Fault (Trouble) Code 36522

There are three different conditions associated with fault code 36522 and the safety circuit. For complete test procedure of this circuit, follow the fault tracing procedure for all three conditions.

Short To +12V

1. With ignition in Drive position, enter ISAT command code 201. If display shows 8B100, it indicates continuity from pin 8 to pin 51. If display shows 8B000, it indicates an open circuit.
2. With ignition in Off position, remove ECU and connect breakout box. With ignition in Drive position, ensure voltage exists across pin 8 and ground and across pin 51 and ground.
a. If voltage exists, check circuit between pins 8 and 51 for short to +12V.
b. If voltage does not exist, turn ignition to Off position, fit and connect ECU, then clear fault code and see if it is regenerated.
3. If fault code 36522 is regenerated, continue with ``Short To Ground'' test procedure. If no other faults are found after test procedure is completed, replace ECU.

Short To Ground

1. With ignition in Drive position, enter ISAT command code 201. If display shows 8B100, it indicates continuity from pin 8 to pin 51. If display shows 8B000, it indicates an open circuit.
2. Turn ignition to Off position, remove ECU and connect breakout box.
3. Measure resistance across pin 8 and ground and across pin 51 and ground. Resistance should be infinity.
4. If resistance is not infinity, check leads and connections for short to ground.

Open Circuit

1. With ignition in On position, ensure pump is running and check brake fluid level.
a. If brake fluid level is low, check system for leaks. Add brake fluid if necessary to bring to correct level.
b. If pump is not running or pressure is below 1522 psi, check fuse for pump (ABS 30A) and pump relay operating circuit (ABS 10A).
c. If fluid level, pump and pressure are satisfactory, go to step 2 and check safety circuit.
2. With ignition in Drive position, enter ISAT command code 201. If display shows 8B100, it indicates circuit continuity. If display shows 8B000, it indicates an open circuit. With ignition in Off position, connect breakout box. Measure resistance across pins 8 and 51 to determine whether circuit has continuity or is open.
3. If circuit is open, check circuit continuity as follows:
a. Between ECU pin 8 and pin 1 on reservoir switch.
b. Between pins 1 and 2 on reservoir switch.
c. Between pin 2 at reservoir and pin 3 on pressure-warning switch.
d. Between pins 3 and 5 on pressure-warning switch.
e. Between pin 5 on pressure-warning switch and ECU pin 51.
4. Discharge accumulator, then with ignition in On position, check for battery voltage at pin 14 (pump relay operation).
a. If voltage does not exist, go to step 6.
b. If voltage exists, switch ignition to Off position, check motor winding by measuring resistance across pin 14 and ground.
c. Resistance should be approximately 10 ohms. If not, check resistance across pins 1 and 2 on motor.
d. If resistance is as specified, check YE lead between pin 1 on motor and pin 87 on pump relay, then BK lead between pin 2 on motor and grounding point G2.
e. Check diode circuit between pin 87 on pump relay and ground by removing relay and disconnecting pump connector before measuring resistance.
f. Ensure diode has continuity in one direction and no continuity in the other direction.
5. If the fault has not been found at this point of diagnosis, replace pump.
6. With ignition in On position and pump not running, ensure battery voltage is reaching ECU pin 50. If not, check that voltage is reaching pins 85 and 86 on pump relay and the 10-A fuse. Ensure circuit continuity in leads from pin 86 on pump relay via fuse holder to pin +54 on ignition switch.
7. If voltage exists at pin 86 but not at pin 85, replace pump relay.
8. If battery voltage exists at pin 50, exciter circuit is satisfactory but is not being grounded by pressure-warning switch.
a. With ignition in Off position, accumulator discharged and ECU connector disconnected, ensure pressure-warning switch is closed by measuring circuit continuity between pin 50 and ground.
b. If a fault is found in circuit, check BU lead between pump relay pin 85 and pin 4 on pressure-warning switch, between pins 4 and 1 on switch, then check BK lead between pin 1 on switch and ground.
9. If continuity does not exist between pins 1 and 4 on pressure-warning switch connector, replace switch.