Code
U2202
OPEL
U — Network/User
CAN-Bus No Communication with CDC (CD-Changer)
Views:
UK: 4
EN: 5
RU: 4
AI status
Completed
Completed
100%
Causes
- Loose, corroded or disconnected connector at the CD changer
- No power or ground to the CD changer (fuse, wiring, ground strap)
- Open, shorted or intermittent CAN bus wiring between CDC and network
- CAN bus short to battery or chassis ground
- Missing or bad CAN termination (open or double termination)
- Failed CAN transceiver in CDC or in another module on same bus
Symptoms
- CD changer not recognized by radio or head unit
- No CD changer control or playback functions from head unit
- Communication error or module missing messages on diagnostic tool
- Other modules on same CAN segment may show intermittent faults
- Possible radio/head unit errors or loss of related features
What to check
- Use a scan tool to confirm U2202 and check for other related network faults
- Verify power and ground at the CD changer connector (battery voltage on supply pin, good ground reference)
- Check relevant fuses for the radio/CD changer circuit
- Measure CAN bus voltages at CDC connector: CAN H and CAN L with ignition ON
- Measure termination resistance between CAN H and CAN L with ignition OFF (~60 Ω)
- Inspect wiring harness and connectors for damage, corrosion, water entry, or pin damage
Signal parameters
- CAN bus recessive voltage (common mode): approx. 2.0–2.75 V on CAN H and CAN L
- CAN dominant voltages: CAN H ≈ 3.5–4.0 V, CAN L ≈ 0.5–1.5 V (when switching)
- Bus termination resistance: ≈ 60 Ω measured between CAN H and CAN L (when ignition OFF and modules asleep)
- Typical CAN data rates: 250–500 kbps depending on vehicle model
- No network messages or module address response from CDC when scanned
Diagnostic algorithm
- Confirm DTC: Connect a capable diagnostic scanner and verify U2202, record freeze frame and related network codes.
- Visual inspection: Inspect CD changer connector and wiring for corrosion, water ingress, rodent damage, or broken insulation. Repair as needed.
- Power/ground check: With ignition ON, verify battery voltage at the CD changer power pin and a good ground at the chassis side of the connector. Replace blown fuses.
- CAN voltage check: Probe CAN H and CAN L at the CD changer connector. Verify recessive and dominant voltages roughly match expected ranges.
- Termination check: With ignition OFF (modules asleep), measure resistance between CAN H and CAN L — expect ≈ 60 Ω. Significant deviation indicates missing or extra terminator or open circuit.
- Wiring continuity/shorts: If voltages or termination are wrong, check continuity of CAN H and CAN L back to gateway/module and check for shorts to battery or ground.
- Module communication: Try to communicate with the CD changer via scan tool. If no response but wiring and power are good, suspect module failure or internal CAN transceiver issue.
- Isolate by substitution: If possible, swap with a known-good CD changer or temporarily disconnect other devices on same bus to see if fault clears.
- Software/configuration: Confirm module addressing and software version if applicable; reflash or reinitialize per manufacturer procedure where needed.
- Repair and verify: Repair wiring/connectors or replace fuse/module as indicated. After repair, clear codes and perform a test drive/communication check to confirm the fault does not return.
Likely causes
- Blown or removed fuse supplying the CD changer
- Disconnected/poor connector at CD changer (pin corrosion, bent pins)
- Open/short in CAN High or CAN Low conductors to the CD changer
- Failed CD changer CAN transceiver or internal module fault
- Bus termination resistor open (incorrect resistance between CAN H and L)
Fault status
Status
No communication with CD-Changer over CAN bus (CDC not responding).
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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