🚨 Diagnostic Profile
Vehicle Make: Dodge
Fault Description: No Auto Shutdown (ASD) Relay Output Voltage At PCM
This fault indicates the Powertrain Control Module (PCM) is not detecting the expected output voltage from the ASD relay control circuit. The ASD relay supplies battery power to the ignition coils, fuel injectors, and O2 sensor heaters, so a fault here can cause a no-start, stall, or crank-no-run condition. Verify the specific model, year, and engine before testing, since circuit layouts, PDC fuse/relay positions, and PCM connector pinouts vary significantly across Dodge platforms (e.g., Ram truck PDC layouts differ from Charger/Challenger/Durango layouts).
🚨 Repair Difficulty Tier
Tier: [Intermediate]
This repair requires a digital multimeter, familiarity with relay circuit testing, and the ability to read a wiring diagram for the specific vehicle. Access to the Power Distribution Center (PDC) and PCM connectors may require removing trim or panels. Diagnosis should be performed by a technician comfortable with electrical troubleshooting.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
- Check battery state of charge (minimum 12.4V resting, confirm proper charging output at idle) and clean/tighten battery terminals and main engine-to-chassis and chassis-to-block grounds.
- Inspect the ASD relay fuse and the associated circuit fuse in the Power Distribution Center (PDC), typically mounted in the engine compartment near the battery on most Dodge platforms, for corrosion, looseness, or an open (blown) fuse element.
- Visually inspect the ASD relay and its socket in the PDC for burn marks, melted terminals, or corrosion at the relay cavity contacts.
- Inspect the wiring harness between the PDC, ASD relay, and PCM for chafing, pinched wires, rodent damage, or water intrusion, paying close attention to areas near the firewall grommet and engine mounts.
- Inspect the PCM connectors for bent, pushed-out, or corroded terminals and verify full connector seating and locking tab engagement.
- Check PCM ground straps and engine-to-chassis grounds for corrosion, looseness, or missing fasteners.
- Retrieve and record any related diagnostic trouble codes and freeze frame data using a capable scan tool before clearing codes.
Step 2: Diagnostic Verification
- Confirm battery voltage is present at the ASD relay battery feed terminal with the key on; this circuit should read very close to actual battery voltage (typically 12-14V with engine running) with minimal voltage drop from the battery positive terminal.
- Test the ASD relay coil control circuit from the PCM using a digital multimeter. With the ignition on, the PCM should ground or energize the relay coil control circuit momentarily (and continuously once cranking/running is detected); compare observed switching behavior to the service information logic for the specific engine control strategy rather than assuming a fixed voltage value.
- Verify ASD relay coil resistance and continuity using an ohmmeter with the relay removed from the circuit; automotive relay coils commonly measure in the 60-100 ohm range, but confirm against the OEM service manual specification for the exact relay part number installed.
- Check the ASD relay output circuit (battery feed side) for voltage at the ignition coil, fuel injector, and O2 sensor heater connectors per the specific wiring diagram for the vehicle’s engine and model year; do not assume a universal pin number, as this varies by PCM connector design.
- Perform a voltage drop test on the relay feed and output circuits under load (cranking or simulated load); a healthy circuit should show less than approximately 0.3-0.5V drop across any single connection or splice.
- Check PCM ground circuits for voltage drop under load; a good ground circuit should measure less than approximately 0.1-0.2V drop between the PCM ground pin and true battery negative.
- If the relay and wiring test good, verify PCM output driver function using a scan tool’s bi-directional controls (where supported) to command the ASD relay on/off and confirm the PCM registers the correct feedback voltage state before condemning the PCM.
Step 3: Resolution & Reset Process
- Replace the failed component, such as the ASD relay, fuse, damaged wiring section, or corroded connector terminal, using OEM Mopar or equivalent-quality parts matched to the vehicle’s VIN and build specification.
- Repair any wiring with proper soldered or crimped splices and adhesive-lined heat-shrink insulation rated for the underhood environment. Do not use unapproved tap splices or electrical tape in the engine bay.
- Clear all diagnostic trouble codes using a scan tool and perform a PCM readiness/monitor check if applicable.
- Perform a key-on/engine-off check and confirm the ASD relay audibly energizes (listen/feel for the click) and that the PCM registers the correct ASD relay output voltage state via scan tool data PID.
- Start the engine and verify normal operation, confirm no stored or pending codes return, and verify proper charging system voltage (typically 13.5-14.7V at idle with accessories off).
- Road test the vehicle through multiple key cycles and drive conditions, then recheck for codes after the drive cycle is completed to confirm the repair is stable.
📦 Parts, Labor, and Budget Estimates
Required Components/Software:
- ASD relay: OEM Mopar relay matched to VIN (verify exact part number via dealer parts lookup or VIN-specific parts catalog)
- Fuse(s) as required: OEM-rated ampere fuse matching PDC fuse map for the specific model/year
- Wiring repair materials: automotive-grade crimp connectors, adhesive-lined heat-shrink tubing, and OEM-gauge-matched wire
- Scan tool capable of bi-directional PCM controls and live data streaming (e.g., factory-level Dodge/Chrysler diagnostic software or an equivalent professional-grade scan tool)
Average Component Price:
- ASD relay: approximately $15 – $45
- Fuse(s): approximately $2 – $10
- Wiring and connector repair materials: approximately $10 – $50 depending on harness section repaired
- PCM (only if confirmed faulty, including programming): approximately $400 – $1,200 parts and programming combined, varying significantly by model and year
Estimated Labor Hours:
- Diagnostic time: approximately 0.5 – 1.5 hours
- Component replacement time (relay/fuse): approximately 0.2 – 0.5 hours
- Wiring repair time, if required: approximately 0.5 – 2.0 hours depending on harness accessibility
- PCM replacement and programming time, if required: approximately 1.0 – 2.5 hours
- Verification and road test time: approximately 0.3 – 0.5 hours