B1702

DTC B1702: Reception Error of Transponder Data.














CIRCUIT OPERATION

The ignition key is powered by the ignition key ring antenna. The ignition key then sends an encrypted code. The key reminder switch (ignition key ring antenna) receives the encrypted code, and determines if the ignition key is registered.

DTC SET CONDITION

- DTC B1702 may be set if other ignition keys or things that interferes communication (such as magnets and equipment that generates radio waves) are in the vicinity of the ignition switch as it is being started.
- The transponder encrypted code is not sent to the ETACS-ECU immediately after the ignition switch is turned to "ON" position.

NOTE:
DTC B1702 is always output together with MFI system DTC P0513.

TROUBLESHOOTING HINTS

- Radio interference of the encrypted code
- Malfunction of the transponder
- Malfunction of the ETACS-ECU

DIAGNOSIS

Required Special Tools:

- MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827 M.U.T.-III USB Cable
- MB991910 M.U.T.-III Main Harness A

STEP 1. Check for presence of other key or things that interferes communication (such as magnets and equipment that generates radio waves) near the key in the ignition.

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

YES Move the other key or things that interferes communication (such as magnets and equipment that generates radio waves) 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 and then register the encrypted code (Refer to Procedures).
Retest the system.
NO Go to Step 3.
STEP 3. Recheck for diagnostic trouble code.





(1)
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.

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 set, DTC B1702 or B1703?

DTC B1703 is set : Refer to DTC B1703 B1703.

DTC B1702 is set : Go to Step 4.

STEP 4. Check the key reminder switch (ignition key ring antenna).

Check the key ring antenna continuity.





(1)Disconnect key reminder switch (ignition key ring antenna) connector C-310, and check at the component side.





(2)Measure the resistance value between terminal number 3 and terminal number 7.
OK: Continuity exists (2ohms or less)

Q. Is the check key reminder switch (ignition key ring antenna) in good condition?

YES Go to Step 5.

NO Replace the key reminder switch (ignition key ring antenna). Retest the system.

STEP 5. Check ETACS-ECU connector C-218 and key reminder switch (ignition key ring antenna) connector C-310 for loose, corroded or damaged terminals, or terminals pushed back in the connector.









Q. Are ETACS-ECU connector C-218 and key reminder switch (ignition key ring antenna) connector C-310 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 wiring harness between ETACS-ECU connector C-218 (terminal 57 and 58) and key reminder switch (ignition key ring antenna) connector C-310 (terminal 3 and 7).









Q. Are the wiring harness between ETACS-ECU connector C-218 (terminal 57 and 58) and key reminder switch (ignition key ring antenna) connector C-310 (terminal 3 and 7) in good condition?

YES Replace the ETACS-ECU and then register the encrypted code (Refer to Procedures).
Retest the system.

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