DTC 11

Ignition Key Ring Antenna Circuit:

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
- If the engine is started while several ignition keys are in the vicinity, interference between the different keys may occur, which will cause this code to be generated.
- The encrypted code of the transponder 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 P1610.

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

DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991502: Scan Tool (MUT-II)

STEP 1. Is there any other key near the key in the ignition?
If yes, move the other key well away from key being used. Confirm that diagnostic trouble code 11 is not output.
If no, go to Step 2.

STEP 2. Does the engine start using the spare ignition key which encrypted code has been registered?
If yes, replace the ignition key that does not work. Then register the password (secret code) and encrypted code.
Confirm that diagnostic trouble code 11 is not output.
If no, go to Step 3.

STEP 3. Re-check the DTC.
If DTC 12 output, refer to DTC 12.
If DTC 11 output, go to Step 4.




STEP 4. Check the ignition key ring antenna.
Disconnect the key reminder switch (ignition key ring antenna) connector C-88 and check the resistance on the harness side connector between terminal number 3 and terminal number 7.
- Should be less than 2 Ohms.
If open circuit, replace it.
Confirm that diagnostic trouble code 11 is not output.
If less than 2 Ohms, go to Step 5.







STEP 5. Check immobilizer-ECU connector C-79 and key reminder switch (ignition key ring antenna) connector C-88 for damage.
If immobilizer-ECU connector C-79 and key reminder switch (ignition key ring antenna) connector C-88 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Confirm that diagnostic trouble code 11 is not output.
If these connectors are in good condition, go to Step 6.







STEP 6. Check the harness wires between immobilizer-ECU connector C-79 and key reminder switch (ignition key ring antenna) connector C-88.
If the harness wires between immobilizer-ECU connector C-79 and key reminder switch (ignition key ring antenna) connector C-88 are damaged, repair them.
Confirm that diagnostic trouble code 11 is not output.
If the harness wires are in good condition, replace the immobilizer-ECU. Then register the password (secret code) and encrypted code.
Confirm that diagnostic trouble code 11 is not output.