🚨 Diagnostic Profile
Vehicle Make: Chrysler
Fault Description: Electronic Throttle Module Low Volts Communication Disable
Short description: The powertrain control module has disabled electronic throttle communication because the throttle control module is reporting or receiving voltage below its operating range. Confirm the exact DTC and freeze-frame data with a scan tool before proceeding. Specific module and connector references: the electronic throttle body is mounted directly on the intake manifold, with its main harness connector on the body itself; the PCM is typically located at the front of the engine bay near the battery or inner fender, and the underhood power distribution center (fuse/relay box) is adjacent to the battery.
🚨 Repair Difficulty Tier
Tier: [Intermediate]
Justification: Diagnosis requires a digital multimeter, scan tool access, and understanding of voltage drop testing on supply and ground circuits. Repair often involves battery and charging system checks, connector inspection, and possible module reprogramming or reset, which exceed basic DIY scope.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
- Verify battery state of charge (should read approximately 12.4–12.6V at rest) and load test the battery; confirm terminals are clean, tight, and free of corrosion.
- Check the charging system output at the battery with the engine running; alternator output should typically fall within 13.5–14.7V under normal load, per standard charging system specifications.
- Inspect the throttle body harness connector and PCM connectors for corrosion, pin push-out, bent terminals, or moisture intrusion at the throttle body mounted on the intake manifold.
- Inspect main battery positive and negative cables, along with engine-to-chassis and body-to-chassis ground straps, for resistance, corrosion, or physical damage.
- Check related fuses and relays in the underhood power distribution center, referencing the fuse box lid diagram for throttle actuator control (TAC) and PCM-related circuits.
- Record all active and stored DTCs, freeze-frame data, and battery voltage at time of fault using a capable OBD-II scan tool.
Step 2: Diagnostic Verification
- Perform a voltage drop test on the throttle module supply circuit under load; total voltage drop across the full circuit (power and ground combined) should not exceed approximately 0.1–0.3V per standard industry voltage drop testing guidelines.
- Perform a voltage drop test on the module ground circuit independently, checking from the module ground pin back to a known good chassis/engine ground point.
- Verify module reference and supply voltage at the throttle body connector using a digital multimeter against a known good ground; confirm it falls within the expected reference voltage range (typically 5V logic supply or battery voltage on the main power feed, depending on the circuit being tested).
- Check communication network status (CAN bus) using the scan tool’s module status screen and confirm whether the fault is isolated to the throttle control circuit or caused by another module pulling the bus voltage down or causing a communication fault.
- Inspect the module and throttle body assembly for internal faults (e.g., sticking plate, internal resistance out of spec) only after all external wiring, voltage, and ground tests pass clean.
Step 3: Resolution & Reset Process
- Repair or replace the faulty wiring, connector, ground strap, fuse, or charging component identified in Steps 1 and 2 using OEM-spec connectors and proper crimp/solder, heat-shrink termination methods.
- Replace the electronic throttle body/control module as an assembly only if testing confirms an internal fault; this is typically serviced as a complete throttle body unit rather than an individually replaceable internal module.
- Reconnect the battery and perform the required throttle body relearn/minimum airflow idle adaptation procedure using a capable scan tool, per the manufacturer’s service information for the specific engine and model year.
- Clear all stored DTCs and perform a road test covering varied throttle inputs, idle conditions, and a full drive cycle to confirm the fault does not return.
- Re-scan all modules on the vehicle network to confirm no related communication, voltage, or throttle actuator control codes remain stored.
📦 Parts, Labor, and Budget Estimates
Required Components/Software:
- Battery (if load test fails) or charging system components (alternator, serpentine belt) if indicated
- Wiring repair kit, OEM-spec connector/terminal pins, and dielectric grease if corrosion or damage is found
- Electronic throttle body assembly (complete unit with integrated TPS/motor), if internal fault confirmed
- OEM-level scan tool with bi-directional control and throttle relearn capability (e.g., dealer-level or professional aftermarket scan tool subscription)
Average Component Price:
- Battery replacement: approximately $150–$280 (parts only, group size dependent)
- Alternator replacement: approximately $250–$550 (parts only)
- Wiring repair kit, connectors, terminals, and fuses: approximately $15–$90 depending on scope of repair
- Electronic throttle body assembly: approximately $180–$450 (parts only, OEM vs. aftermarket dependent)
- Scan tool diagnostic/programming access fee (if outsourced to a dealer or specialty shop): approximately $100–$220 one-time diagnostic/programming charge
Estimated Labor Hours:
- Preliminary inspection and diagnosis (battery, charging system, visual connector inspection): 0.5–1.0 hour
- Electrical verification and voltage drop testing (supply/ground circuits, network communication check): 0.8–1.5 hours
- Component repair or replacement (wiring repair, throttle body replacement, battery/alternator swap): 0.5–2.0 hours depending on component
- Relearn, reset, and verification drive cycle: 0.3–0.6 hour
Estimated Total Diagnostic-Only Cost: approximately $90–$180 (shop diagnostic labor rate dependent, typically $110–$170/hour)
Estimated Total Repair Cost (parts and labor combined, throttle body replacement scenario): approximately $350–$750