U010A: Lost Communication With Exhaust Gas Recirculation Control Module A

What it means

A control module has lost communication with exhaust gas recirculation control module A. EGR operation may be affected on vehicles that use this module.

At a glance

• Affects emissions; the car can fail an emissions test

How it works

Exhaust gas recirculation control module A manages or reports an EGR system on vehicles that use a dedicated module. EGR recirculates some exhaust gas to help control combustion emissions, and the module communicates its status over the network. U010A sets when a reporting module stops receiving expected messages from EGR control module A.

Common causes

Most likely first.

1. Loss of module power or ground
2. Open, shorted, or damaged communication wiring or connector
3. Module or gateway fault

Symptoms

• Warning lights or messages
• Communication faults in other modules
• Engine performance or emissions symptoms may occur

How to diagnose it

1. Scan all modules for U010A and related EGR or network codes, and save freeze-frame data such as engine load and temperature.
2. Check for EGR warnings, rough running, or emissions-related symptoms, and see whether live data from EGR control module A is available.
3. Inspect module A's connector and harness, tracing the wiring to the EGR equipment for corrosion, heat damage, looseness, or chafing.
4. Check module A's power and ground circuits against the manufacturer's specification.
5. Test the communication wiring for opens, shorts, or poor connections using the vehicle wiring information.
6. If power, ground, and network wiring are sound, use vehicle-specific diagnostics to check module A and the EGR system before replacing parts.

Common fixes

• Secure or clean a loose or corroded EGR control module A connector.
• Repair damaged wiring or a poor ground at module A.
• Restore the module's power supply and correct the cause of a failed fuse.
• Repair a gateway or network fault if circuit testing points to it.
• Replace or program EGR control module A only after its circuits and EGR components have been checked.

Can I keep driving?

If the engine runs normally, cautious short-distance driving is generally possible, but emissions performance may be affected. Stop if the engine runs very poorly or loses power, and avoid driving in a way that worsens those symptoms.