P1693: The "Ghost" Code That Confuses Everyon
You scan your truck, and P1693 pops up. You look for a broken sensor, a loose wire, or a bad fuse, but you find nothing. That’s because P1693 isn't usually the problem—it’s just the messenger.
What Does P1693 Actually Mean?
P1693 is a classic example of why generic OBD2 definitions fail. Depending on what you are driving, this code changes its identity completely.
🚛 For Dodge Ram (Cummins Diesel) Owners:
"Turbo Charge Control Circuit Malfunction" (Generic) vs. "DTC Detected in Companion Module" (Real meaning)
This is the most common confusion. On a 2nd Gen Dodge Ram (24V Cummins), P1693 is a "Companion Code."
Your truck has two main computers: the PCM (Powertrain CoCodentrol Module) and the ECM (Engine Control Module). P1693 is simply the PCM saying: "Hey, I'm fine, but the ECM has a problem. Go ask him."
🚗 For Hyundai / Kia Owners:
"Immobilizer Transponder Error"
Here, the code is specific. It usually means the car isn't detecting the chip in your key properly, or the "Smartra" unit is failing. If you have this code, your car likely cranks but won't start.
The Diagnostic Gap: Why Basic Scanners Miss the Point
This is where things get tricky. If you are using a basic $40 code reader on a Dodge, it might only communicate with the PCM. It sees P1693, shows it to you, and stops there.
It doesn't "talk" to the Cummins ECM to find out what the actual hidden code is (like a VP44 injection pump failure or a map sensor issue).
You Don't Need a Part, You Need "Topology"
To solve P1693, you don't replace a "P1693 sensor" because it doesn't exist. You need a tool that can scan multiple modules simultaneously to see the full picture.
This is a scenario where the iCarsoft CR Ultra P proves its value naturally. It uses Module Topology to show you the status of every computer in the vehicle—PCM, ECM, BCM, and Immobilizer—on a single screen.
(If you aren't familiar with how Topology Mapping works, we break it down simply in our video overview of the CR Ultra P here.)
How to Clear P1693 (Step-by-Step)
If you drive a Dodge (Cummins):
- Deep Scan: Use the CR Ultra P to enter the "Cummins Engine" module directly (not just standard OBDII).
- Find the Real Code: You will likely find a second code hiding there (e.g., P0216 Fuel Injection Pump). That is your actual problem.
- The Fix: Repair the issue causing the hidden code.
- The Reset: You must clear codes from BOTH the PCM and the ECM. If you only clear one, P1693 will pop right back up because the modules talk to each other.
If you drive a Hyundai/Kia:
- Key Check: Do you have a spare key? Try it. If the code vanishes, your original key's transponder chip is dead.
- Antenna Ring: Check the "Immobilizer Coil" around the ignition cylinder. Use the CR Ultra P to view "Immobilizer Status" in Live Data. It should switch to "Key Learned" when you insert the key.
Common Questions
Can I ignore code P1693?
No. Since P1693 is a "messenger," ignoring it means you are ignoring a deeper problem hidden in another system. On a diesel truck, this could be an early warning of a fuel pump failure.
I replaced the sensor but P1693 came back. Why?
Remember, P1693 isn't a sensor failure. If you replaced a part based on a generic definition (like a turbo sensor), you likely fixed a part that wasn't broken. You need to scan the companion module to find the real fault.
