Power Seats

U0020-CAN B BUS OFF PERFORMANCE

U0020 - Can B Bus Off Performance:

WHEN MONITORED
Continuously

SET CONDITION
The Memory Seat Module detects the (D55) CAN B Bus (+) circuit or (D54) CAN B Bus (-) circuit open.

POSSIBLE CAUSES
- (D55) CAN B BUS (+) circuit open
- (D54) CAN B BUS (-) circuit open
- Memory seat module

Diagnostic Test

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

Q: Does the scan tool display this DTC as active?

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. (D55) CAN B BUS (+) CIRCUIT OPEN




Turn the ignition off.
Disconnect the Memory Seat Module C1 harness connector.
Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.

Q: Is there any voltage present?

YES: Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Memory Seat Module.
Perform POWER SEAT SYSTEM VERIFICATION TEST-VER 1. Power Seat System Verification Test
NO: Repair the (D55) CAN B Bus (+) circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

3. (D54) CAN B BUS (-) CIRCUIT OPEN




Turn the ignition off.
Disconnect the Memory Seat Module C1 harness connector.
Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.

Q: Is there any voltage present?

YES: Inspect the wiring and connectors for damage or shorted circuits. If ok, replace the Memory Seat Module.
Perform POWER SEAT SYSTEM VERIFICATION TEST-VER 1. Power Seat System Verification Test
NO: Repair the (D54) CAN B Bus (-) circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test