🚨 Diagnostic Profile
Vehicle Make: BMW
Fault Code Description: Switching Solenoid for Air Assisted Injection Valves Bank 2 Control Circuit Signal High
This fault indicates that the control module is detecting a voltage signal higher than the expected calibrated range on the control circuit for the Bank 2 air-assisted injection solenoid. This typically points to a wiring short to voltage, a failed solenoid coil, or a faulty driver stage within the DME (Digital Motor Electronics) module.
🚨 Repair Difficulty Tier
Classification: Intermediate
This repair requires the use of a multimeter and a BMW-specific diagnostic scanning tool (such as ISTA/D) to read live solenoid circuit data and perform active tests. While the physical replacement of the solenoid is mechanically straightforward, accurately diagnosing whether the fault lies in the wiring harness, the solenoid itself, or the DME driver circuit requires intermediate electrical diagnostic knowledge. No airbag or restraint systems are involved, so it does not reach Professional Only liability tier, but accuracy in circuit testing is essential to avoid misdiagnosis.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin with a visual inspection of the Bank 2 air injection solenoid connector and wiring harness. Look for signs of chafed insulation, corrosion, or exposed wire that could be shorting to a voltage source (such as battery positive or another high-voltage circuit). Check the ground and signal wire connectors at the DME for looseness or pin damage. Inspect the solenoid body itself for physical damage, cracking, or oil contamination that may indicate internal electrical breakdown.
Step 2: Diagnostic Verification
Connect a BMW-capable scan tool (ISTA or equivalent) and pull live data for the Bank 2 solenoid control circuit. Use the multimeter to back-probe the solenoid control circuit connector and measure voltage with the key on, engine off, and again during an active test commanded through the scan tool. A reading showing battery voltage constantly present (even when the solenoid should be off) confirms a short-to-power condition. Additionally, check resistance across the solenoid coil itself—compare the reading to BMW specification (typically in the 20-40 ohm range depending on model) to rule out an internally shorted coil.
Step 3: Resolution & Reset Process
If wiring is found to be chafed or shorted, repair or replace the damaged harness section with proper BMW-spec wiring and connectors, ensuring no contact with sharp edges or heat sources. If the solenoid itself tests out of specification, replace the Bank 2 air-assisted injection solenoid valve. After repair, clear the fault codes using the scan tool, then perform a full key-cycle and road test while monitoring live data to confirm the control circuit signal returns to normal voltage range with no recurrence of the fault.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: Bank 2 air injection switching solenoid, wiring harness repair kit (if needed), BMW ISTA/D diagnostic software access
Average Component Price: $80 – $220 for the solenoid valve; $50 – $150 for harness repair materials if required
Estimated Labor Hours: 1.0 – 2.0 hours for diagnosis and solenoid replacement; add 0.5 – 1.5 hours if wiring harness repair is necessary