P26C8 on Cadillac
Chassis Control Module 1 Requested MIL Illumination
P26C8 on Cadillac vehicles indicates chassis control module 1 requested mil illumination. Au7o has documented this code across 1 Cadillac model — most commonly on XT5. An ISO/SAE-controlled powertrain code (not GM-proprietary, though it is most often reported on GM vehicles — Chevrolet, GMC, Buick, Cadillac). It does not describe a failure of its own: chassis control module 1 detected a fault it considers worthy of driver notification, sent a serial data message asking the engine control module to illuminate the MIL, and the ECM logged P26C8 to record that request. The real fault is stored as a separate DTC inside the chassis control module — the module that oversees chassis-side functions such as stability/traction control and electronically controlled suspension. Do not chase this code directly: scan all modules, find the DTC the chassis module actually set, and diagnose that. Typical repair costs on Cadillac range from $150 to $800, depending on the specific model and root cause.
Common Causes of P26C8
- •An unrelated fault stored in the chassis control module (the actual root cause)
- •Faults in chassis-side systems the module oversees — stability control, traction control, magnetic ride/electronic suspension
- •Outdated chassis control module software needing a reprogram
- •Serial data (CAN) bus wiring or connector faults between modules
- •Low system voltage or a weak battery triggering module faults
- •Failed chassis control module
P26C8 on Cadillac by Model
Cadillac XT5(1 issue)
- Electronic Gear Selector Park-Switch Fault - Persistent 'Shift to Park' Message / Won't Power Down (TSB 19-NA-206)2017-2019
A faulty park-position switch inside the electronic shifter assembly intermittently fails to signal that the vehicle is in Park. This produces a persistent 'Shift to Park' message on the driver information center even when the lever is physically in Park, and the vehicle may refuse to fully power down, staying in accessory mode and draining the 12V battery overnight. Owners report shifter codes such as P07BE and P26C8. GM addressed the concern with TSB 19-NA-206. This is an electronic-shifter/electrical failure, separate from internal transmission shudder/harsh-shift issues.
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View P26C8 across all makes →Frequently Asked Questions
What does P26C8 mean on Cadillac?▼
P26C8 stands for "Chassis Control Module 1 Requested MIL Illumination." An ISO/SAE-controlled powertrain code (not GM-proprietary, though it is most often reported on GM vehicles — Chevrolet, GMC, Buick, Cadillac). It does not describe a failure of its own: chassis control module 1 detected a fault it considers worthy of driver notification, sent a serial data message asking the engine control module to illuminate the MIL, and the ECM logged P26C8 to record that request. The real fault is stored as a separate DTC inside the chassis control module — the module that oversees chassis-side functions such as stability/traction control and electronically controlled suspension. Do not chase this code directly: scan all modules, find the DTC the chassis module actually set, and diagnose that. On Cadillac specifically, this code is documented across 1 model.
What causes P26C8 on Cadillac vehicles?▼
Common causes on Cadillac: An unrelated fault stored in the chassis control module (the actual root cause), Faults in chassis-side systems the module oversees — stability control, traction control, magnetic ride/electronic suspension, Outdated chassis control module software needing a reprogram, Serial data (CAN) bus wiring or connector faults between modules, Low system voltage or a weak battery triggering module faults. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P26C8 on a Cadillac?▼
Repair costs on Cadillac range from $150 to $800, depending on the specific model and root cause.
Which Cadillac models have P26C8 documented?▼
Au7o has documented P26C8 on 1 Cadillac model: XT5.