Redundant SCR Module Communication Failure
The SCR module isn't communicating properly with the ECM.
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 system is supposed to check the operation of the SCR (Selective Catalytic Reduction) system to reduce emissions, and it isn't getting the expected signals back from the SCR control module.
What the computer is actually seeing
The Engine Control Module (ECM) expects to receive a data signal from the SCR module that shows the status of the SCR system. If the ECM doesn't receive this data within a certain timeframe (typically less than 100 milliseconds), it triggers this fault code.
What a healthy reading looks like
Voltage levels from the SCR module should be around 0.5V to 4.5V depending on the signal; the communication is typically through a CAN bus with a specified frequency of 250 kbps.
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 all wiring and connectors between SCR module and ECM for damage or corrosion. If found, repair or replace as needed. Decision point: Are connections good? If yes, proceed to next step. If no, repair connections and retest.
Common causes
- Faulty SCR control module
- Wiring issues between SCR module and ECM
- Failed CAN bus communication
- Water intrusion in connectors
- Poor ground connection
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s safer to avoid driving until the issue is resolved to prevent further emissions system damage.
Will this code come back after clearing?
It may come back if the underlying issue is not addressed.
Why does it seem related to other SCR codes?
These codes often stem from similar issues in the SCR system and can indicate multiple faults.
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