DTC 51

Fig. 143 Code 51: Right Rear ABS Valve Solenoid Fault (Part 1 Of 2).:

Code 51: Right Rear ABS Valve Solenoid Fault (Part 2 Of 2).:

DTC 51: Right Rear ABS Valve Solenoid Fault:

CIRCUIT DESCRIPTION
The right rear valve solenoid in the BPM Valve may be commanded to three different positions by the EBTCM/EBCM. Valve position is determined by the amount of current which is allowed to flow through the valve solenoid coil.

The valve solenoid circuits receive power through the valve relay on the BPM Valve. The valve relay is engaged at KEY-ON and remains engaged throughout the ignition cycle. Valve solenoid circuits should have battery voltage available at all times.

When the key is turned to RUN, power is supplied to the EBTCM/EBCM. The EBTCM/EBCM will complete an internal self-check before providing ground to the valve relay. When the valve relay is energized, battery power is supplied to the valve solenoids.

TEST CONDITION(S)
1. Tested continuously.

FAILURE CONDITION(S)
While standing or driving:
1. Valve solenoid cannot be activated.
OR
2. Valve solenoid is activated in a defective way.

ACTION TAKEN
1. Code set.
2. ABS/TCS switched "OFF."
3. "ANTILOCK" indicator "ON."
4. "TRACTION DISABLED" message displayed. (vehicles with TCS)

Code 51 will set when the expected position of the right rear valve solenoid does not match the commanded position from the EBTCM/EBCM. Conditions which could cause Code 51 to set are: damage to the right rear valve solenoid; and open circuit; or a short circuit to ground or battery on CKT 859.

TEST DESCRIPTION
Test numbers refer to circled numbers on the diagnostic chart.
1. Damage to CKT 886 may result in multiple valve solenoid codes setting.
2. Checks CKT 886 for opens or high resistance from EBTCM/EBCM terminal "23" to "32".
3. Determines which branch of CKT 886 has an open or high resistance.
4. Checks the integrity of CKTs 859 and 886, the RR ABS Valve Solenoid circuitry internal to the BPM Valve, and the RR ABS Valve Solenoid coil.
5. Determines whether a problem found in Step 4 is due to an open in CKT 859, 886, or a faulty BPM Valve.
6. Determines whether the problem found in Step 4 is due to an open in CKT 859 or 886.
7. Checks for a short to battery in CKT 886 using EBTCM/EBCM terminal "20" as ground.
8. Checks for a short to battery in CKT 859, using EBTCM/EBCM terminal "20" as ground.
9. Checks for a short to ground in CKT 886 using EBTCM/EBCM terminal "20" as ground.
10. Checks for a short to ground in CKT 859, using EBTCM/EBCM terminal "20" as ground.
11. Checks wiring and connectors for intermittents.
12. Uses the TECH 1 to exercise the RR ABS valve solenoid and check it for proper operation.
13. Determines whether the code was set by an intermittent conditions or an EBTCM/EBCM fault.

DIAGNOSTIC AIDS
All tests using J 39700 Universal Breakout Box terminal "20" are using the terminal as ground. These tests, of course, assume that the ground CKT 1250 terminal "20" is good.