DTC 11

DTC 11:Transponder Communication System or Radio Interference of Encrypted Code

Ignition Key Ring Antenna Circuit Part 1:

Ignition Key Ring Antenna Circuit Part 2:

CIRCUIT OPERATION
The ignition key is powered by the ignition key ring antenna, and sends an encrypted code. The ignition key ring antenna receives the encrypted code, and determines whether the ignition key is a registered key or not.

DTC SET CONDITION
- DTC 11 may be output if other ignition keys are in the vicinity of the vehicle as it is being started.
- The transponder s encrypted code is not sent to the immobilizer-ECU immediately after the ignition switch is turned to "ON" position.

NOTE: DTC 11 is always output together with MFI system DTC P0513.

TROUBLESHOOTING HINTS
- Radio interference of encrypted code.
- Malfunction of transponder.
- Malfunction of ignition key ring antenna.
- Malfunction of immobilizer-ECU.
- Damaged wiring harness of connectors.

DIAGNOSIS PROCEDURE

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: Main Harness A

STEP 1. Check for presence of other key near the key in the ignition.

Q: Is there any other key near the key in the ignition?

YES: Move the other key well away from key being used. Retest the system.

NO: Go to Step 2.

STEP 2. Check that the engine start using the spare ignition key which encrypted code has been registered.

Q: Does the engine start using the spare ignition key for which the encrypted code has been registered?

YES: Replace the ignition key that does not work. Then register the password (secret code) and encrypted code. Retest the system.

NO: Go to Step 3.

STEP 3. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.




1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991958 to check immobilizer system diagnostic trouble codes.
4. Turn the ignition switch to "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.

Q: Which DTC is output, DTC 11 or 12?

DTC12 is output : Refer to DTC 12.
DTC11 is output : Go to Step 4.

STEP 4. Check the ignition key ring antenna by backprobing.




1. Disconnect the key reminder switch connector C-304.




2. Measure the resistance value between terminal number 3 and terminal number 7 by backprobing.
- The measured value should be 2 Ohm or less.

Q: Is the check result normal?

YES: Go to Step 5.

NO: Replace the ignition key ring antenna. Retest the system.







STEP 5. Check Immobilizer-ECU connector C-113 and key reminder switch connector C-304 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are immobilizer-ECU connector C-113 and key reminder switch connector C-304 in good condition?

YES: Go to Step 6.

NO: Repair or replace the damage component(s). Confirm that scan tool MB991958 communicates normally.







STEP 6. Check the harness wires between immobilizer-ECU connector C-113 (terminal 7 and 8) and key reminder switch connector C-304 (terminal 3 and 7).

Q: Are the harness wires between immobilizer-ECU connector C-113 (terminal 7 and 8) and key reminder switch connector C-304 (terminal 3 and 7) in good condition?

YES: Replace the immobilizer-ECU and then register the password (secret code) and encrypted code. Retest the system.

NO: Repair or replace the damaged component(s). Confirm that scan tool MB991958 communicates normally.