I have a 1996 Ford Bronco with the 5.8L that has an intermittent P0385 code. It generally runs and drives normally with no noticeable misfire or drivability problem.(FORScan shows no misfires during any of this)
The problem is very intermittent. At one point it went about a year without setting the code, then started happening every few weeks, and lately it has become somewhat more frequent but is still unpredictable.
What I’ve done/tested:
* Replaced the MD/MFDS (misfire detection) sensor more than once.
* Replaced the sensor pigtail/harness and have also checked the wiring for continuity.
* Previously ran/considered dedicated jumper wires to eliminate the factory harness as a possible source of interference/grounding issues.
* Checked the sensor resistance and found it within specification.
* Measured approximately 0.5V AC from the sensor while the engine is running.
* Had the harmonic balancer rebuilt/replaced, with no change to the problem.
* Removed and inspected the PCM. There is no obvious physical damage or damaged circuits.
* Had an electronics repair shop inspect the PCM. They reportedly checked the circuit, solder joints, capacitors, diodes and fuses. They traced the MD circuit to an IC/chip but said the circuit components themselves tested normally.
* KOER self-test does not reproduce the P0385.
* The code occurs during normal driving rather than immediately during KOER.
* With FORScan, the code will initially show as pending/“expected to be confirmed,” then later become confirmed after additional driving.
* When the code is not present, the engine appears to run normally and the OBD data looks generally healthy.
Unfortunately this has been an ongoing problem for years and it seems like every year or so the code comes on and I go down this rabbit hole. I’d like to fix it once and for all. Thank you!
The problem is very intermittent. At one point it went about a year without setting the code, then started happening every few weeks, and lately it has become somewhat more frequent but is still unpredictable.
What I’ve done/tested:
* Replaced the MD/MFDS (misfire detection) sensor more than once.
* Replaced the sensor pigtail/harness and have also checked the wiring for continuity.
* Previously ran/considered dedicated jumper wires to eliminate the factory harness as a possible source of interference/grounding issues.
* Checked the sensor resistance and found it within specification.
* Measured approximately 0.5V AC from the sensor while the engine is running.
* Had the harmonic balancer rebuilt/replaced, with no change to the problem.
* Removed and inspected the PCM. There is no obvious physical damage or damaged circuits.
* Had an electronics repair shop inspect the PCM. They reportedly checked the circuit, solder joints, capacitors, diodes and fuses. They traced the MD circuit to an IC/chip but said the circuit components themselves tested normally.
* KOER self-test does not reproduce the P0385.
* The code occurs during normal driving rather than immediately during KOER.
* With FORScan, the code will initially show as pending/“expected to be confirmed,” then later become confirmed after additional driving.
* When the code is not present, the engine appears to run normally and the OBD data looks generally healthy.
Unfortunately this has been an ongoing problem for years and it seems like every year or so the code comes on and I go down this rabbit hole. I’d like to fix it once and for all. Thank you!
Aug 15, 2026 at 7:29 PM
