B1602
Moderate Severity (Level 3)PATS Received Invalid Format Of Key-Code From Ignition Key Transponder
B1602 usually means pATS Received Invalid Format Of Key-Code From Ignition Key Transponder.
Can you still drive with B1602?
⚠️Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
Typical repair cost: $100 – $800
Severity Level 3 — Moderate
This code indicates a moderate issue that may affect vehicle performance and fuel economy. Continued driving is possible in most cases, but prompt diagnosis and repair are recommended to prevent further damage.
Common Symptoms
- Engine cranks but won't start — immobilizer preventing start
- Alarm going off randomly or not arming
- Check Engine Light illuminated
- Diagnostic trouble code (DTC) stored in module memory
Possible Causes
- Faulty immobilizer antenna — most common cause, test before replacing
- Damaged or corroded wiring/connector in the key/immobilizer system circuit
- Blown fuse or faulty relay for the key/immobilizer system
- Poor ground connection — check and clean all related ground points
- Control module fault — rare but possible, only consider after ruling out simpler causes
Common Fixes
- Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($4-83 at shop, free at auto parts store for basic scan)
- Visually inspect the key/immobilizer system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $56 diagnostic fee at shop)
- If the engine cranks but won't start, check the security/immobilizer light — if flashing, try a different key. Key programming may be needed ($141-776 at dealer or locksmith)
- Replace immobilizer antenna if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($100-800)
- Check and replace any blown fuses in the key/immobilizer system fuse circuit — if fuse blows again, there's still a short that needs to be found ($2-18 for fuses)
Estimated Repair Cost
These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.
Frequently Asked Questions
What does B1602 mean?
B1602 stands for "PATS Received Invalid Format Of Key-Code From Ignition Key Transponder". B1602 usually means pATS Received Invalid Format Of Key-Code From Ignition Key Transponder.
Can you drive with B1602?
Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
How much does it cost to fix B1602?
Repair costs for B1602 typically range from $100 to $800, depending on your vehicle make, model, and local labor rates. Common fixes include: Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($4-83 at shop, free at auto parts store for basic scan); Visually inspect the key/immobilizer system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $56 diagnostic fee at shop); If the engine cranks but won't start, check the security/immobilizer light — if flashing, try a different key. Key programming may be needed ($141-776 at dealer or locksmith).
Will B1602 clear itself?
Explore Repair Costs
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