U1107

U1107-ECU IN SINGLE-WIRE MODE - HSM

U1107-ECU In Single-Wire Mode - HSM:

WHEN MONITORED
Continuously.

SET CONDITION
This code will set if either the Can B Bus (+) or (-) circuits are open.

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 three times.
Turn the ignition on.
With the scan tool, read DTC's.

Q: Does the scan tool display U1107 ECU IN SINGLE-WIRE MODE?

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 Manufacturer Code Charts for problems related to Communication.
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