U0698: Lost Communication With Coolant Pump E

What it means

Communication with coolant pump E has been lost. The code identifies a communication fault; the pump’s function and the vehicle’s response depend on the vehicle design.

At a glance

• Usually lights the warning light of the system that lost communication
• The engine or gearbox may go into limp mode

How it works

Coolant pump E circulates coolant for a vehicle system assigned that pump by the manufacturer, such as an engine or thermal-management circuit. This code sets when the vehicle bus loses communication with pump E; the affected function and consequences depend on the vehicle’s design.

Common causes

Most likely first.

1. Bus wiring open or shorted
2. Module without power or ground
3. Module failed

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Record freeze-frame data and scan all modules for other pump, temperature, or communication codes to identify which system uses pump E.
2. Check live data for pump E’s communication status and, where available, its command, feedback, and the temperature of the circuit it serves.
3. Inspect pump E’s connector and bus wiring for loose connections, corrosion, chafing, or heat damage.
4. Check pump E’s specified power and ground, since a missing supply can prevent its controller from communicating.
5. Test the communication circuit for an open or short using the vehicle wiring diagram and manufacturer procedures.
6. If the bus wiring and supply are sound, assess pump E’s control module for failure.

Common fixes

• Reconnect or clean a loose or corroded pump E connector.
• Repair damaged or shorted bus wiring to pump E.
• Restore the pump’s power or ground connection.
• Replace coolant pump E if its wiring and supply are sound and its module has failed.

Can I keep driving?

If a temperature warning, overheating, or power limitation appears, stop safely and switch the vehicle off; the consequence depends on which circuit pump E serves. If there are no warnings, keep driving to a minimum and arrange prompt diagnosis.