P0355 on Cadillac Lyriq
Factory diagnostic protocol and troubleshooting wire for fault code P0355 specifically for the Cadillac Lyriq (2023–2026, Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP)).
1. Symptoms of P0355 on Cadillac Lyriq
When the Engine Control Module (ECM/PCM) on your Cadillac Lyriq (Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP)) logs fault code P0355, drivers commonly observe:
2. Most Likely Causes on Cadillac Lyriq
Historical warranty claims and technical repair bulletins for Cadillac Lyriq point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Cadillac Lyriq
Connect an OBD-II scan tool and record freeze frame sensor telemetry for code P0355 to note engine RPM, load, and voltage when the fault triggered. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Inspect the electrical connector and wiring harness related to P0355 for chafing, corrosion, moisture, or pin push-out. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Measure circuit voltage supply (12V B+ or 5V reference) and sensor/actuator resistance according to factory repair manual specifications. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Install a new OEM-grade replacement part, torque fasteners to factory spec, and ensure electrical locking tabs click firmly. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Clear all stored DTCs from vehicle memory and perform an OBD-II drive cycle to confirm the diagnostic monitor resets to 'Ready'. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Equipment for Diagnosing Cadillac Lyriq (P0355)
Direct-Fit Laser Iridium Spark Plugs (Set of 4/6)
Pre-gapped iridium spark plugs engineered to restore smooth combustion on Cadillac Lyriq.
Magnetic Swivel Spark Plug Socket Set
360-degree magnetic swivel socket prevents ceramic plug cracks inside deep engine spark wells.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Cadillac Lyriq
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Cadillac Lyriq:
4. Cadillac Lyriq P0355 FAQs
What causes code P0355 to trigger on a Cadillac Lyriq?
On the Cadillac Lyriq (Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP)), P0355 is most frequently caused by Dead Cylinder 5 ignition coil or Wiring damage.
Where is the OBD-II port located on my Cadillac Lyriq?
On the Cadillac Lyriq, the 16-pin DLC diagnostic connector is located Under driver steering column beneath knee bolster. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Cadillac Lyriq with code P0355?
No. Cylinder 5 ignition coil dead. Given that P0355 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.