DTC - 11 Diagnostic Procedures

Transponder Communication System or Radio Interference of Encrypted Code

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 set.
- The encrypted code of the transponder is not sent to the immobilize-ECU immediately after the ignition switch is turned to ON position.

NOTE: DTC 11 is always set together with MFI system DTC P161O.

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

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool

STEP 1. Check that DTC I2 is set.

Q: Is DTC 12 set?

YES (DTC 12 is set): Refer to DTC 12.
DTC 11 is set: Go to Step 2.

STEP 2. Check that there is other key(s) near the key in the ignition.

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

YES: Move the other key(s) well away from key being used. Confirm that diagnostic trouble code 11 is not set.
NO: Go to Step 3.

STEP 3. Check that the engine starts using the spare ignition key which encrypted code has been registered.

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

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 set.
NO: Go to Step 4.

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




1. Measure at key reminder switch connector C-201 without disconnecting the connector.




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

Q: Is the resistance less than 2 ohms?

YES: Go to Step 5.
NO: Replace the ignition key ring antenna. Confirm that diagnostic trouble code 11 is not set.







STEP 5. Check immobilize-ECU connector C-128 and ignition key ring antenna connector C-201 for damage.

Q: Are immobilize-ECU connector C-128 end ignition key ring antenna connector C-201 in good condition?

YES: Go to Step 6.
NO: Repair or replace connector(s). Refer to Harness Connector Inspection. Confirm that diagnostic trouble code 11 is not set.







STEP 6. Check the wiring harness between immobilize ECU connector C-128 (terminals 3 and 7) and ignition key ring antenna connector C-201 (terminals 10 and 11).

Q: Is the wiring harness between immobilize-ECU connector C-128 (terminals 3 and 7) and ignition key ring antenna connector C-201 (terminals 10 and 11) in good condition?

YES: Replace the immobilize-ECU. Then register the password (secret code) and encrypted code. Confirm that diagnostic trouble code 11 is not set.
NO: Repair the wiring harness. Confirm that diagnostic trouble code 11 is not set.