Exhaust Aftertreatment Control Module Signal 1
This code indicates a fault in the signal from the exhaust aftertreatment control module.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The exhaust aftertreatment control module (also known as the aftertreatment control unit) is responsible for managing systems like DPF regeneration or SCR operation. If it fails to send proper signals, it can cause emissions issues.
What the computer is actually seeing
The engine control unit (ECU) is monitoring the signals from the exhaust aftertreatment control module. It expects these signals to be within a certain voltage range (usually 0-5 volts) and responds if the values fall outside of this range, indicating a fault.
What a healthy reading looks like
The expected voltage from the control module signal should be between 0.5V to 4.5V under normal operating conditions.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the wiring and connectors between the exhaust aftertreatment control module and the engine control unit for damage or corrosion. Fix as necessary.
- 22. Measure the voltage output from the exhaust aftertreatment control module using a multimeter. Ensure it falls within the expected range (0.5V to 4.5V). If out of range, proceed to next step.
- 33. If the voltage is out of spec, inspect the module for any signs of failure or damage. If necessary, replace the exhaust aftertreatment control module.
- 44. Reconnect everything and clear the fault codes. Drive the vehicle to see if the code returns.
Common causes
- Wiring harness issues (frayed or shorted wires)
- Faulty exhaust aftertreatment control module
- Poor connections at the module or ECU
- Software issues in the module
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but you may have increased emissions and possibly reduced performance. Fix it soon.
Will this code come back after I clear it?
It might if the underlying issue isn't resolved, especially if it’s a wiring or module problem.
Why does this code pair with others like SPN 5760?
They often indicate related issues with the aftertreatment system and signal communication paths.
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