Intermittents and Poor Connections

The most likely causes of intermittent no start no crank complaints due to the PASS-Key II SYSTEM are either an incorrect resistance measurement of the Ignition Key or an intermittent relay.

Incorrect resistance measurements checks:

^ If one key works and not the other, clean or replace the faulty key.

^ If condition is present with all keys, indications are that the lock cylinder is dirty/defective or there is a fault in the key resistance circuit wiring, connections or contacts.

^ A method for checking the key resistance circuit with an ohmmeter is as follows:

1. Use the J 39200 DVM to measure resistance across key contacts while removed from vehicle.

2. Disconnect the Theft Deterrent Module, insert key in Ignition. With the J 39200 set to "MIN MAX", measure resistance across terminals "B8" and "B7" of the Theft Deterrent Module Harness Connector. Listen for an audible tone from the DVM. This would indicate a fluctuating resistance, while manipulating the harness and rotating the Steering Wheel from side to side. If the resistance fluctuates, check the wiring and wiring connections to the lock cylinder for an intermittent (Ex: poor connection or broken wire inside the insulation). If the resistance is not within 5 ohms of the resistance measured on the key when it was removed from the vehicle, check for a dirty or defective lock cylinder.

3. Rotate key throughout ail positions and monitor for a resistance change. This would indicate a change of over 5 ohms indicating a problem with the lock cylinder or key contacts.

Intermittent relay checks:

^ If the "SECURITY" Indicator comes on for 5 seconds and then goes off, the relay is most likely the problem. Check connections to relay, if OK, install a new relay.

^ If the "SECURITY" Indicator remains "ON" past the 5 second bulb check when the vehicle will not crank, the relay is not the problem.

^ If it is necessary to turn the key to crank several times before the Engine will crank, the relay is probably intermittent. Check connections to relay, if OK, install a new relay

^ If the vehicle cannot be started immediately after a fault, the relay is not the problem.

Some other areas to check include the following:

^ Check that the connector to the Theft Deterrent Module is tight and terminals are clean.

^ Check for History Diagnostic Trouble Code 46 in PCM, intermittent fuel enable CKT 229. See Computers and Control Systems. Testing and Inspection

^ Check power and ground to the module while manipulating the harness.

^ During an Ignition Cycle the "SECURITY" Indicator will illuminate and remain "ON" while a problem is detected in the key resistance circuits (for at least 1 minute) and will turn "OFF" if the fault goes away.

^ Lightly tapping the Theft Deterrent Module will determine if the module is intermittent. Intermittents are typically not the Theft Deterrent Module.

^ Thermal cycle Theft Deterrent Relay and Theft Deterrent Module and reinstall in vehicle to induce fault.

Important:
^ Perform the On-Board Diagnostic System Check described in Computers and Control Systems to be certain no trouble codes are stored in PCM memory which may lead to misdiagnosis, specifically Code 46, indicating a problem in the PASS-Key II Fuel Enable circuit. Testing and Inspection