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U0170 — Lost Communication With Restraints System Sensor A

Detailed page for trouble code U0170.

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Code

U0170

Generic U — Network/User

Lost Communication With Restraints System Sensor A

AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted communication wiring (CAN/LIN) between sensor A and restraints control module
  • Faulty restraint sensor A
  • Poor or corroded connector pins at the sensor, module, or splice
  • Loss of power or ground to the sensor or restraints control module
  • Faulty restraints control module (RCM/SRM) or gateway module
  • Damaged or missing termination resistor(s) on the vehicle bus

Symptoms

  • SRS/airbag warning lamp illuminated
  • Related restraints system features may be disabled or flagged in diagnostics
  • Stored U0170 and possibly other communication or restraints-related codes
  • Intermittent or permanent loss of sensor data when monitored with a scan tool

What to check

  • Visually inspect sensor A connector, harness, and nearby wiring for damage, corrosion, contamination, or pin push-out
  • Check for water damage or recent collision/repair evidence near the sensor or harness
  • Use a scan tool to verify U0170 and look for related codes and freeze frame data
  • Monitor live data/communication on the restraints network for presence of sensor A messages
  • Check power and ground circuits for the sensor and the restraints control module (verify proper voltages and good grounds)
  • Verify CAN/LIN bus continuity and termination resistor values at the module ends (typically two 120Ω in parallel → ~60Ω across CAN H/L)

Signal parameters

  • Typical CAN idle (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (each), differential ≈ 0 V; dominant state: CAN_H ≈ 3.5–3.75 V, CAN_L ≈ 1.25–1.5 V; differential ≈ 2–3 V (vehicle-specific)
  • CAN bus termination: ~60 Ω measured across CAN_H and CAN_L (two 120 Ω in parallel)
  • Common CAN bit rates: 250 kbps or 500 kbps (confirm vehicle specification)
  • If sensor uses LIN: idle ~battery voltage via pull-up, dominant low ≈ 0 V, typical LIN baud 19.2 kbps (vehicle-specific)
  • Sensor power: vehicle-specific (often switched 12 V with a fused feed) and chassis/return ground — verify nominal battery voltage at harness with ignition on

Diagnostic algorithm

  1. Safety first: follow SRS safety procedures — disconnect battery only per manufacturer guidance and observe required wait times before servicing airbag/SRS connectors. Use insulated tools and avoid unnecessary connector disturbance.
  2. Read and record codes and freeze-frame data with a capable scan tool. Note any additional communication or restraints codes.
  3. Visually inspect sensor A connector, wiring, and mounting. Look for corrosion, bent pins, pushed-out terminals, moisture, or physical damage.
  4. With ignition on (and following safety procedures), verify sensor power/ignition feed and ground at the sensor connector using a multimeter. Compare to vehicle nominal battery voltage and good ground.
  5. Backprobe CAN_H and CAN_L at the sensor connector and at the restraints control module. Verify idle voltages, dominance on bus activity, and correct termination resistance (~60 Ω). Use oscilloscope if available to view bus signals and noise.
  6. Monitor the restraints network with the scan tool. Attempt to request sensor data or view live messages. Perform a wiggle test on the harness and connectors while watching for dropouts or new codes.
  7. Check continuity between sensor pins and the restraints control module pins to detect opens or high-resistance connections. Also check for shorts to battery or ground.
  8. Inspect connectors and harness routing for chafing points, especially under seats and through seatbelt anchor areas. Repair any damaged wiring using proper solder/crimp and heat-shrink or OEM repair splices.
  9. If wiring and connectors test OK, consider replacing sensor A with a known-good unit or swapping with an identical known-good sensor (if applicable) to check for sensor failure. Re-scan for codes after replacement.
  10. If communication is still lost and wiring/sensor are good, inspect or test the restraints control module and gateway for faults; check module power/ground and perform reprogramming or module replacement only per OEM procedures.
  11. Clear codes and perform a functional test/road test and recheck for recurrence. Document repairs and verify SRS light behavior and absence of communication faults.

Likely causes

  • Disconnected or loose sensor connector at the seat or sensor location
  • Broken/chafed wiring harness in the seat or under-hood area
  • Corroded pins or moisture intrusion in connector
  • Faulty sensor A
  • Faulty or unpowered restraints control module

Fault status

⚠️ Status
U0170 — Lost Communication With Restraints System Sensor A. Communication with the specified restraints sensor is not detected by the restraints control module or network.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

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Code

U0170

HYUNDAI U — Network/User

Lost Communication With “Restraints System Sensor A”

AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted communication wiring (CAN/LIN) between sensor A and restraints control module
  • Faulty restraint sensor A
  • Poor or corroded connector pins at the sensor, module, or splice
  • Loss of power or ground to the sensor or restraints control module
  • Faulty restraints control module (RCM/SRM) or gateway module
  • Damaged or missing termination resistor(s) on the vehicle bus

Symptoms

  • SRS/airbag warning lamp illuminated
  • Related restraints system features may be disabled or flagged in diagnostics
  • Stored U0170 and possibly other communication or restraints-related codes
  • Intermittent or permanent loss of sensor data when monitored with a scan tool

What to check

  • Visually inspect sensor A connector, harness, and nearby wiring for damage, corrosion, contamination, or pin push-out
  • Check for water damage or recent collision/repair evidence near the sensor or harness
  • Use a scan tool to verify U0170 and look for related codes and freeze frame data
  • Monitor live data/communication on the restraints network for presence of sensor A messages
  • Check power and ground circuits for the sensor and the restraints control module (verify proper voltages and good grounds)
  • Verify CAN/LIN bus continuity and termination resistor values at the module ends (typically two 120Ω in parallel → ~60Ω across CAN H/L)

Signal parameters

  • Typical CAN idle (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (each), differential ≈ 0 V; dominant state: CAN_H ≈ 3.5–3.75 V, CAN_L ≈ 1.25–1.5 V; differential ≈ 2–3 V (vehicle-specific)
  • CAN bus termination: ~60 Ω measured across CAN_H and CAN_L (two 120 Ω in parallel)
  • Common CAN bit rates: 250 kbps or 500 kbps (confirm vehicle specification)
  • If sensor uses LIN: idle ~battery voltage via pull-up, dominant low ≈ 0 V, typical LIN baud 19.2 kbps (vehicle-specific)
  • Sensor power: vehicle-specific (often switched 12 V with a fused feed) and chassis/return ground — verify nominal battery voltage at harness with ignition on

Diagnostic algorithm

  1. Safety first: follow SRS safety procedures — disconnect battery only per manufacturer guidance and observe required wait times before servicing airbag/SRS connectors. Use insulated tools and avoid unnecessary connector disturbance.
  2. Read and record codes and freeze-frame data with a capable scan tool. Note any additional communication or restraints codes.
  3. Visually inspect sensor A connector, wiring, and mounting. Look for corrosion, bent pins, pushed-out terminals, moisture, or physical damage.
  4. With ignition on (and following safety procedures), verify sensor power/ignition feed and ground at the sensor connector using a multimeter. Compare to vehicle nominal battery voltage and good ground.
  5. Backprobe CAN_H and CAN_L at the sensor connector and at the restraints control module. Verify idle voltages, dominance on bus activity, and correct termination resistance (~60 Ω). Use oscilloscope if available to view bus signals and noise.
  6. Monitor the restraints network with the scan tool. Attempt to request sensor data or view live messages. Perform a wiggle test on the harness and connectors while watching for dropouts or new codes.
  7. Check continuity between sensor pins and the restraints control module pins to detect opens or high-resistance connections. Also check for shorts to battery or ground.
  8. Inspect connectors and harness routing for chafing points, especially under seats and through seatbelt anchor areas. Repair any damaged wiring using proper solder/crimp and heat-shrink or OEM repair splices.
  9. If wiring and connectors test OK, consider replacing sensor A with a known-good unit or swapping with an identical known-good sensor (if applicable) to check for sensor failure. Re-scan for codes after replacement.
  10. If communication is still lost and wiring/sensor are good, inspect or test the restraints control module and gateway for faults; check module power/ground and perform reprogramming or module replacement only per OEM procedures.
  11. Clear codes and perform a functional test/road test and recheck for recurrence. Document repairs and verify SRS light behavior and absence of communication faults.

Likely causes

  • Disconnected or loose sensor connector at the seat or sensor location
  • Broken/chafed wiring harness in the seat or under-hood area
  • Corroded pins or moisture intrusion in connector
  • Faulty sensor A
  • Faulty or unpowered restraints control module

Fault status

⚠️ Status
U0170 — Lost Communication With Restraints System Sensor A. Communication with the specified restraints sensor is not detected by the restraints control module or network.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

371

Browse 371 HYUNDAI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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Code

U0170

LAND ROVER U — Network/User

Lost communication with the A retention system sensor

AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted communication wiring (CAN/LIN) between sensor A and restraints control module
  • Faulty restraint sensor A
  • Poor or corroded connector pins at the sensor, module, or splice
  • Loss of power or ground to the sensor or restraints control module
  • Faulty restraints control module (RCM/SRM) or gateway module
  • Damaged or missing termination resistor(s) on the vehicle bus

Symptoms

  • SRS/airbag warning lamp illuminated
  • Related restraints system features may be disabled or flagged in diagnostics
  • Stored U0170 and possibly other communication or restraints-related codes
  • Intermittent or permanent loss of sensor data when monitored with a scan tool

What to check

  • Visually inspect sensor A connector, harness, and nearby wiring for damage, corrosion, contamination, or pin push-out
  • Check for water damage or recent collision/repair evidence near the sensor or harness
  • Use a scan tool to verify U0170 and look for related codes and freeze frame data
  • Monitor live data/communication on the restraints network for presence of sensor A messages
  • Check power and ground circuits for the sensor and the restraints control module (verify proper voltages and good grounds)
  • Verify CAN/LIN bus continuity and termination resistor values at the module ends (typically two 120Ω in parallel → ~60Ω across CAN H/L)

Signal parameters

  • Typical CAN idle (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (each), differential ≈ 0 V; dominant state: CAN_H ≈ 3.5–3.75 V, CAN_L ≈ 1.25–1.5 V; differential ≈ 2–3 V (vehicle-specific)
  • CAN bus termination: ~60 Ω measured across CAN_H and CAN_L (two 120 Ω in parallel)
  • Common CAN bit rates: 250 kbps or 500 kbps (confirm vehicle specification)
  • If sensor uses LIN: idle ~battery voltage via pull-up, dominant low ≈ 0 V, typical LIN baud 19.2 kbps (vehicle-specific)
  • Sensor power: vehicle-specific (often switched 12 V with a fused feed) and chassis/return ground — verify nominal battery voltage at harness with ignition on

Diagnostic algorithm

  1. Safety first: follow SRS safety procedures — disconnect battery only per manufacturer guidance and observe required wait times before servicing airbag/SRS connectors. Use insulated tools and avoid unnecessary connector disturbance.
  2. Read and record codes and freeze-frame data with a capable scan tool. Note any additional communication or restraints codes.
  3. Visually inspect sensor A connector, wiring, and mounting. Look for corrosion, bent pins, pushed-out terminals, moisture, or physical damage.
  4. With ignition on (and following safety procedures), verify sensor power/ignition feed and ground at the sensor connector using a multimeter. Compare to vehicle nominal battery voltage and good ground.
  5. Backprobe CAN_H and CAN_L at the sensor connector and at the restraints control module. Verify idle voltages, dominance on bus activity, and correct termination resistance (~60 Ω). Use oscilloscope if available to view bus signals and noise.
  6. Monitor the restraints network with the scan tool. Attempt to request sensor data or view live messages. Perform a wiggle test on the harness and connectors while watching for dropouts or new codes.
  7. Check continuity between sensor pins and the restraints control module pins to detect opens or high-resistance connections. Also check for shorts to battery or ground.
  8. Inspect connectors and harness routing for chafing points, especially under seats and through seatbelt anchor areas. Repair any damaged wiring using proper solder/crimp and heat-shrink or OEM repair splices.
  9. If wiring and connectors test OK, consider replacing sensor A with a known-good unit or swapping with an identical known-good sensor (if applicable) to check for sensor failure. Re-scan for codes after replacement.
  10. If communication is still lost and wiring/sensor are good, inspect or test the restraints control module and gateway for faults; check module power/ground and perform reprogramming or module replacement only per OEM procedures.
  11. Clear codes and perform a functional test/road test and recheck for recurrence. Document repairs and verify SRS light behavior and absence of communication faults.

Likely causes

  • Disconnected or loose sensor connector at the seat or sensor location
  • Broken/chafed wiring harness in the seat or under-hood area
  • Corroded pins or moisture intrusion in connector
  • Faulty sensor A
  • Faulty or unpowered restraints control module

Fault status

⚠️ Status
U0170 — Lost Communication With Restraints System Sensor A. Communication with the specified restraints sensor is not detected by the restraints control module or network.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

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