Circuit Description
The RPM signal circuit provides the electronic brake control module (EBCM) with an indication of engine RPM to help determine traction control system (TCS) control methods and rates when a TCS event takes place.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0236 TCS RPM Signal Circuit Malfunction
Conditions for Running the DTC
| • | The ignition switch is ON and the engine running. |
| • | After 2 seconds starting, and if there is a undervoltage condition |
Conditions for Setting the DTC
The EBCM does not received an RPM input signal after one second, after the engine has been started.
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | A malfunction DTC is stored. |
| • | The TRAC OFF indicator is turned on. |
| • | The TCS is disabled. The ABS remains functional. |
Conditions for Clearing the DTC
| • | The condition for DTC is no longer present and the scan tool Clear DTCs function is used. |
| • | 100 ignition cycles have passed with no DTCs detected. |
Diagnostic Aids
Perform a thorough inspection of the wiring. Perform a thorough inspection of the connectors. Failure to carefully and fully inspect the wiring and the connectors may result in misdiagnosis. Misdiagnosis causes part replacement with reappearance of the malfunction.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
If the instrument panel tachometer is working properly, the cause of the malfunction is most likely between the powertrain control module (PCM) and the EBCM, or the EBCM itself.
-
At this point, the PCM is likely causing the malfunction. Refer to the OBD system check.
Step | Action | Value(s) | Yes | No | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views or Engine Controls Connector End Views | ||||||||||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||||||||
Does the I/P tachometer work properly as the engine RPM changes? | -- | Go to Step 3 | Go to Step 9 | |||||||||||||||||||
3 |
Is the resistance within the specified range? | 0-5 ohms | Go to Step 4 | Go to Step 10 | ||||||||||||||||||
4 | Use a J 39200 DMM to measure the resistance between the universal breakout box terminal 11 and a good ground. Is the resistance within the specified range? | 0L | Go to Step 5 | Go to Step 11 | ||||||||||||||||||
5 |
Is the voltage within the specified range? | 0-2 V | Go to Step 6 | Go to Step 12 | ||||||||||||||||||
6 |
Are the following signs present on either connector:
| -- | Go to Step 13 | Go to Step 7 | ||||||||||||||||||
7 |
Did DTC C0236 reset? | -- | Go to Step 8 | |||||||||||||||||||
8 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Is the repair complete? | -- | Go to Step 14 | -- | ||||||||||||||||||
Check the PCM. Refer to Diagnostic System Check - Vehicle . Is the repair complete? | -- | Go to Step 14 | -- | |||||||||||||||||||
10 | Repair an open between PCM and EBCM tach signal circuit. Refer to Wiring Repairs . Is the repair complete? | -- | Go to Step 14 | -- | ||||||||||||||||||
11 | Repair a short to ground in tach signal circuit. Refer to Wiring Repairs . Is the repair complete? | -- | Go to Step 14 | -- | ||||||||||||||||||
12 | Repair a short to voltage in TACH signal circuit. Refer to Wiring Repairs . Is the repair complete? | -- | Go to Step 14 | -- | ||||||||||||||||||
13 | Replace all terminals or replace connectors that exhibit signs of the following:
Refer to Wiring Repairs . Is the repair complete? | -- | Go to Step 14 | -- | ||||||||||||||||||
14 |
Dose the DTC reset? | -- | Go to Step 2 | System OK | ||||||||||||||||||
