Heated Seats

U0019-CAN B BUS - HSM

For complete wiring diagram refer to the wiring section.

WHEN MONITORED
Continuously.
SET CONDITION
Whenever the Can B Bus (+) or B Bus (-) circuit is open, shorted to voltage or shorted to ground, this code will set.

POSSIBLE CAUSES
- CAN B BUS DTC's IN Front Control Module
- (D54) CAN B BUS (-) Circuit Open
- (D55) CAN B BUS (+) Circuit Open
- Heated Seat Module

DIAGNOSTIC TEST

1. TEST FOR INTERMITTENT CONDITION
Turn the ignition on.
With the scan tool, record and erase DTC's Cycle the ignition from on to off 3 times.
Turn the ignition on.
With the scan tool, read DTC's.

Q: Does the scan tool display U0019 CAN B BUS CIRCUIT?

YES: Go To 2
NO: The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

2. CHECK FRONT CONTROL MODULE DTC's
With the scan tool, read Front Control Module DTC's

Q: Does the scan tool display any CAN B BUS DTC's -ACTIVE?

YES: Refer to the symptom list for problems related to Communication in the ELECTRICAL.- ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSES section.
NO: Go to 3

3. CAN B BUS (+) CIRCUIT OPEN Turn the ignition off.
Disconnect the Heated Seat Module connector.
Disconnect the Front Control Module C1 connector.
Measure the resistance of the (D55) Can B Bus (+) circuit between the Front Control Module C1 connector and the Heated Seat Module connector.

Q: Is the resistance below 2.0 ohms?

YES: Go To 4
NO: Repair the Can B Bus (+) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. CAN B BUS (-) CIRCUIT OPEN
Measure the resistance of the (D54) Can B Bus (-) circuit between the Front Control Module C1 connector and the Heated Seat Module connector.

Q: Is the resistance below 2.0 ohms?

YES: Replace the Heated Seat Module. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the Can B Bus (-) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test