DTC Diagnostic Strategy

If the module DTC list results in a large number of DTCs, diagnose all module hard faults first (C102D, C1B00, C200B, C200C, C200D, U2011, and U3000) before diagnosing any network faults (lost communication or invalid data). If voltage concern DTCs are present, diagnose those after any module hard faults and before any network faults.

1. IV1: VISUAL INSPECTION 
   NOTE: The ignition must be off, and remain off, when disconnecting PSCM electrical connectors. Failure to follow this direction may lead to DTCs being set in the PSCM which cannot be cleared and result in the need to install a new EPAS steering gear.
   NOTE: If equipped, the Lane Keeping System (LKS) can interfere with accurate EPAS diagnostics. Disable the Lane Keeping System (LKS) before test driving the vehicle to diagnose EPAS concerns. For information on disabling the Lane Keeping System (LKS), refer to the Owner's Literature.
   NOTE: When inspecting the bellows boots make sure to use a strong light source and an inspection mirror.
   • Verify the customer concern.
   • Visually inspect the EPAS system for obvious signs of electrical or mechanical damage, including any signs of leakage.

     VISUAL INSPECTION CHART - EDGE, MKX 

     Mechanical	Electrical
     Tire pressure	High-current BJB fuse 6 (80A)
     Tire condition and wear	BJB fuse 19 (10A)
     Binding or misaligned steering column	Wiring, terminals or connectors
     Loose steering column shaft bolts
     Steering column shaft couplings and U-joints
     Steering column shaft dash boot
     Steering gear
     Steering gear bellows boots
     Inner tie rod ends
     Outer tie rod ends

   • Is an obvious cause for an observed or reported concern found? 

   Yes	No
   Go to  IV2.	For signs of leakage, Go to PINPOINT TEST K . For all others, Go to PINPOINT TEST KC .

2. IV2: DAMAGED STEERING GEAR BELLOWS BOOT 
   • Was a damaged steering gear bellows boot identified during the visual inspection? 

   Yes	No
   Go to  IV3.	For signs of leakage, Go to PINPOINT TEST K . For all others, REPAIR the concern identified during the visual inspection.

3. IV3: ISOLATE THE DAMAGED BELLOWS BOOT(S) AS THE CONCERN 
   • Review the repair order and verify there are no customer concerns (such as a message on the message center or NVH steering system concern) in addition to the damaged bellows boot(s).
   • Are any other customer concerns present? 

   Yes	No
   Make note of the damaged bellows boot(s). Go to Known Concerns  After diagnosis is complete, if a new EPAS gear or bellows boot has not been installed, Go to PINPOINT TEST K .	Go to PINPOINT TEST K .