U058B

Code

Generic U — Network/User

Invalid Data Received From Transmission Fluid Pump Module B

Brand: Generic

Type: U — Network/User

Views: UK: 24 EN: 27 RU: 26

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Page language: EN

Causes

Corrupted or malformed CAN/LIN message from Transmission Fluid Pump Module B
Intermittent or open/shorted wiring or poor connector at the pump module
Low or noisy supply/ground at the pump module or receiving module
CAN bus termination or bus loading problem
Software/firmware mismatch or corrupted calibration in the pump module or receiving ECU
Failed or failing Transmission Fluid Pump Module B

Symptoms

Transmission pump may not run or runs intermittently
Transmission performance issues: hard shifts, delayed engagement, limp mode
Warning lights or messages related to transmission or powertrain
Multiple network-related DTCs present or loss of data from the pump module on a scan tool
No communication with Transmission Fluid Pump Module B when queried
Erratic or inconsistent sensor/pressure readings related to lubrication/cooling

What to check

Use a scan tool to read all stored codes and freeze-frame data; note any related network codes
Confirm ability to communicate with Transmission Fluid Pump Module B (module present on network)
Inspect connectors and wiring harness at the pump module and receiving module for corrosion, damage, or loose pins
Measure battery voltage and check for voltage drops at the module power and ground pins
Backprobe CAN high and CAN low at the pump module and at the receiving ECU to verify presence of messages
Check CAN bus termination resistance (typically ~60 ohms across CAN H and CAN L) with ignition off

Signal parameters

Bus type: vehicle network CAN (or vehicle-specific network) between pump module and receiving ECU
Expected idle voltages: CAN_H and CAN_L ~2.5 V each (dominant state alters voltages) — verify with reference values for the vehicle
Message periodicity: pump-status messages typically periodic (e.g., several Hz) or sent on request — compare to known-good
Message content (typical): status byte(s), pump command/feedback, pressure/temperature values, plus checksum/CRC
Validity checks: expected message length, checksum or CRC, source address/ID, and plausibility ranges for fields

Diagnostic algorithm

Connect a capable scan tool. Record U058B plus any other U- or P-codes and freeze-frame data. Note whether the pump module is listed and its reported VIN/address.
Confirm battery voltage is within specification. Perform a wiggle test on power and ground leads while monitoring voltage to detect intermittent drops.
Attempt to communicate directly with Transmission Fluid Pump Module B. If no response, check connector pinouts and secure connections.
Visually inspect the pump module connector and harness for corrosion, bent pins, chafing, or water intrusion. Repair any damage.
With module connected, backprobe CAN_H and CAN_L at the pump module and at the receiving ECU. Use an oscilloscope or logic analyzer to verify correct levels and clean CAN waveforms and to confirm messages from the pump module are present and periodic.
Check CAN bus termination resistance (with ignition off) across CAN_H and CAN_L. Investigate unexpected resistance values or multiple termination points.
If corrupted messages are observed, isolate by disconnecting the pump module and rechecking bus traffic for noise or bus contention. Reconnect and observe changes.
Verify module software/calibration and VIN/addresses. If module was recently replaced or reprogrammed, confirm correct part and calibration loaded.
If wiring and bus look good but the module still transmits invalid data, consider re-flashing the module software or replacing the pump module per manufacturer procedures.
After repairs or software updates, clear codes and perform function tests and a road test to confirm the issue is resolved and the code does not return.

Likely causes

Faulty wiring/poor connector between pump module and vehicle network
Pump module sending malformed messages (software fault or internal hardware failure)
Loss of proper supply or ground to the pump module causing corrupted transmission
Bus contention or improper termination on the CAN bus affecting message integrity
Module configuration mismatch after replacement or software update