P1522
DTC P1522: Brake Booster Pressure Sensor Circuit Low Input1. Reset the ECM.
2. Start the engine. Hold the engine speed at 3,000 rpm with the transmission in Park or neutral until the radiator fan comes on, then let it idle.
Is DTC P1522 or P1523 indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the brake booster pressure sensor and at the ECM.
3. Turn the ignition switch OFF.
4. Turn the ignition switch ON (II).
5. Measure voltage between ECM connector terminals C18 and C28.
Is there about 5 V?
YES - Go to step 6.
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
6. Measure voltage between ECM connector terminals C18 and A10.
Is there about 1 - 3 V?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO - Go to step 7.
7. Measure voltage between ECM connector terminals C18 and A10.
Is there about 5 V?
YES - Go to step 16.
NO - Go to step 8.
8. Turn the ignition switch OFF.
9. Disconnect the 3P connector from the brake booster pressure sensor.
10. Turn the ignition switch ON (II).
11. Measure voltage between ECM connector terminals C18 and A10.
Is there about 5 V?
YES - Replace the brake booster pressure sensor.
NO - Go to step 12.
12. Measure voltage between the brake booster pressure sensor 3P connector terminal No.1 and body ground.
Is there about 5 V?
YES - Go to step 13.
NO - Repair open in the wire between the ECM (C28) and the brake booster pressure sensor.
13. Turn the ignition switch OFF.
14. Disconnect ECM connector A (32P) from the ECM.
15. Check for continuity between ECM connector terminal A10 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (A10) and the brake booster pressure sensor.
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
16. Turn the ignition switch OFF.
17. Disconnect the 3P connector from the brake booster pressure sensor.
18. Turn the ignition switch ON (II).
19. Measure voltage between the brake booster pressure sensor 3P connector terminals No.1 and No.2.
Is there about 5 V?
YES - Go to step 20.
NO - Repair open in the wire between the ECM (C18) and the brake booster pressure sensor.
20. Measure voltage between the brake booster pressure sensor 3P connector terminals No.2 and No.3.
Is there about 5 V?
YES - Replace the brake booster pressure sensor.
NO - Repair open in the wire between the ECM (A10) and the brake booster pressure sensor.