P1603 Mazda Code - Engine Control Module Incorrect Immobilizer Code
Quick Answer
Battery positive voltage is supplied to the Engine Control Module (ECM) even when the ignition switch is OFF for use by the Diagnostic Trouble Code (DTC) memory and air–fuel ratio adaptive control value memory, etc. Common causes include Immobilizer word code not programmed, Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1603 Mazda indicates Engine Control Module Incorrect Immobilizer Code.
- Common causes
- Common causes include Immobilizer word code not programmed, Faulty Engine Control Module (ECM), Engine Control Module (ECM) harness is open or shorted.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1603 Mazda Description
What are the Possible Causes of the DTC P1603 Mazda?
- Immobilizer word code not programmed
- Faulty Engine Control Module (ECM)
- Engine Control Module (ECM) harness is open or shorted
- Engine Control Module (ECM) circuit poor electrical connection
How to Fix the DTC P1603 Mazda?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1603 Mazda code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P1603 Mazda code?
Need more information on how to fix the P1603 Mazda code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1603 Mazda code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1603 Mazda Code
1. What does the OBDII code P1603 mean on a Mazda?
P1603 indicates that the Engine Control Module (ECM) has detected an incorrect or mismatched immobilizer code, preventing the engine from starting.
2. What are the common symptoms of the P1603 code in a Mazda?
Symptoms include the engine not starting, the immobilizer warning light staying on, or intermittent starting issues.
3. What causes the P1603 code to appear in a Mazda?
The most common causes include a malfunctioning key fob, a damaged immobilizer system, wiring issues, or a faulty Engine Control Module (ECM).
4. Can a dead key fob battery trigger the P1603 code?
Yes, a dead or weak key fob battery can cause the immobilizer system to fail to recognize the key, triggering the P1603 code.
5. How can I fix the P1603 code on my Mazda?
Solutions include reprogramming the key, replacing the key fob battery, inspecting immobilizer wiring, or, in severe cases, replacing the ECM.
6. Is the P1603 code specific to Mazda vehicles?
No, P1603 can appear in other makes and models, but its definition and troubleshooting steps may differ depending on the manufacturer.
7. Can a locksmith reprogram a key to fix the P1603 code?
Yes, a professional locksmith or dealership can reprogram the key and immobilizer system to resolve the issue.
8. Does the P1603 code mean the ECM is faulty?
Not necessarily. While a faulty ECM is a possible cause, the issue is more commonly related to the key, immobilizer, or wiring.
9. Can disconnecting the battery clear the P1603 code on a Mazda?
Disconnecting the battery might temporarily clear the code, but the underlying issue will persist and may cause the code to return.
10. Is it safe to drive with the P1603 code active?
No, since the P1603 code often prevents the engine from starting, the vehicle will likely be inoperable until the issue is resolved.
Discuss the causes and fixes for P1603 Mazda OBDII Code
Code P1603 Mazda comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
