Pinpoint Test AE: Invalid Or Missing Can (Controller Area Network) Data From The Pcm (Powertrain Control Module)

WARNING: This page is about a different car, the 2022 Ford Transit-350 HD, 2022 Ford Transit-350, 2022 Ford Transit-250, 2022 Ford Transit-150, and 2022 Ford E-Transit. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Horn/Cigar Lighter for schematic and connector information.

Normal Operation and Fault Conditions

On vehicles equipped with a 3.5L engine, the TCS in an internal part of the PCM. With the ignition ON, the PCM sends messages to the ABS module over the HS-CAN. If the ABS module does not receive these messages within the specified time frame, the ABS module sets DTCs. This can be due to a PCM failure, a circuit failure on the HS-CAN or an excessive load on the network.

The CCM is an internal component of the PCM. With the ignition ON, the PCM sends messages to the ABS module through the BCM over the HS-CAN. If the ABS module does not receive these messages within the specified time frame, the module sets a DTC. This can be due to a PCM failure, a circuit failure on the HS-CAN or an excessive load on the network.

For information on the messages sent to the ABS module by the PCM, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description . .

The stoplamp switch (also known as the brake pedal switch, BPP switch and BOO switch) contains 2 sets of contacts, one set for a voltage signal and the other set for a ground signal.

For the voltage signal input, the stoplamp switch receives voltage at all times from the BCM. When the brake pedal is applied, the normally open switch closes and routes voltage to the BCM and the PCM.

For the ground signal input, the stoplamp switch receives a voltage signal from the PCM. The voltage signal is routed to ground through the normally closed switch. When the brake pedal is applied, the normally closed switch opens, interrupting the voltage signal from the PCM.

When the PCM receives these inputs it sends a message on the HS-CAN to the ABS module and other modules.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U0401:00	Invalid Data Received from ECM/PCM A: No Sub Type Information	This DTC sets when the ABS module receives invalid data in any of the following messages: accelerator pedal, brake pedal, driven wheel torque or neutral tow status.

Possible Sources

Network communication concern
Battery or charging system concerns
Stoplamp switch
PCM
ABS module

NOTE: There is no fault with the ABS module.

AE1 CHECK DATA FROM PCM (POWERTRAIN CONTROL MODULE)

A DTC has been set which has the following description:
- Invalid Data Received From the PCM.

Ignition ON.

Clear the ABS DTCs.

Ignition OFF.

Ignition ON.

Wait at least 1 minute.

Using a diagnostic scan tool, retrieve all DTCs from the ABS module. NOTE: DTCs may be displayed from previous diagnostic actions.

Did the DTCs return?

Yes	Invalid or Missing CAN data from the PCM. Check the CAN bus and terminating resistor (60 ohm) at the OBD connector. Check CAN bus circuit. Check for other failures in the PCM. Notice: Do not replace the ABS module.

No	Return the vehicle to the customer. If the fault reoccurs inform the customer to note any relevant conditions at the time of the fault. The test is now exiting.