| Diagnosis and Testing Refer to Wiring Diagrams Section 419-01B, for schematic and connector information. Principles of Operation Passive Anti-Theft System (PATS) The PATS uses radio frequency identification technology and a unique encryption code which matches the powertrain control module (PCM) to the anti-theft alarm module to deter a drive away theft. Passive means that it does not require any activity from the user. The PATS uses a specially encoded ignition key. Each encoded key contains a permanently installed electronic device called a transponder. Each transponder contains a unique electronic rolling identification code, this code can be any one out of millions of combinations. A maximum of eight ignition keys can be programmed to a vehicle with a maximum of four with remote control. Each encoded key must be programmed into the vehicles PCM using WDS before it can be used to start the engine. There are special diagnostic repair procedures outlined in this manual that must be carried out if a new encoded key needs to be installed. Inspection and Verification - Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Mechanical | Electrical | - Ignition lock cylinder
- PATS key
- Use of an unprogrammed key
- Use of an unprogrammed PATS key
- More than one PATS key on key chain
| - Fuse(s)
- Bulb(s)
- Wiring harness
- Electrical connector(s)
- Switch(es)
- Vehicle battery
- PATS transceiver
- PCM
- Anti-theft alarm and double locking module
| - If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the concern is not visually evident, verify the symptom and refer to WDS to diagnose the system.
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