A stock ECU throws a vague code. MANA names the actual failed circuit and the factory pin number — and it tells you before you ever leave the driveway.
These cars are 30+ years old. The harness is aging, the connectors are corroding, and every owner knows the gremlins: the intermittent no-start, the stumble that never happens at the shop, the code that just says "sensor circuit." A stock ECU throws a vague number. MANA finds the actual broken wire and explains what happened.
Turn the key. Before the engine cranks, the ECU runs a full self-diagnostic in about two seconds and gives you a straight answer: GO / CAUTION / NO-GO, with a plain-English list of anything it found:
| Power self-test | Every internal rail, battery voltage, processor, memory and CAN checked before anything else runs |
| Harness sweep | Every sensor circuit checked for open, short, or degraded resistance; every injector and coil channel polled for open-load and shorts |
| Sensor sanity | Cold-soak plausibility snapshot — do the sensors agree with each other before you drive? |
| The verdict | "READY." Or: "CAUTION: rear O2 heater open (pin 76) — closed-loop degraded." Or: "DO NOT DRIVE: injector 3 circuit open (pin 14)." |
| What changed | New faults are diffed against your last key-on — you see what changed since yesterday, not a wall of history |
| Harness self-test | Active resistance sweep of every circuit, classified OPEN / SHORT / IN-RANGE / DEGRADED. Degraded means drifted resistance — corrosion and chafe caught before they become a no-start. Every result names the signal and the factory connector pin number, so you go straight to the wire. |
| Every output supervised | Injector and ignition drivers report open-load, short, and over-temperature per channel — an unplugged injector or a dying coil circuit is identified by cylinder, in seconds |
| Active tests | Engine off, from the laptop: click each injector, fire each coil channel, cycle the idle stepper, toggle the fuel-pump and fan relays — and the ECU confirms each one actually responded. Bench-test the whole car without starting it. |
| Codes with reasoning | Every fault stores why it fired: a freeze-frame of RPM, load, temps and voltages at the moment it happened, plus a human-readable cause — "IAT open — signal pegged 5.0V at key-on, expected 0.5–4.5V; check pin 72 / IAT connector." All persisted to an onboard blackbox log that survives power loss. |
| Gremlin capture | The hard ones. Momentary sensor dropouts, voltage sags, ground bounce, trigger glitches — logged with timestamp and full conditions even when they self-clear. "It does it sometimes" becomes a dated, documented event list you can act on. |
| Catches lying sensors | Cross-checks catch sensors that read in-range but wrong: MAP vs TPS vs RPM coherence, coolant-vs-air temp at cold soak, battery vs charging state — flagged as "implausible," distinct from open/short |
| Early warning | Trend monitoring watches values drifting toward their limits and raises a WATCH before the hard fault — built from documented 3S failure patterns: crank-angle sensors that fail as they warm up, knock-sensor and TPS grounds that corrode gradually, oil pressure sagging at steady state. Catch it when it starts, not a month down the line. |
| Electrical health | Charging-system monitor, alternator ripple, ground-integrity checks (sensor-ground offset detection), and supervision of every internal rail |
| The whole car | Beyond the engine: reads factory module codes (ABS, SRS, climate) over the diagnostic bus and folds them into one report |
| Guided troubleshooting | Every fault points to the fix: the suspect wire, both connector endpoints (ECU pin and factory pin), expected vs measured value, and the next check to run. The ECU is the shop manual for its own harness. |
| One-click report | Live per-circuit health dashboard in the tuner, one-click scan report, shareable log — hand your tuner or your forum thread the whole picture |