Procedure

The basics for diagnosing a Supplemental Restraint System:

1. Clearly identify the customer description of the condition to be serviced, when it happens, under what conditions, over what type of road surface.

2. Using the Hi-Scan Pro, read the codes from the system. Check carefully to see if the code is an active or history code. History codes may be more difficult to diagnose, since the condition that set the code may no longer be present. This will make the customer's description very important in determining why the vehicle was brought in for repair.

^ Active Code - Indicates the condition that set the code is still present.

^ History Code - Indicates that the condition that set the code is intermittent or no longer present. (In some cases, if the condition has not repeated, the code may clear after 5 key cycles.) An "H" displayed to the right of the code description identifies the code as a history code. On some models, such as the XG300, there is a menu for "Historic Codes" which has additional information.

3. Identify that part of the system to which the code and the customer description apply. At this time you may have enough information to determine the service procedure, but usually some diagnosis will be required.

CAUTION:
Before proceeding with the diagnosis, the negative battery cable must be removed from the terminal for a minimum of 30 seconds.





4. Access the SRSCM connector. Refer to the appropriate shop manual or electrical trouble shooting manual for the exact location. Determine which pins in the connector are used for the circuit to be diagnosed. If the circuit contains an air bag or seat belt pretensioner, unplug it and plug in the dummy load.

5. Dummy loads are used to test the wiring in each air bag or pretensioner circuit. The dummy load is used to simulate the electrical "load" or resistance of the air bag or pretensioner. This allows the circuit resistance to be measured safely, without accidentally deploying the air bag/ pretensioner.





^ Use the appropriate adapter and the dummy load. Unplug the air bag/ pretensioner and plug the dummy load into the air bag wire harness. Adapters are shown.

^ Connect the adapter to the dummy load 2.0 Ohm connector for air bag circuits.

^ Connect the adapter to the dummy load 2.2 Ohm connector for pretensioner circuits.





6. Attach a good quality DVOM to the red and black leads on the diagnosis checker (SST # 0957A-38000). Use the pins on the diagnosis checker to probe the pins in the SRSCM wire harness connector. Based on how the circuit operates, you may be looking for resistance or voltage. If a shorting bar in the connector affects the circuit, use the plastic wire tie end on the SST to open the shorting bar. If measuring through a dummy load, you should measure the dummy load resistance plus 0.0 to 0.2 Ohms for wire and connector resistance, and 0.2 Ohms for the clock spring resistance.

A NOTE ON USING THE DIAGNOSIS CHECKER (SST # 0957A-38000):








The checker is designed to work with the sharp probes found on most common multimeters. Just push the probe into the female pins in the white plastic connector on the SST. Some multimeters have large handles on the probes, like the Fluke brand. In this case, use a pin removal tool to pop the black wire terminal from the white connector, leaving just the red wire in place. This will allow the multimeter to connect to the SST.








SRS DIAGNOSTIC TROUBLE CODE INDEX

HOW TO DIAGNOSE THE SYSTEM (BASED ON THE DIAGNOSTIC CODE

CIRCUIT RESISTANCE HIGH, LOW, OR OPEN (CODES B1345, B1346, B1347, B1351, B1352, B1353, B1360, B1361, B1362, B1366, B1367, B1368, B1377, B1378, B1379, B1382, B1383, B1386)

These codes may indicate an open connector, but may also include detection of a deployed air bag or seat belt pretensioner, a connector with unusually high resistance, or an open/short circuit in the wiring.

Active Codes:

^ Check all of the connections (including the clock spring on the DAB circuit),

^ Connect the dummy load, and access the SRSCM wire harness connector.

^ Check for 2 ohms (2.2 ohms on the SBPT circuits) across the terminals in the SRSCM connector. (If there are less than 0.3 ohms, check to be sure that you opened the shorting bar. Refer to step 6 of this TSB for instructions).

^ Locate the source of the high resistance.

If the circuit tests OK, reconnect the SRSCM, leave the dummy load on the circuit, and reconnect the power to the system. Clear the existing code, then remove the Hi Scan Pro, and cycle the key off, then on. If the code does not reset, switch the dummy load with the air bag/SBPT it replaced (disconnect the battery while making the switch). If the same code returns, the air bag/SBPT is the cause of the code. If the code does not return with either the dummy load or the air bag/SBPT, there is an intermittent condition.

Historical codes:

^ Check for a partially connected connector; a connector pulled very tight, or a connector that may be pulled while the vehicle is driven.

SEAT BELT SWITCH OPEN/SHORT TO BATTERY/SHORT TO GROUND (CODES B1511, B1512, B1513, B1514)

These codes may indicate an open circuit, or a short to power/ground. Test from the SRSCM connector using the same procedure as the circuit resistance codes above, but no dummy load is required.

^ Resistance between the two wires in each circuit should range between 1000 ohms and 4000 ohms (seat belt unlatched and latched).

^ Resistance to ground should be infinite. If there is a reading to ground, reconnect the battery and measure the circuit voltage (the SRSCM is still unplugged). Zero volts means the circuit is shorted to ground.
12V means the circuit is shorted to a power circuit.

For Historical Codes check for an intermittent short or a loose connector.

CIRCUIT SHORT TO BATTERY OR SHORT TO GROUND (CODES B1348, B1349, B1354, B1355, B1363, B1364, B1369, B1370, B1380, B1381, B1384, B1385, B1401, B1402, B1404, B1405)

These codes may result from to a short to ground or 12 Volts in the circuit. The satellite sensor circuits will indicate code B1405 if they are unplugged, or if the connector is pulled too tightly.

Active Codes:

^ The protective yellow wire covering may make it easier to see how the short occurred if it results from wiring damage.

^ Trace the system wiring to see the damage.

^ With the power off, the dummy load connected, and the SRSCM unplugged, you may be able to use a "Short Finder" to locate the short if it cannot be found visually.

Historical Codes:

^ Check for an exposed wire,

^ Check for damage to the wire loom

^ Check for a connector pulled very tight. The damage has to make intermittent contact with ground or a 12 Volt circuit.

PPD SHORT TO BATTERY, SHORT TO GROUND, OPEN CIRCUIT, SHORT CIRCUIT (PPD RESISTANCE READ DIRECTLY BY SRSCM) (CODES B1461, B1462, B1463, B1464)

These codes may indicate an open circuit, or a short to power/ground. Test from the SRSCM connector (no dummy load is required).

^ Use an Ohm meter to test the resistance of the PPD sensor from the SRSCM connector. The resistance should vary from very high resistance with no weight on the passenger seat to lower resistance with weight (greater than 50k Ohms with no weight to less than 50k Ohms with 33 lbs). There is a diode inside the PPD sensor, which will affect the values measured, but the overall measurements will be similar. If there is a reading with the DVOM connected one way but not when connected the other way, the PPD sensor has an open circuit.

^ Resistance to ground should be infinite. If there is a reading to ground, reconnect the battery and measure the circuit voltage (the SRSCM is still unplugged). Zero volts means the circuit is shorted to ground. 12V means the circuit is shorted to a power circuit.

For Historical Codes look for an intermittent short or a loose connector.

SATELLITE LEFT/RIGHT OPERATION, PPD OPERATION, SATELLITE COMMUNICATION ERROR, PPD COMMUNICATION ERROR (CODES B1400, B1403, B1406, B1407, B1408, B1409, B1410).

These codes indicate an error with the signal coming from the sensor to the SRSCM. The PPD circuit has power and ground wires as well as the signal wire. The Satellite sensors have a pair of signal wires per sensor.

NOTE:
Code B1409 indicates a different side (Left/Right) on different models, but the diagnostic steps are the same.

Active Codes:

^ Check each connection in the suspect circuit.

^ Use a DVOM to measure the continuity of each wire from the sensor to the SRSCM connector.

Historical Codes:

^ Check for a partially connected connector

^ Check for a connector pulled very tight. For codes B1406 or B1407:

^ Use a test light to verify the power and ground wires to the PPD interface. With the SRSCM connector unplugged, reconnect the battery and turn on the ignition key. At the PPD connector, connect the test light between the ground wire and the power wire (pin 4 to pin 1). The test light should illuminate brightly.

^ Use an Ohm meter to test the resistance of the PPD sensor. With the sensor connector unplugged from the interface, measure the resistance between the two leads as pressure is applied to the center of the seat cushion. The resistance should vary from very high resistance with no weight to lower resistance with weight (greater than 50k Ohms with no weight to less than 50k Ohms with 33 lbs). There is a diode inside the PPD sensor, which will affect the values measured, but the overall measurements will be similar. If you get a reading with the DVOM connected one way but not when connected the other way, the PPD sensor has an open circuit.

^ If these tests are OK, and the code is an active code, replace the PPD interface. If the code was historical, check for a partially connected connector or a connector pulled very tight.

BATTERY VOLTAGE TOO HIGH OR LOW (CODES B1111, B1112)

These codes indicate that the battery voltage was too high or too low while the system was operational. This code will not set a historical code, the light will turn off after the input voltage returns to the 10 to 16.5 volt range. It is important to note that the ground wire is an integral component in the system. This battery voltage may measure low at the module if the ground wire is not fully connected to ground.

1. Test the voltage across the battery, verify that the battery voltage is about 13 to 15 volts when the engine is idling.

^ If it is not, diagnose the battery and the charging system, as per the shop manual.

2. Access the SRSCM connector (disconnect the battery and wait 30 seconds before removing the connector).





3. Test the voltage between the power supply pin and the ground pin of the SRSCM connector with a voltmeter and a test light (to load the circuit). It should be within the 10 to 16.5 volt range while the test light is illuminated.

CAUTION:
Do not probe the SRSCM connector directly. Use the diagnosis checker harness (SST # 0957A38000) as shown.

^ If it is not within the 10 to 16.5 volt range, test the voltage between the power supply pin of the SRSCM connector to a good ground. If that voltage is correct, but the voltage between the power supply pin and the ground pin of the SRSCM connector was not, then diagnose the ground wire.

If the voltages at the connector check out OK, then reconnect the SRSCM (disconnect the battery and wait 30 seconds before connecting the connector), and start the car. If the same code is repeated, then replace the SRSCM.

CONTROL MODULE INTERNAL FAULT, SATELLITE SENSOR WRONG ID, ECU MISMATCHING (CODES B1414, B1415, B1620, B1661)

The SRSCM must be replaced.

CRASH RECORDED, CRASH RECORDED LH/RH SIDE AIR BAG (CODES B1650, B1651, B1652, B1660, B1663)

These codes indicate that the SRSCM deployed the air bags indicated. These codes cannot be reset, as the module can only deploy an airbag one time. The module will need to be replaced. The seat belts worn during the collision, the wire harness, and the deployed air bags must also be replaced. (refer to TSB# 00-90-004)

SEAT BELT PRETENSIONER DEPLOYMENT (CODES B1662, B1664)

These codes indicate that a seat belt pretensioner was deployed. These codes will be accompanied by codes B1361 or B1367. Replace the appropriate seat belt and buckle, then clear the codes. This repair is not covered by the vehicle warranty.

BELT PRETENSIONER DEPLOYED 6 TIMES (CODE B1658)

The seat belt pretensioners have deployed 6 times, the maximum allowable for one SRSCM. Replace the SRSCM at the same time as the seat belt pretensioner(s). This repair is not covered by the vehicle warranty

WARNING LAMP OPEN, SHORT TO GROUND, SHORT TO BATTERY (CODES B2500, B2503, B2504)

The SRSCM has detected a warning lamp circuit condition requiring diagnosis. It detects the voltage from the warning lamp circuit. There should be 12V when the warning lamp is off, and OV when the warning lamp is on. This code can also be set if the vehicle battery is discharged sufficiently so that the engine cannot start, and then it is subsequently jump started. This requires asking the customer about the events leading to the warning lamp illumination.

1. Check that the fuse or the warning lamp circuit has power. It uses a different fuse than the SRSCM. Refer to the shop manual or electrical trouble shooting manual for the correct fuse. Verify that it has power.

2. Evaluate the warning lamp circuit at the SRSCM connector.

^ Access the SRSCM connector (disconnect the battery and wait 30 seconds. Remove the connector from the SRSCM.

^ Reconnect the power.

^ Use the diagnosis checker SST to test for power on the warning lamp input.

^ Use the wire tie end on the SST to open the shorting bar between pin 7 (warning lamp input) and pin 6 (ground). Then measure the voltage (with a DVOM and the Diagnosis Checker) across pins 6 & 7. There should be 12 volts. If not, verify that pin 6 has good continuity to ground, verify the warning lamp is good, and look for an open connector or open circuit in the wire between the fuse and the lamp, and between the lamp and the SRSCM.

^ Verify that you can turn the warning lamp on and off by removing the wire tie from the shorting bar (on when shorted), and re-inserting it into the shorting bar (off when shorting bar is opened). If the warning lamp stays on, then look for a short to ground between the SRSCM and the warning lamp. You may need to remove the bulb from the instrument cluster depending on the type of short finding equipment used. A visual inspection of the harness will probably reveal the short location.

3. If the tests show the proper inputs, then reconnect the SRSCM (disconnect the battery and wait 30 seconds before reconnecting the connector), clear the code, disconnect the HDS Scanner/Hi Scan, cycle the key off for 30 seconds, turn the key on, and check to see if the code is reset. If it is, then replace the SRSCM.

ELECTRICAL TROUBLESHOOTING MANUAL SCHEMATICS




















The five illustrations contain schematics for the Air Bag System in each of the 2000 models: Accent, Elantra, Santa Fe, Sonata and Tiburon. These schematics are copies of those found in the shop manuals or ETMs and the page numbers are shown on each illustration.