U0170-LOST COMMUNICATION W/UP-FRONT LEFT SATELLITE ACCELERATION SENSOR
For a complete wiring diagram Refer to Section 8W.
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When Monitored:
The Occupant Restraint Controller (ORC) continuously communicates with the Front Left Impact Sensor over the sensor signal circuit. The sensor communication and on board diagnostics are powered by
the ORC signal.
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Set Condition:
This code will set, if the ORC and the Front Left Impact Sensor do not establish and maintain valid data communications.
Possible Causes
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(R79) SIGNAL CIRCUIT SHORTED TO BATTERY
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(R79) SIGNAL CIRCUIT SHORTED TO GROUND
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(R79, R81) FRONT LEFT IMPACT SENSOR CIRCUITS SHORTED TOGETHER
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(R81) FRONT LEFT IMPACT SENSOR GROUND CIRCUIT OPEN
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(R79) FRONT LEFT IMPACT SENSOR SIGNAL CIRCUIT OPEN
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OCCUPANT RESTRAINT CONTROLLER (ORC)
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Diagnostic Test
1.
VERIFY THAT DTC U0170-LOST COMMUNICATION W/UP-FRONT LEFT SATELLITE ACCELERATION SENSOR IS ACTIVE
NOTE:
Ensure the battery is fully charged.
Turn the ignition on.
With the scan tool, read ORC DTC.
Does the scan tool display active: U0170-LOST COMMUNICATION W/UP-FRONT LEFT SATELLITE ACCELERATION SENSOR?
Yes
No
2.
CHECK THE (R79) and (R81) FRONT LEFT IMPACT SENSOR SIGNAL AND GROUND CIRCUITS FOR A SHORT TO BATTERY
WARNING:
To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.
Disconnect the Front Left Impact Sensor connector.
Disconnect the ORC connectors.
Connect the ORC 8443-32-L Adaptor to the ORC connectors.
NOTE:
The IP Harness is always connected to the right side (C1) of the 8443-32-L Adapter.
WARNING:
To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.
Measure the (R79) Front Left Impact Sensor Signal cavity 1 and (R81) Front Left Impact Sensor Ground cavity 2 circuit voltage between the Front Left Impact Sensor connector and ground.
Is there any voltage present?
Yes
No
3.
CHECK THE (R79) AND (R81) FRONT LEFT IMPACT SENSOR CIRCUITS FOR A SHORT TO GROUND
WARNING:
To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.
Measure the resistance of the (R79) Front Left Impact Sensor Signal circuit cavity 2 and (R81) Front Left Impact Sensor Ground circuit cavity 1 between the Front Left Impact Sensor connector
and ground.
Is the resistance below 100K ohms?
Yes
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Repair the (R79) and (R81) Front Left Impact Sensor circuits for a short to ground.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
No
4.
CHECK THE (R79) AND (R81) FRONT LEFT IMPACT SENSOR CIRCUITS FOR A SHORT TOGETHER
Measure the resistance between the (R79) Front Left Impact Sensor Signal and (R81) Front Left Impact Sensor Ground circuits at the Front Left Impact Sensor connector.
Is the resistance below 100K ohms?
Yes
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Repair the (R79) and (R81) Front Left Impact Sensor circuits shorted together.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
No
5.
CHECK THE (R81) FRONT LEFT IMPACT SENSOR GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
Measure the resistance of the (R81) Front Left Impact Sensor Ground circuit cavity 1 between the Front Left Impact Sensor connector and the ORC 8443-32-L Adaptor cavity C1-28.
Is the resistance below 1 ohm?
Yes
No
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Repair the (R81) Front Left Impact Sensor 1 Ground circuit for an open or high resistance.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
6.
CHECK THE (R79) FRONT LEFT IMPACT SENSOR CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
Measure the resistance of the (R79) Front Left Impact Sensor Signal circuit cavity 2 between the Front Left Impact Sensor connector and the ORC 8443-32-L Adaptor cavity 29.
Is the resistance below 1 ohm?
Yes
No
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Repair the (R79) Front Left Impact Sensor Signal circuit for an open or high resistance.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
7.
CHECK OPERATION OF THE FRONT LEFT IMPACT SENSOR
Replace the Front Left Impact Sensor.
Reconnect the vehicle body harness to the impact sensor.
Remove any special tools or jumper wires and reconnect all previously disconnected components - except the Battery.
WARNING:
To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.
Connect the scan tool to the Data Link Connector - use the most current software available.
Use the scan tool and erase the stored codes in all airbag system modules.
Turn the Ignition Off, and wait 15 seconds before turning the Ignition On.
Wait one minute, and read active codes and if there are none present read the stored codes.
Did the active Front Left Impact Sensor DTC return?
Yes
No
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Repair is complete.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
8.
REPLACE THE OCCUPANT RESTRAINT CONTROLLER
WARNING:
To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.
WARNING:
If the airbag control module is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and serious
or fatal injury.
Disconnect the ORC 8443-32-L Adaptor.
If there are no possible causes remaining, view repair.
Repair
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Replace the Occupant Restraint Controller in accordance with Service Information.
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Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1.
9.
TEST FOR AN INTERMITTENT CONDITION
With the scan tool, record and erase all DTC from all Airbag modules.
If any ACTIVE codes are present they must be resolved before diagnosing any stored codes.
WARNING:
To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.
Using the wiring diagram / schematic as a guide, inspect the wiring and connectors.
Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
The following additional checks may assist you in identifying a possible intermittent problem.
Reconnect any disconnected components and harness connector.
WARNING:
To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.
With the scan tool monitor active codes as you work through the following steps.
WARNING:
To avoid serious or fatal injury, maintain a safe distance from all airbags while performing the following steps.
Wiggle the wiring harness and connectors of the related airbag circuit or component.
If codes are related to the Driver Airbag circuits, rotate the steering wheel from stop to stop.
If only stored codes return continue the test until the problem area has been isolated.
In the previous steps you have attempted to recreate the conditions responsible for setting active DTC in question.
Are any ACTIVE DTC present?
Yes
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Select the appropriate symptom from Symptom List.
No
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No problem found at this time. Erase all codes before returning vehicle to customer.