U017E

Code

Generic U — Network/User

Lost Communication With Seat Belt Pretensioner Module A

Brand: Generic

Type: U — Network/User

Views: UK: 27 EN: 95 RU: 35

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or shorted CAN bus wiring between pretensioner module and network
Faulty or corroded connector at the seat belt pretensioner module
Loss of module power or ground (fused power, battery connection, chafe)
Failed seat belt pretensioner module
Network termination fault (missing or damaged 120 Ω resistors)
Intermittent wiring due to chafing or connector movement

Symptoms

SRS / airbag warning lamp illuminated
Seat belt pretensioner indicator or related warning message
Pretensioner may not deploy in a crash (safety risk)
Certain safety features disabled or limited
Stored U017E and possibly related U0xxx or B0xxx SRS codes
No communication with pretensioner module via scan tool

What to check

Retrieve all stored codes and freeze frame with a capable scan tool (include SRS/airbag and network pages)
Verify ability to communicate with other modules on the same CAN bus (BCM, ECM, SRS ECU)
Visually inspect connectors and wiring at seat belt pretensioner module for damage, corrosion, or disconnection
Check module power (battery/ignition feed) and ground with DVOM while backprobing (respect SRS safety procedures)
Measure CAN_H and CAN_L voltages at the pretensioner module connector with ignition ON
Measure resistance across CAN_H and CAN_L with ignition OFF (expect ~60 Ω with two 120 Ω terminators)

Signal parameters

CAN bus idle (recessive): CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (difference ≈ 0 V)
CAN bus dominant: CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (difference ≈ 2.0 V) during transmission
Typical bus resistance between CAN_H and CAN_L with two terminators: ≈ 60 Ω
Open circuit on CAN will show very high resistance (OL) between H and L or inconsistent voltage levels
Short to battery: CAN line near ≈ 12 V; short to ground: near 0 V

Diagnostic algorithm

Connect an advanced scan tool and record U017E and any related codes (SRS and U-codes). Note freeze frame and mileage.
Attempt to communicate directly with the Seat Belt Pretensioner Module A. Confirm 'no response' or intermittent response.
Check for service actions or crash flags that could disable the module. If crash-data present, follow manufacturer crash procedures.
Visually inspect the pretensioner module connector and harness routing for damage, moisture, pin corrosion, bent pins or aftermarket splices.
With ignition ON, measure module power feed(s) and ground at the connector. Compare to battery voltage and chassis ground. Repair blown fuse, open, or bad ground as needed.
With ignition ON, backprobe CAN_H and CAN_L at the module connector. Verify idle voltages (~2.5 V) and that differential transitions occur when other modules communicate. If voltages are incorrect, trace wiring toward the bus.

Likely causes

Damaged connector or wiring at pretensioner module (open/short)
Loss of module power or ground
CAN bus termination or short to battery/ground on CAN lines
Failed pretensioner module
Fault in another module on the same CAN network

Fault status

⚠️ Status

Lost communication with Seat Belt Pretensioner Module A — module not responding on CAN bus. May be wiring, power/ground, termination, or module fault.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-4 hours