Circuit Description
The pump motor is an integral part of the BPMV, while the pump motor relay is integral to the EBCM. The pump motor relay is not engaged during normal system operation. When ABS or TCS operation is required the EBCM activates the pump motor relay and battery power is provided to the pump motor.
Conditions for Setting the DTC
| • | Pump motor voltage is not present 60 milliseconds after activation of the pump motor relay. |
| • | Pump motor voltage is present for more than 2.5 seconds with no activation of the pump motor relay. |
| • | Pump motor voltage is not present for 40 milliseconds after the pump motor relay is commanded off. |
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | The ABS/TCS disables. |
| • | The amber ABS/TCS indicator(s) turn on. |
| • | The Red BRAKE Warning indicator turns 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 DTCs detected. |
| Important: After the DTC is cleared using ignition cycle default, the vehicle must be driven above 12 Km/h (8 mph) for the ABS/TCS indicator(s) to turn off. |
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 an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The numbers below refer to step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | ||
2 | Inspect the 40A ABS BATT 1 Maxifuse® , in the Underhood Electrical Center 1. Is the fuse OK? | -- | ||
3 |
Is the fuse OK? | -- | ||
Is the resistance within the range specified in the value(s) column? | OL (infinite) | |||
5 |
Is the fuse OK? | -- | ||
6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Is the replacement complete? | -- | -- | |
7 |
Is the resistance within the range specified in the value(s) column? | 0-5 ohms | ||
8 | Repair CKT 150 for an open or high resistance. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
9 |
Is the voltage within the range specified in the value(s) column? | B+ | Go to Power Distribution Schematics in Electrical Diagnosis | |
Using J 39200 DMM, measure the voltage at terminal 13 of J 39700 . Is the voltage within the range specified in the value(s) column? | B+ | |||
11 | Replace EBCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | -- | |
12 | Repair short to ground in CKT 302. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
13 | Repair open in CKT 302. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
14 |
Is the fuse OK? | -- | ||
15 |
Is the resistance within the range specified in the value(s) column? | 0-4 ohms | ||
16 |
Does the DTC reset as a current DTC? | -- |
