DTC C0040 RF Wheel Speed Circuit Malfunction No Signal
Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBTCM uses the frequency from to calculate the wheel speed.
Conditions for Setting the DTC
The DTC can be set any time the ignition is in the RUN position and the EBTCM detects an open or a short to voltage.
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | The ABS/TCS disables. |
| • | The amber ABS/TC indicator(s) turn on. |
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 ignition cycles pass with no DTC(s) detected. |
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. |
| • | Thoroughly inspect any circuitry that may be causing the 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 |
| • | The following conditions may cause an intermittent malfunction: |
| - | A poor connection |
| - | Rubbed-through wire insulation |
| - | A broken wire inside the insulation |
| • | If the customer's comments reflect that the amber ABS/TCS indicator is on only during moist environmental conditions (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure: |
| 1. | Spray the suspected area with a five percent saltwater solution. |
Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution.
| 2. | Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at least 30 seconds. |
| 3. | If the DTC returns, replace the suspected harness. |
| • | If an intermittent malfunction exists refer to Intermittents and Poor Connections Diagnosis in Wiring Systems for further diagnosis. |
Test Description
The numbers below refer to step numbers on the diagnostic table.
-
This step checks for an open in the WSS or WSS CKT.
-
Checks for a short to voltage in the WSS CKT.
-
Checks for a short to voltage in the WSS CKT.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | ||
2 | Inspect the WSS for physical damage. Is physical damage of the WSS evident? | -- | ||
3 | Replace the WSS. Refer to Wheel Speed Sensor Replacement . Is the replacement complete? | -- | -- | |
Is the resistance within the range specified in the value(s) column? | 800-1700ohms | |||
5 |
Is the resistance within the range specified in the value(s) column? | 800-1700ohms | ||
6 | Using J 39200 DMM, measure the resistance between terminal 5 of J 39700 and terminal 1 of the WSS harness connector. Is the resistance within the range specified in the value(s) column? | 0-5ohms | ||
7 | Repair CKT PU251 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
8 | Using J 39200 DMM, measure the resistance between terminal 4 of J 39700 and terminal 2 of the WSS harness connector. Is the resistance within the range specified in the value(s) column? | 0-5ohms | ||
9 | Repair CKT XU251 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
10 | Malfunction is intermittent. Inspect all connectors and harnesses for damage that may result in an open or high resistance when connected. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
Is the voltage within the range specified in the value(s) column? | Above 1V | |||
12 | Repair CKT PU251 for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
Using J 39200 DMM, measure the voltage at terminal 4 of J 39700 . Is the voltage within the range specified in the value(s) column? | Above 1V | |||
14 | Repair CKT XU251 for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
15 | Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the replacement complete? | -- | -- | |
16 |
Does the DTC reset as a current DTC? | -- |
DTC C0040 RF Wheel Speed Circuit Malfunction Invalid Signal
Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBTCM uses the frequency from to calculate the wheel speed.
Conditions for Setting the DTC
| • | The DTC will set if one wheel speed = 0 and the other WSS are greater than 40 Km/h (25 mph) for 10 ms. |
| • | The DTC will set if during drive off, one wheel speed = 0, and the other WSS are greater than 12 Km/h (7.5 mph). |
| • | The EBTCM detects a short to ground. |
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | The ABS/TCS disables. |
| • | The amber ABS/TCS indicator(s) turn on. |
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 ignition cycles pass with no DTC(s) detected. |
Diagnostic Aids
| • | Inspect the wheel speed sensor and wheel speed sensor ring for improper mounting or physical damage. |
| • | 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. |
| • | Thoroughly inspect any circuitry that may be causing the 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 |
| • | The following conditions may cause an intermittent malfunction: |
| - | A poor connection |
| - | Rubbed-through wire insulation |
| - | A broken wire inside the insulation |
| • | If the customer's comments reflect that the amber ABS/TCS indicator is on only during moist environmental conditions (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure: |
| 1. | Spray the suspected area with a five percent saltwater solution. |
Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution.
| 2. | Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at least 30 seconds. |
| 3. | If the DTC returns, replace the suspected harness. |
| • | If an intermittent malfunction exists refer to Intermittents and Poor Connections Diagnosis in Wiring Systems for further diagnosis. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | ||
2 | Inspect the WSS for physical damage. Is physical damage of the WSS evident? | -- | ||
3 | Replace the WSS. Refer to Wheel Speed Sensor Replacement . Is the replacement complete? | -- | -- | |
Is the resistance within the range specified in the value(s) column? | 800-1700 ohms | |||
Is the AC voltage within the range specified in the value(s) column? | Above 30 mV | |||
6 | Using J 39200 DMM, measure the resistance between the WSS terminal 1 and ground. Is the resistance within the range specified in the value(s) column? | OL (infinite) | ||
7 |
Is the resistance within the range specified in the values column? | OL (infinite) | ||
8 | Repair short between CKT(s) PU251 and XU251. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
9 | Using J 39200 DMM, measure the resistance between terminals 5 and 19 of J 39700 . Is the resistance within the range specified in the values column? | OL (infinite) | ||
10 | Repair CKT PU251 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
11 | Using J 39200 DMM, measure the resistance between terminals 4 and 19 of J 39700 . Is the resistance within the range specified in the values column? | OL (infinite) | ||
12 | Repair CKT XU251 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
13 | Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the replacement complete? | -- | -- | |
14 |
Does the DTC reset as a current DTC? | -- |
