • | 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. |
| • | An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation. |
| • | If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Variable Effort Steering System Check? | -- | Go to Step 2 | |
2 | Inspect the wiring and the connectors for damage. Is physical damage evident? | -- | Go to Step 3 | Go to Step 4 |
3 | Repair damage to the wiring and connectors. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
4 |
Is the resistance within the specified range? | 1.6-3.1 ohms | Go to Step 19 | Go to Step 5 |
5 |
Is the resistance within the specified range? | 1.6-3.1 ohms | Go to Step 6 | Go to Step 12 |
6 | Use a J 39200 DMM in order to measure the resistance between the J 39700 terminal C and the variable steering actuator connector terminal A. Is the resistance less than the specified value? | 0.5 ohms | Go to Step 7 | Go to Step 13 |
7 | Use a J 39200 DMM in order to measure the resistance between the J 39700 terminal F and the variable steering actuator connector terminal B. Is the resistance less than the specified value? | 0.5 ohms | Go to Step 8 | Go to Step 14 |
8 | Use a J 39200 DMM in order to measure the resistance between the J 39700 terminal F and a good ground. Is the resistance less than the specified value? | OL | Go to Step 15 | Go to Step 9 |
9 | Use a J 39200 DMM in order to measure the voltage between the J 39700 terminal F and a good ground. Is the voltage greater than the specified value? | 1 V | Go to Step 16 | Go to Step 10 |
10 | Use a J 39200 DMM in order to measure the resistance between the J 39700 terminal C and a good ground. Is the resistance less than the specified value? | OL | Go to Step 17 | Go to Step 11 |
11 | Use a J 39200 DMM in order to measure the voltage between the J 39700 terminal C and a good ground. Is the voltage greater than the specified value? | 1 V | Go to Step 18 | Go to Step 19 |
12 | Replace the variable steering actuator. Refer to Steering Gear Replacement in Power Steering System Did you complete the repair? | -- | -- | |
13 | Repair the open in CKT 1787 (GRY). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
14 | Repair the open in CKT 345 (WHT). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
15 | Repair the short to ground in CKT 345 (WHT). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
16 | Repair the short to voltage in CKT 345 (WHT). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
17 | Repair the short to ground in CKT 1787 (GRY). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
18 | Repair the short to voltage in CKT 1787 (GRY). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
19 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement in Antilock Brakes System. Did you complete the repair? | -- | -- |
