- Joined
- May 4, 2026
- Messages
- 1
- Points
- 1
- City
- Wilmington
- State - Country
- DE - USA
- Vehicle Year
- 1998
- Vehicle
- Ford Ranger
- Drive
- 4WD
- Engine
- 4.0 V6
- Transmission
- Manual
Hello all,
Hoping the Ranger experts may have some advice. My '98 Mazda B4000 (4.0L, 6 cylinder) has a persistent P0340 code I can't seem to get rid of (Camshaft Position Sensor A Circuit (Bank 1 or single sensor)).
First, I replaced the CMP sensor. Old one definitely was in bad shape, but no luck. Then I tried rewiring the connector, because the old one was missing the clip. No luck. Then in a forum I read about a niche issue with a failing alternator causing this code for my engine, so I tried replacing that. Still no luck.
Anyone have any advice? The truck has no problem starting or driving; no knocks, no efficiency or performance issues, so I have no reason to believe the synchronizer has any problems. It would certainly seem to be electrical to me; maybe the PCM? I'm at my wit's end and I need to get it fixed so I can pass inspection and register my truck.
I don't know if this might be helpful, but after clearing the code or resetting the battery, it immediately comes back as a pending code, but the check engine light doesn't return until turning the truck off and on again. No other codes have appeared--just the P0340.
The previous owner also replaced the engine with another 4.0 from an automatic Explorer, and my truck is a manual, so I was wondering if something there could also be the root cause of the issue. He also said it was the same engine, but I'm wondering if maybe he swapped in a SOHC when my truck originally came equipped with a pushrod
Hoping the Ranger experts may have some advice. My '98 Mazda B4000 (4.0L, 6 cylinder) has a persistent P0340 code I can't seem to get rid of (Camshaft Position Sensor A Circuit (Bank 1 or single sensor)).
First, I replaced the CMP sensor. Old one definitely was in bad shape, but no luck. Then I tried rewiring the connector, because the old one was missing the clip. No luck. Then in a forum I read about a niche issue with a failing alternator causing this code for my engine, so I tried replacing that. Still no luck.
Anyone have any advice? The truck has no problem starting or driving; no knocks, no efficiency or performance issues, so I have no reason to believe the synchronizer has any problems. It would certainly seem to be electrical to me; maybe the PCM? I'm at my wit's end and I need to get it fixed so I can pass inspection and register my truck.
I don't know if this might be helpful, but after clearing the code or resetting the battery, it immediately comes back as a pending code, but the check engine light doesn't return until turning the truck off and on again. No other codes have appeared--just the P0340.
The previous owner also replaced the engine with another 4.0 from an automatic Explorer, and my truck is a manual, so I was wondering if something there could also be the root cause of the issue. He also said it was the same engine, but I'm wondering if maybe he swapped in a SOHC when my truck originally came equipped with a pushrod
