U1412

U1412-IMPLAUSIBLE VEHICLE SPEED SIGNAL RECEIVED

U1412-Implausible Vehicle Speed Signal Received:

WHEN MONITORED
Ignition on.

SET CONDITION
The PCM gets an implausible signal over the CAN C circuit from the ABS Module or FCM (NON-ABS). The circuit is continuously monitored.

POSSIBLE CAUSES
- CAN C BUS circuit shorted
- CAN C BUS circuit open
- ABS module
- PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Theory of Operation
The ABS Module or FCM (NON-ABS) sends vehicle speed information over the CAN C Bus circuit to the PCM.

Diagnostic Test

1. ACTIVE DTC

NOTE: Diagnose all CAN B and C communication failures before continuing.

Ignition on, engine not running.
With a scan tool, read DTCs.

Q: Is the U1412-IMPLAUSIBLE VEHICLE SPEED SIGNAL RECEIVED active at this time?

YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT IS ACTIVE

Continue reading DTCs.

Q: Is the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT ACTIVE at this time?

YES: Refer to the Diagnostic Procedure for the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT. Testing and Inspection
NO: Go To 3

3. ABS MODULE IS ACTIVE ON THE CAN C BUS

With the scan tool, select ECU View.
Verify that the ABS Module is active on the bus.

Q: Is the ABS Module active on the bus?

YES: Go To 4
NO: Refer to Body Control Systems for No Response diagnostic procedures. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. ACTIVE DTCS IN THE FCM

With the scan tool, select ECU View and select FCM.
With the scan tool, read active DTCs.

Q: Is the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT ACTIVE in the FCM at this time?

YES: Refer to Body Control Systems for U0001 diagnostic procedures. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test