P1522
DTC P1522: Brake Booster Pressure Sensor Circuit Low Voltage1. Reset the ECM with the HDS.
2. Start the engine, and let it idle.
3. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1522 indicated?
YES - Go to step 4.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the brake booster pressure sensor and the ECM.
4. Turn the ignition switch OFF.
5. Disconnect the brake booster pressure sensor 3P connector.
6. Turn the ignition switch ON (II).
7. Measure voltage between brake booster pressure sensor 3P connector terminals No.1 and No.2.
Is there about 5 V?
YES - Go to step 9.
NO - Go to step 8.
8. Measure voltage between ECM connector terminals C18 and C28.
Is there about 5 V?
YES - Repair open in the wire between the ECM (C28) 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.
9. Turn the ignition switch OFF.
10. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after the radiator fan stops.
11. Disconnect ECM connector A (32P).
12. Check for continuity between brake booster pressure sensor 3P connector terminal No.3 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (A10) and the brake booster pressure sensor.
NO - Go to step 13.
13. Substitute a known-good brake booster pressure sensor, then recheck.
14. Check for Temporary DTCs or DTCs with the HDS.
Is DTCP1522 indicated?
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 - Check the brake vacuum line. If the line is OK, replace the original brake booster pressure sensor.