Circuit Description
Battery voltage is supplied to the power steering pump actuator terminal A when the EBCM commands the Electronic Brake Control Relay ON. Ground for the power steering pump actuator is provided through EBCM terminal 18 to actuator terminal B. The EBCM controls the amount of current supplied to the actuator based on input from the ABS wheel speed sensors and the steering wheel position sensor.
Conditions for Setting the DTC
| • | DTC C1273 can be set before ABS initialization or above 16 km/h (10 mph). |
| • | The EBCM detects the power steering pump actuator control circuit is open or shorted to ground before ABS initialization. |
| • | The actuator senses current less than half the command current when the vehicle is above 16 km/h (10 mph). |
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | ABS/VES is disabled. |
| • | The ABS warning indicator is turned ON and power steering returns to full assist. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used. |
| • | 100 drive cycles pass with no ABS DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF. |
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
| • | A poor connection |
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
| • | Open or short to ground in any of the EVO actuator circuit wires. |
| • | Malfunctioning power steering pump actuator. |
Use the enhanced diagnostic function of the scan tool in order to determine the frequency of the malfunction.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal-to-wiring connections |
| • | Physical damage to the wiring harness |
Diagnose and correct all ABS DTCs prior to clearing the VES DTCs. Clearing VES DTCs will automatically clear ABS DTCs resulting in a loss of DTC history data.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
|
Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual. | ||||
1 | Was the ABS Diagnostic System Check performed? | -- | Go to Step 2 | |
2 |
Is the feedback current greater than the specified value? | 100 mA | Go to Step 14 | Go to Step 3 |
3 |
Is the resistance within the specified range? | 0-2 ohms | Go to Step 4 | Go to Step 10 |
4 | Using the J 39200 , measure the resistance between the EBCM harness connector terminal 18 and ground. Is the resistance within the specified range? | OL (Infinite) | Go to Step 5 | Go to Step 11 |
5 | Using the J 39200 , measure the resistance between the actuator harness connector terminal A and the EBCM harness connector terminal C. Is the resistance within the specified range? | 0-2 ohms | Go to Step 6 | Go to Step 12 |
6 | Using the J 39200 , measure the resistance between the EBCM harness connector terminal C and ground. Is the resistance within the specified range? | OL (Infinite) | Go to Step 7 | Go to Step 13 |
7 |
Is the resistance within the specified range? | OL (Infinite) | Go to Step 8 | Go to Step 15 |
8 | Using the J 39200 , measure the resistance between the EBCM harness connector terminals 18 and C. Is the resistance within the specified range? | 7-19 ohms | Go to Step 9 | Go to Step 15 |
9 |
Replace any terminals with poor terminal contact or corrosion. Repair the damage if present. Is DTC C1273 set as a current DTC? | -- | Go to Step 16 | Go to Step 14 |
10 | Repair the open or high resistance in CKT 1295. Is the repair complete? | -- | -- | |
11 | Repair the short to ground in CKT 1295. Is the repair complete? | -- | -- | |
12 | Repair the open or high resistance in CKT 1633 or CKT 855. Is the repair complete? | -- | -- | |
13 |
Is the repair complete? | -- | -- | |
14 | The malfunction is intermittent. Refer to Diagnostic Aids. Is the action complete? | -- | -- | |
15 | Replace the Power Steering Pump Actuator. Refer to Variable Effort Steering Actuator Replacement . Is the repair complete? | -- | -- | |
16 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement Is the repair complete? | -- | -- | |
