Fix P0513: Mechanic’s solutions that WORKED

The P0513: Incorrect Immobilizer Key code suggests there’s a mismatch or problem with the vehicle’s immobilizer key, which is crucial for starting the engine. The immobilizer system is designed to prevent the unauthorized starting of the vehicle, and this code indicates that the system does not recognize the key being used, potentially due to a faulty key, issues within the immobilizer system, or problems in the PCM.

P0513 quick overview

Meaning	P0513: Incorrect Immobilizer Key
Is it serious?	This code can be serious as it may prevent the vehicle from starting or cause it to stall unexpectedly.
Possible causes	– Faulty or incorrect key – Issues with the immobilizer system – Problems with the vehicle’s PCM (Powertrain Control Module) – Faulty wiring or connections in the immobilizer circuit
How to diagnose?	Inspect the Key: Check if the key is damaged or incorrect for the vehicle. Test with a Spare Key: If available, try starting the vehicle with a spare key to rule out a key-specific issue. Scan for Additional Codes: Use a diagnostic tool to check for other related codes that might provide more clues. Check Wiring and Connections: Inspect the immobilizer circuit for any damaged wiring or poor connections. Evaluate the PCM: Test the PCM for any faults or consider reprogramming if necessary. Consult Technical Service Bulletins (TSBs): Check for any manufacturer’s bulletins that might relate to this issue for your specific vehicle model.

How to fix P0513 – learn from mechanics

I looked into P0513 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Mitsubishi

Vehicle Information: 2007 Mitsubishi Galant ES 2.4L

Issue + Repair History: Car was hauled in as a no start, cranking fine but not starting. It had a code P0513 (immobilizer unit ECM communication error). The issue began after the customer turned off the car and went into work. Attempts were made to clear codes and try a different key.

Other OBD2 Codes + Test Results: P0513 – Immobilizer unit ECM communication error.

Suggestions to Fix Issue:

• Try using a different key for the vehicle.
• Perform an ignition key learning procedure.
• Consider the possibility of a faulty key that needs replacement.

Final Fix: The issue was due to a remote start system. A key used in the system’s pass box had moved out of position and wasn’t being read. After repositioning and securing the key, the car started, and the code was resolved.

Case #2: Chrysler

Vehicle Information: 2004 Chrysler Pacifica 3.5L

Issue + Repair History:

• Initially, the car had a no cranking, no start issue, with a message in the instrument cluster: P0513 service immobilizer.
• No communication with PCM, but could communicate with BCM and SKIM.
• Power, grounds, data links, and harness checked with no problems found.
• PCM sent to CAR COMPUTER EXCHANGE, returned with a report of being in theft lock, disabling injectors.
• After PCM return, the car still displayed P0513 service immobilizer and additional codes: SKIM for PCM failure, Serial link external failure, P0645 A/C clutch relay, P0627 Fuel pump relay, and P0685 ASD relay.
• Temperature sensor readings were fluctuating.
• Replaced PCM for intermittent stall and no start, no codes in any system before PCM replacement. PCM was a remanufactured unit from CAR COMPUTER EXCHANGE.

Other OBD2 Codes + Test Results:

• P0513: Service immobilizer
• SKIM: PCM failure
• SKIM: Serial link external failure
• P0685: ASD relay circuit
• P0627: Fuel pump relay
• P0645: A/C clutch relay

Suggestions to Fix Issue:

• Rechecking grounds, especially those on the frame in front.
• Checking 5-volt reference voltage and potential issues with the crank sensor.
• Examining the main ground at the transmission for issues like cable pulling out of the terminal.
• Loading all powers and grounds at the PCM to confirm integrity.
• Resetting all computers to allow them to communicate effectively.
• Consider getting all keys from the owner and having the dealer re-pair all the keys to the vehicle.

Final Fix: The issue was resolved with a dealer PCM after trying three different remanufactured PCMs, each presenting different problems.

Case #3: Jeep

Vehicle Information: 2013 Jeep Wrangler Sport 3.6L

Issue + Repair History:

• Experienced a no crank/start issue.
• The problem was temporarily resolved by removing fuse M13 for the Wireless Control Module (WCM) and waiting 30 minutes before reinstalling it.

Other OBD2 Codes + Test Results:

• P0513: Invalid SKIM key

Suggestions to Fix Issue:

• A cold boot (removing and reinstalling the fuse) can temporarily fix the issue.
• There is an updated program/software update available for the WCM which might provide a permanent solution.
• TSB (Technical Service Bulletin) 08-068-14 is applicable for a WCM software update.

Final Fix: System reset by removing the fuse as a temporary solution. Informed the customer that if the issue recurs, a software update for the WCM will be needed.

Case #4: Volkswagen

Vehicle Information: 2008 Volkswagen Jetta SEL 2.5L

Issue + Repair History:

• Originally brought in due to the key being stuck in the run position.
• After applying penetrating oil, the key issue was temporarily resolved.
• Ordered and replaced the ignition lock cylinder and lock cylinder housing.
• After repair, the car started but immediately died, displaying trouble codes P0513 and manufacturer code 01299 for incorrect immobilizer key.

Other OBD2 Codes + Test Results:

• P0513: Incorrect immobilizer key
• 01299: Manufacturer-specific code related to the immobilizer

Suggestions to Fix Issue:

• Suggestion to leave the key in the run position for up to 40 minutes with a battery charger attached to fully charge the battery.
• Check the immobilizer system for any issues related to the new installation.

Final Fix:

• Followed the suggestion of leaving the key in the run position for 40 minutes with a battery charger, after which the car started and ran normally.
• No programming was required, but this step helped the car’s system recognize the key after the lock cylinder replacement.

Case #5: Buick

Vehicle Information: 2012 Buick Enclave 3.6L

Issue + Repair History:

• Intermittent stall and no start after hot soak, displaying Theft Deterrent message.
• Engine stalls, cranks but does not start, then restarts fine after some time.
• Replaced underhood fuse box but did not fix the issue.
• Focused on Powertrain Relay circuit, but the vehicle did not stall during testing.
• Control ground for relay supplied by PCM at pin 72 of connector X1 measured at 0.680 mV.

Other OBD2 Codes + Test Results:

• P0513: Theft Deterrent Key Incorrect
• Checked computer grounds – results were good.

Suggestions to Fix Issue:

• Check the theft code as it could be causing the start and stall problem.
• Test the power and ground circuits at the ECM connectors.
• Check the ignition tumbler and try a second key if available.
• Inspect grounds at various points (G110, G112, G115).
• Monitor power modes in BCM data to ensure the ignition switch is functioning correctly.
• Check all systems for codes, particularly U0100 loss of communication with ECM.
• Conduct voltage drop tests on the ECM.

Final Fix:

• Replaced ECM, reprogrammed, and road-tested the vehicle.
• After extensive testing, the vehicle was sent home and the issue was resolved.

Advice	Description of Diagnostic Step
Check for aftermarket parts	Verify if any aftermarket components like PCMs or sensors were used, as they can cause issues.
Inspect and test grounds	Ensure all ground connections are secure and intact, especially those related to the PCM and related systems.
Check power and ground circuits at ECM	Perform voltage drop tests on the ECM’s power and ground circuits to rule out electrical issues.
Verify key and immobilizer system	Test the key and immobilizer system for issues, possibly trying an alternate key if available.
Replace with OEM parts if necessary	Consider using original equipment manufacturer (OEM) parts, particularly for crucial components like the PCM.
Conduct a thorough systems check	Scan all vehicle systems for codes and irregularities, as they can provide clues to the root cause.
Examine related connectors and wiring	Inspect connectors and wiring, particularly those related to the ECM and immobilizer, for damage or corrosion.
Update or reprogram PCM if required	Check for software updates for the PCM and reprogram if necessary.