Electrical supply and module communication
Multiple warnings can share a single root cause such as low 12-volt voltage, a weak ground, water intrusion, a fuse-box supply fault or a disrupted vehicle network. Start with battery condition, charging output, cranking voltage and a complete module scan. Compare fault timestamps and communication patterns before condemning a module. Some later models include 48-volt mild-hybrid or high-voltage components requiring special precautions.
Manufacturer-specific considerations
A no-crank fault should be separated from crank/no-start. Verify starter authorization and supply before fuel or ignition tests; on newer models check gateway wake-up and key authorization when relevant.
Repair confirmation
After repair, verify several ignition and sleep/wake cycles, charging behavior and that all affected modules communicate.
The source research addresses Range Rover Evoque applications described as 2013–2019 (Range Rover Evoque L538). The correct testing depends on the exact year, engine, drivetrain and equipment.
Symptoms an owner may notice
P2178 rich off idle and P2187 lean at idle; P2178 remained after PCV, MAF and throttle cleaning.
MIL with backup-battery DTCs U2109-09 and U2109-91.
New in-wheel TPMS sensor installed; programming/learning procedure requested.
Factory Land Rover procedure in ALLDATA did not reset oil maintenance.
Codes documented in the research include P2178, P2187, U2109-09, U2109-91. A code indicates a monitored condition and is not proof that one particular component failed.
What diagnosis involves
The available case notes describe checks such as Inspect TCU computer. The actual vehicle must be evaluated before any repair recommendation.
Findings recorded in the cases included Internal damage found. These observations may guide testing but cannot be assumed on another vehicle.
Documented causes and repair decisions
In the researched cases, identified causes included Internal damage to TCU computer/embedded backup battery. A different vehicle with the same symptoms may have a different underlying problem.
Reported successful repairs in the research included Replace and reprogram TCU computer. These are external case outcomes, not claims that Mich’s performed those specific repairs.
Some attempted repairs were ineffective or temporary, including Replace mass-airflow sensor — unsuccessful; Clean throttle body — unsuccessful. That is one reason to verify the failure before replacing components.
If your Range Rover Evoque has a similar symptom, contact Mich’s Foreign Cars in Hickory, NC at 828-324-6012. Share the model year, engine, exact warning messages and the conditions when the problem occurs.