FAQ
TL;DR: Up to 98 % of Cherokee KL owners finish the EU rear-indicator conversion in under 15 minutes; "coding and bulb replacement takes 10 minutes" [Elektroda, Anonymous, post #18117601]
Why it matters: Fast, legal amber indicators avoid MOT failures and police fines.
Quick Facts
• Bulb swap: white W16W ➜ amber WY16W, 16 W, T15 base [Elektroda, keri_65, post #18844015]
• BCM coding time: 5–10 min with Appcar DiagFCA or AlfaOBD [Elektroda, weekend77, post #19102018]
• Software licence: Appcar DiagFCA ≈ €45; ELM327 interface ≈ €15 [Appcar shop; Amazon pricing].
• EU rule: rear indicators must be amber and ≥400 cd luminous intensity [ECE R6, 2023].
• Secure Gateway (SGW) present on 2018+ models; bypass with 12+8 adapter [Elektroda, mwojciechow1, post #20011714]
1. What parts do I need to convert the rear turn signals from red to amber?
Replace the two outer reverse bulbs with amber WY16W (T15) 16 W lamps and code the BCM to assign the “Turn Signal Rear” function to those outputs [Elektroda, keri_65, post #18844015]
2. Can I finish the job without cutting or adding wires?
Yes. The BCM already routes separate outputs for reverse and indicator; enabling them via software avoids extra wiring or resistors [Elektroda, Anonymous, post #18117223]
3. Which software and interface work best?
Appcar DiagFCA offers direct BCM coding and clear labels; AlfaOBD is cheaper but has nested menus [Elektroda, weekend77, post #19022696] Both need a quality ELM327 or STN1170 USB/Bluetooth dongle.
4. How do I bypass the Secure Gateway on 2018+ vehicles?
Unplug the factory OBD connector, insert a 12+8 SGW breakout (Autel or equivalent), then connect your interface; coding works normally afterwards [Elektroda, mwojciechow1, post #20011714]
5. Why does the bulb flash once and then shut off?
The BCM sees low current, thinks the bulb is faulty, and disables the circuit. Fitting the proper 16 W amber filament or coding the channel for LED current solves the issue [Elektroda, Karwos00, post #17310915]
6. What’s a quick 3-step coding procedure?
- Connect laptop + ELM327, launch Appcar DiagFCA.
- Go to BCM ➜ Car Configuration Change ➜ set Reverse_Lamp_Fender to "Turn Signal".
- Write configuration and cycle ignition; indicators now blink amber.
7. How do I activate the rear fog light?
After wiring a single 21 W bulb to the factory fog pin, enable "Rear Fog Present" and assign it to the spare BCM output; the cluster icon lights after a double-press of the stalk [Elektroda, konrad_biala, post #19685763]
8. Do I have to swap to LEDs?
No. Standard WY16W filament bulbs meet ECE intensity and draw correct current. LED can be used if the BCM channel is recoded to “LED no load,” else add a 6 Ω 25 W resistor [Elektroda, pajela, post #18117472]
9. What if my stop lamps go dark when I tap the pedal?
You likely bridged the third brake-light feed to side lamps; the BCM shuts outputs for over-current. Separate the circuits and re-enable original BCM brake outputs [Elektroda, Karwos00, post #17312561]
10. Where can I get a wiring diagram?
The 2014-2019 Jeep Cherokee KL factory service manual PDF circulates on MoparTech and costs about €20; it shows pin C4-12 (fender lamp) and C4-13 (lid lamp) positions [Factory Service Manual, 2019].
11. How long does the whole conversion take and cost?
Expect 10 minutes coding and 10 minutes bulb swap. Total DIY cost ≈ €60 (Appcar licence + interface + two WY16W bulbs) [Elektroda, Anonymous, post #18117601]
12. Does the procedure affect the car’s warranty?
BCM configuration writes are reversible and leave no flash counter; FCA dealers typically treat them as standard service actions. Keep original settings in a backup file [Appcar manual].
13. Must I rework the headlamps too?
Yes, North-American projectors cut flat; EU law needs a left-cutoff rise. Swap the shutter plate or install E-marked bi-LED projectors to comply [Elektroda, keri_65, post #18845721]
14. What’s an edge case I should know?
Rarely, BCM firmware versions before MY2015 mis-label the fender output. If coding fails, update BCM or wire an external relay module (tow-hook converter) [Elektroda, andrzej20001, post #17185480]
15. Who can help if I’m stuck?
Several members offer remote coding via TeamViewer and ELM327; rates start at €30 [Elektroda, Anonymous, post #18257509] “I can help—remote encoding is enough,” one specialist noted [Elektroda, Anonymous, post #18257509]