U1530 on Cadillac
K9 Body Control Module Lost Communication with M35P Window Motor Module - Passenger / M74P Window Motor - Passenger on LIN Bus
U1530 on Cadillac vehicles indicates k9 body control module lost communication with m35p window motor module - passenger / m74p window motor - passenger on lin bus. Au7o has documented this code across 1 Cadillac model — most commonly on XTS. The Body Control Module (K9) is the LIN master for the door/window motor modules. U1530 sets when the BCM stops receiving the expected LIN response frames from the passenger window motor module (M35P) or passenger window motor (M74P). GM groups it with the whole U1500-U15FF common-LIN family under one diagnostic procedure. It matters for parasitic-drain complaints because a LIN slave that will not answer, or that keeps re-driving the bus, prevents the BCM from completing its bus-quiet check and keeps the network — and therefore the modules on it — from entering sleep mode. Typical repair costs on Cadillac range from $200 to $900, depending on the specific model and root cause.
Common Causes of U1530
- •Failed passenger window motor module / window motor with integrated LIN electronics
- •Open, shorted or high-resistance LIN circuit between the BCM and the passenger door module — commonly a broken wire in the door-jamb harness boot
- •Water intrusion or corrosion at the door connector or inside the door module
- •Loss of ignition/battery feed or ground to the window motor module
- •Body Control Module fault or software concern
U1530 on Cadillac by Model
Cadillac XTS(1 issue)
- Parasitic Battery Drain / Modules Not Entering Sleep Mode2013-2019
XTS owners frequently report the 12V battery going dead overnight or after a few days of sitting, caused by a control module failing to enter sleep mode and continuing to draw current with the ignition off. Common culprits on this platform include the radio/CUE (infotainment) module and the BCM. Repeated deep discharges then prematurely kill the battery and can trigger low-state-of-charge warnings and start-stop faults. GM issued service information for low-battery-state-of-charge conditions on 2018-2019 XTS/ATS/CTS.
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View U1530 across all makes →Frequently Asked Questions
What does U1530 mean on Cadillac?▼
U1530 stands for "K9 Body Control Module Lost Communication with M35P Window Motor Module - Passenger / M74P Window Motor - Passenger on LIN Bus." The Body Control Module (K9) is the LIN master for the door/window motor modules. U1530 sets when the BCM stops receiving the expected LIN response frames from the passenger window motor module (M35P) or passenger window motor (M74P). GM groups it with the whole U1500-U15FF common-LIN family under one diagnostic procedure. It matters for parasitic-drain complaints because a LIN slave that will not answer, or that keeps re-driving the bus, prevents the BCM from completing its bus-quiet check and keeps the network — and therefore the modules on it — from entering sleep mode. On Cadillac specifically, this code is documented across 1 model.
What causes U1530 on Cadillac vehicles?▼
Common causes on Cadillac: Failed passenger window motor module / window motor with integrated LIN electronics, Open, shorted or high-resistance LIN circuit between the BCM and the passenger door module — commonly a broken wire in the door-jamb harness boot, Water intrusion or corrosion at the door connector or inside the door module, Loss of ignition/battery feed or ground to the window motor module, Body Control Module fault or software concern. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U1530 on a Cadillac?▼
Repair costs on Cadillac range from $200 to $900, depending on the specific model and root cause.
Which Cadillac models have U1530 documented?▼
Au7o has documented U1530 on 1 Cadillac model: XTS.