Circuit Description
The variable effort steering (VES) system uses the speed sensitive power steering (SSPS) control module to control current to an electromagnetic rotary actuator. The SSPS control module commands current from 0.50-1.05 amperes to the actuator. At low speeds, approximately 1 ampere of current is commanded, which provides full power assist. At medium speeds, 0.78-0.90 amperes of current is commanded and moderate steering is provided. At high speeds, the SSPS control module will command a current between 0.50-0.77 amperes, which provides minimal steering assist. The lower the commanded current, the less power steering assist is provided.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C2203 Steering Assist Control Actuator Circuit
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
One of the following conditions exist in the VES actuator or in the circuits to the actuator:
| • | An open circuit |
| • | A short to ground |
| • | A short to voltage |
Action Taken When the DTC Sets
| • | The SSPS warning light will illuminate. |
| • | Power steering assist will default to partial steering assist. |
| • | A DTC C2203 is stored in memory. |
Conditions for Clearing the DTC
| • | The SSPS warning lamp will turn OFF when conditions for the fault are no longer present. |
| • | Use a scan tool in order to clear the DTC. |
Diagnostic Aids
Check for the following conditions if a history or intermittent DTC is indicated.
| • | A poor connection at the SSPS control module. Inspect the harness connectors for backed out terminals, improper mating, improperly formed or damaged terminals, and poor terminal to wire connections. |
| • | A damaged wiring harness. Inspect the wiring harness for damages. If the wiring harness appears to be in good condition, observe the display on the DMM while moving the connectors and wiring harnesses related to the circuits. A change in the DMM display during the test will indicate the location of the fault. |
| • | For additional information, refer to Testing for Intermittent Conditions and Poor Connections . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Tests if the Commanded Current parameter is at the specified value in the active state.
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Tests if the resistance of the VES actuator is in the specified range.
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Tests the high effort control circuit for an open or short to voltage
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Tests the low effort control circuit for a short to ground
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Tests for poor connections at the VES actuator harness connector.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Steering Assist Schematics Connector End View Reference: Steering Assist Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Does the scan tool indicate that the SSS Commanded Current parameter is within specified range? | 0.95-1.05 A | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | |
Does the resistance measure within the specified range? | 5.5-6.5 ohms | Go to Step 4 | Go to Step 10 | |
4 | Test the VES actuator and actuator harness for a short to ground. Refer to Testing for Short to Ground . Was a short to ground located? | -- | Go to Step 5 | Go to Step 6 |
5 | Visually inspect the actuator harness for any cut, chaffed or damaged wires. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
6 | Test the high effort control circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 7 |
Test the high effort control circuit of the VES actuator for an open or short to voltage. Refer to Circuit Testing and Testing for a Short to Voltage . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 | |
Test the low effort control circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 | |
9 | Test the low effort control circuit of the VES actuator for an open or short to voltage. Refer to Circuit Testing and Testing for a Short to Voltage . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
Inspect for poor connections at the harness connector of the VES actuator. Refer to Testing for Intermittent Conditions and Poor Connections . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 | |
11 | Inspect for poor connections at the harness connector of the SSPS control module. Refer to Testing for Intermittent Conditions and Poor Connections . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the VES actuator. Refer to Steering Gear Replacement . Did you complete the repair? | -- | Go to Step 14 | -- |
13 | Replace the power steering control module. Refer to Power Steering Control Module Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
14 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
