DTC U3000-49 (SRS Unit)

DTC U3000-49  : Internal Failure of the SRS Unit

NOTE: 

• Before doing this troubleshooting procedure, find out if the vehicle was in a collision. If so, verify that all the required components were replaced with new components of the correct part number and were properly installed .
• Before doing this troubleshooting procedure, review SRS Precautions and Procedures , General Troubleshooting Information , and 12 Volt Battery Terminal Disconnection and Reconnection .

DTC (SRS)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   -2. Turn the vehicle to the ON mode, then wait for 10 seconds.

   -3. Check for DTCs with the HDS.

   DTC Description	DTC
   U3000-49 Internal failure of the SRS unit

   Is DTC U3000-49 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Go to Troubleshooting Intermittent Failures. If another DTC is indicated, troubleshoot the DTC.

2. Shorted wire check (SWS+/PWR SWS line to power)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

   -3. Disconnect the following connectors.

   SRS unit connector B (39P)

   Front passenger's weight sensor (front inner side) 3P connector (on the front passenger's seat wire harness)

   Front passenger's weight sensor (rear inner side) 3P connector (on the front passenger's seat wire harness)

   -4. Reconnect the negative cable to the 12 volt battery.

   -5. Turn the vehicle to the ON mode.

   -6. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	SRS unit connector B (39P): disconnected
   	Front passenger's weight sensor (front inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   	Front passenger's weight sensor (rear inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   Test point 1	SRS unit connector B (39P) No. 26
   Test point 2	Body ground

   Is there 0.2 V or less?

   YES 

   The SWS+/PWR SWS wire is not shorted to power. Go to step 3.

   NO 

   Short to power in the floor wire harness or the front passenger's seat wire harness; replace the faulty harness, then clear the DTC.

3. Shorted wire check (SWS+/PWR SWS line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the negative cable from the 12 volt battery, then wait at least 3 minutes.

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	SRS unit connector B (39P): disconnected
   	Front passenger's weight sensor (front inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   	Front passenger's weight sensor (rear inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   Test point 1	SRS unit connector B (39P) No. 26
   Test point 2	Body ground

   Is there an open circuit, or at least 1 MΩ?

   YES 

   The SWS+/PWR SWS wire is not shorted. Go to step 4.

   NO 

   Short to ground in the floor wire harness or the front passenger's seat wire harness; replace the faulty harness, then clear the DTC.

4. Shorted wire check (SWS+/PWR SWS line to SWS-/GND SWS line)

   -1. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	SRS unit connector B (39P): disconnected
   	Front passenger's weight sensor (front inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   	Front passenger's weight sensor (rear inner side) 3P connector (on the front passenger's seat wire harness): disconnected
   Test point 1	SRS unit connector B (39P) No. 26
   Test point 2	SRS unit connector B (39P) No. 28

   Is there an open circuit, or at least 1 MΩ?

   YES 

   The SWS+/PWR SWS to SWS-/GND SWS wires are OK. Go to step 5.

   NO 

   Short to another wire in the floor wire harness or the front passenger's seat wire harness; replace the faulty harness, then clear the DTC.

5. Front passenger's weight sensor check

   -1. Substitute a known-good front passenger's weight sensors as an assembly .

   -2. Reconnect the following connectors.

   SRS unit connector B (39P)

   Front passenger's weight sensor (front inner side) 3P connector (on the front passenger's seat wire harness)

   Front passenger's weight sensor (rear inner side) 3P connector (on the front passenger's seat wire harness)

   -3. Reconnect the negative cable to the 12 volt battery.

   -4. Clear the DTCs with the HDS.

   -5. Turn the vehicle to the ON mode, then wait for 10 seconds.

   -6. Check for DTCs with the HDS.

   DTC Description	DTC
   U3000-49 Internal failure of the SRS unit

   Is DTC U3000-49 indicated?

   YES 

   The front passenger's weight sensor is OK. Faulty SRS unit or poor connection at SRS unit connector B (39P) and the SRS unit. Check the connection; if the connection is OK, check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the SRS unit . If the DTC does not clear, replace the floor wire harness or the front passenger's seat wire harness.

   NO 

   Faulty front passenger's weight sensor. Replace the front passenger's weight sensors as an assembly .