Pinpoint Test D: DTC B1602 - Pats Received Invalid Format Of Key-Code From Ignition Key Transponder

WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Large metallic objects, electronic devices on the key ring that can be used to purchase gasoline or similar items, or a second key on the same key ring as the PATS key may cause a vehicle starting concern and record DTC under certain conditions. If a fault cannot be identified, examine the customer key ring for such objects or devices. If present, inform the customer that they need to keep these objects from touching the PATS key while starting the engine. These objects and devices cannot damage the PATS key, but can cause a momentary concern if they are too close to the key during engine start. If a concern occurs, turn the ignition off and restart the engine with all other objects on the key ring held away from the ignition key. Check to make sure the PATS key used by the customer is an approved Ford PATS key. (PATS keys from Ford, Rotunda, Strattec, or HUF are approved Ford PATS keys.)

NOTE: Only 8 PATS keys can be programmed into the PCM using the Key Programming Using Diagnostic Equipment procedure unless the unlimited key mode is active. If the N_KEYCODE (number of keys programmed) PID reads more than 2, the concern may be the PATS key being used is an unprogrammed key. Verify this by also viewing the MASTERKEY (master key) PID. It must read PRESNT for the key to be valid.

D1 RETRIEVE THE DTCs
- If only one key is available, cut a new key and program the keys. Refer to Key Programming Using Diagnostic Equipment .
- Key in ON position.
- Clear the PCM DTCs.
- Key in OFF position.
- Key in ON position.
- Retrieve the PCM DTCs.
- Is DTC B1602 retrieved for one or both PATS keys?
1. YES : If DTC B1602 is retrieved for one key, REPLACE that key and PROGRAM the new key. REFER to Spare Key Programming - Using Diagnostic Equipment . CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test.
  If DTC B1602 is retrieved for both PATS keys, go to D2 .
2. NO : The system is OK. CHECK all the customer PATS keys by attempting to start the vehicle with each key to VERIFY all the other PATS keys are programmed. The concern may have been caused by interference from another object.
D2 INSTALL A NEW PATS TRANSCEIVER
NOTE: Replacement of the PATS transceiver does not require the PATS keys to be programmed into the PCM again.
- Key in OFF position.
- Install a new PATS transceiver. Refer to Passive Anti-Theft System (PATS) Transceiver .
- Key in ON position.
- Clear the PCM DTCs.
- Key in OFF position.
- Key in ON position.
- Retrieve the PCM DTCs.
- Are any PATS DTCs retrieved?
1. YES : Go to D3.
2. NO : The system is OK. CHECK all the customer PATS keys by attempting to start the vehicle with each key to VERIFY all the other PATS keys are programmed.
D3 CHECK FOR CORRECT PCM OPERATION
NOTE: When a new PCM is installed, the PATS keys must be programmed into the PCM.
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . PROGRAM the PATS keys into the PCM. REFER to Key Programming Using Diagnostic Equipment . REPEAT the self-test.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. CYCLE the ignition. REPEAT the self-test.