Circuit Description
With the vehicle at rest the lateral accelerometer voltage should be 2.5 volts. The scan tool will report lateral accelerometer as 2.5 volts. The sensor bias compensates for electronic signal errors, temperature changes, manufacturing differences and monitoring differences.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The vehicle speed is greater than 5 km/h (3 mph). |
Conditions for Setting the DTC
The lateral accelerometer input voltage is less than 1.17 volts or greater than 3.83 volts for more than 2 minutes.
Action Taken When the DTC Sets
| • | The code is displayed on the scan tool as DTC C0186. |
| • | The rear wheel steering system remains functional. |
Conditions for Clearing the DTC
| • | The conditions for the DTC are not currently present. |
| • | The rear wheel steering control module receives a clear code command from the scan tool. |
| • | The DTC clears after 100 malfunction free ignition cycles. |
Diagnostic Aids
| • | Inspect for poor connections at the harness connector of the rear wheel steering control module and Lat/Yaw sensor connector. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems. |
| • | Observe the rear wheel steering mode select switch. If all of the mode indicator LEDs are illuminated the rear wheel steering control module has lost its memory settings and the scan tool must be used to re-calibrate the rear wheel steering alignment data in the rear wheel steering control module. Refer to Wheel Alignment Measurement . |
| • | The system can have a DTC C0186 and 4-Wheel Steering will still function normally. |
Lateral Accelerometer Operating Parameters
| • | Proportional output voltage 0.25 to 4.75 volts |
| • | 0 lateral accel = 2.5 volts |
| • | Operating range is +/- 1.5 Gs |
| • | Sealed self contained unit two sensors in one housing |
Lateral Accelerometer
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Tests for the proper operation of the circuit in the high voltage range.
-
Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
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Tests for a short to ground in the 5 volt reference circuit.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform a Diagnostic System Check - Rear Wheel Steering? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the parameter is within the specified range? | 2.40-2.60 V | Go to Diagnostic Aids | Go to Step 3 |
Does the scan tool indicate that the parameter is greater than the specified value? | 4.85 V | Go to Step 4 | Go to Step 8 | |
Does the scan tool indicate that the parameter is less than the specified value? | 0.15 V | Go to Step 5 | Go to Step 9 | |
Does the scan tool indicate that the parameter is greater than the specified value? | 4.85 V | Go to Step 7 | Go to Step 6 | |
6 | Test the 5 volt reference circuit of the lateral accelerometer sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
7 | Test the 5 volt reference circuit of the lateral accelerometer sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 |
8 | Test the signal circuit of the lateral accelerometer sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
9 | Test the signal circuit of the lateral accelerometer sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 10 |
10 | Test the ground circuit of the lateral accelerometer sensor for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
11 | Inspect for poor connections at the harness connector of the lateral accelerometer sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 13 |
12 | Inspect for poor connections at the harness connector of the rear wheel steering control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 |
13 | Replace the Yaw rate sensor/Lateral Accerometer sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement in Rear Wheel Steering. Did you complete the replacement? | -- | Go to Step 15 | -- |
14 |
Important: Perform the Learn Alignment procedure. Refer to Wheel Alignment Measurement . Replace the rear wheel steering module. Refer to Rear Wheel Steering Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
