Intermittents

IMPORTANT:
^ Additional information for detecting Electrical Intermittents can be found on page 8A-48. The most likely causes of intermittent starting or cranking 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 you have tried a key that did not work, you must wait 3 minutes for the "Tamper Mode" timer to time out before a new key can be tried.
^ 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 Body Control Module (BCM), insert key in Ignition. With the J 39200 set to "MIN MAX", measure resistance across terminals "C2" and "D7" of BCM harness connector C3. Listen for an audible tone from the DVM. This would indicate a fluctuating resistance, while manipulating tile 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 all 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 the 5 second bulb check 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 tile connector to the BCM is tight and terminals are clean.
^ Check for Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTCs). Refer to Engine Controls. Powertrain Management
^ 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 tile BCM will determine if the module is intermittent. Intermittence are typically not found in the BCM.
^ Thermal cycle Starter Relay and BCM and reinstall in vehicle to induce fault.

IMPORTANT: Perform the On-Board Diagnostic System Check described in Engine Controls to be certain no DTCs are stored in PCM memory which may lead to misdiagnosis, specifically DTCs indicating a problem in the PASS-Key-II Fuel Enable circuit.