The Electronic Brake Control Module (EBCM) receives a voltage signal from the left rear wheel speed sensor through terminals 8 and 14. As a toothed reluctor wheel ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce a small AC voltage signal. This signal's frequency is proportional to the wheel speed.
• | DTC C0045 will set when the EBCM detects an open, a short to voltage, or a short to ground in CKT 884 or CKT 885. |
• | DTC C0045 can be set anytime. |
• | A malfunction DTC stores. |
• | The ABS disables. |
• | The ABS warning indicator turns ON. |
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
Inspect for the following when diagnosing this part of the Antilock Brake System (ABS):
• | Faulty electrical circuits between the left rear wheel speed sensor and the EBCM. These faults include the following: |
- | Open and or high resistance |
- | Short to voltage |
- | Short to ground |
• | Faulty left rear wheel speed sensor (out of range resistance). |
An intermittent malfunction is most likely caused by a poor connection, rubbed thorough wire insulation, or by a wire that is broken inside the insulation.
If the ABS indicator lamp is ON only during humid conditions (rain, snow, vehicle wash), thoroughly inspect the left rear wheel speed sensor circuitry for signs of water intrusion.
Thoroughly inspect any 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 |
The number(s) below refer to the step number(s) on the diagnostic table.
The Diagnostic System Check must be the starting point for any ABS related diagnosis.
Tests for wheel speed sensor internal resistance for proper values.
Tests for wheel speed sensor circuits shorted together.
Tests for a short to ground in CKT 885.
Tests for a short to ground in CKT 884.
Tests for a short to voltage in CKT 885.
Tests for a short to voltage in CKT 884.
Tests for an open or high resistance in CKT 885.
Tests for an open or high resistance in CKT 884.
Tests for a poor connections at electrical connectors.
Determines whether the condition is intermittent and not due to a faulty EBCM.
Important: Wheel speed sensor resistance increases with an increase in sensor temperature.
When measuring for a short to ground in a wheel speed sensor wiring circuit manually switch to J 39200 (Digital Multimeter) to the Meg-Ohms range. This will ensure a high resistance short to ground can be found. See J 39200 owners manual.Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |||||||
2 |
Is the resistance within the range specified in the Value(s) column? | 840-2030 ohms | ||||||||
3 |
Is the resistance equal to the value specified in the Value(s) column? | OL (Infinite) | ||||||||
4 | Use J 39200 DMM in order to measure the resistance between the left rear wheel speed sensor connector terminal A (harness side) and ground. Is the resistance equal to the value specified in the Value(s) column? | OL (Infinite) | ||||||||
5 | Use J 39200 DMM in order to measure the resistance between the left rear wheel speed sensor connector terminal B (harness side) and ground. Is the resistance equal to the value specified in the Value(s) column? | OL (Infinite) | ||||||||
6 |
Is the voltage within the range specified in the Value(s) column? | 0-1 V | ||||||||
7 | Use J 39200 DMM in order to measure the voltage between the left rear wheel speed sensor connector terminal B (harness side) and ground. Is the voltage within the range specified in the Value(s) column? | 0-1 V | ||||||||
8 | Use J 39200 DMM in order to measure the resistance between the left rear wheel speed sensor connector terminal A (harness side) and the EBCM electrical connector terminal 8 (harness side). Is the resistance within the range specified in the Value(s) column? | 0-2 ohms | ||||||||
9 | Use J 39200 DMM in order to measure the resistance between the left rear wheel speed sensor connector terminal B (harness side) and the EBCM electrical connector terminal 14 (harness side). Is the resistance within the range specified in the Value(s) column? | 0-2 ohms | ||||||||
10 |
Is the action complete? | -- | -- | |||||||
11 |
Is DTC C0045 set as a Current DTC? | -- | ||||||||
12 | Replace the left rear wheel speed sensor. Refer to On-Vehicle Service for Wheel Speed Sensor Replacement procedures. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
13 | Repair the short between CKT 884 and CKT 885. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
14 | Repair short to ground in CKT 885. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
15 | Repair short to ground in CKT 884. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
16 | Repair short to voltage in CKT 885. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
17 | Repair short to voltage in CKT 884. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
18 | Repair an open or high resistance in CKT 885. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
19 | Repair an open or high resistance in CKT 884. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | -- | ||||||
20 | A malfunction is not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC. Is action complete? | -- | Go to Diagnostic System Check | -- | ||||||
21 |
Is the repair complete? | -- | Go to Diagnostic System Check | -- |