C1288 on Cadillac Lyriq
Factory diagnostic protocol and troubleshooting wire for fault code C1288 specifically for the Cadillac Lyriq (2023–2026, Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP)).
1. Symptoms of C1288 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 C1288, 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
Monitor brake pressure transducer PID. It should read near 0 bar unpressed and climb smoothly to 80+ bar when pressing pedal. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Unplug ABS connector and check for bent pins or brake fluid contamination. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Replace the ABS HCU / pump assembly or send unit to a certified rebuilder to replace the internal pressure transducer. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Run scan tool automated bleed procedure to purge air from ABS valves, then bleed all 4 calipers. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Clear DTCs and road test to verify AdvanceTrac operation. on the Cadillac Lyriq equipped with Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP).
Equipment for Diagnosing Cadillac Lyriq (C1288)
Cadillac Lyriq OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Cadillac Lyriq.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
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 C1288 FAQs
What causes code C1288 to trigger on a Cadillac Lyriq?
On the Cadillac Lyriq (Ultium Dual Motor AWD (500HP / 450 lb-ft) / Single Motor RWD (340HP)), C1288 is most frequently caused by Failed internal brake pressure transducer inside the ABS Hydraulic Control Unit (HCU) or Corroded pins in ABS module electrical connector.
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 C1288?
Caution. Normal hydraulic brakes work, but ABS, Traction Control, and AdvanceTrac are disabled. Given that C1288 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.