skynyrd
Club Guest
- Joined
- Apr 5, 2005
- Messages
- 4
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Hi all, i'm relatively new to the BMW Club and to this forum. You guys have a good thing going and seem to know what you're all talking about so I thought I'd post my problem here and beg for help! 
I took over this '96 318i (A) a short while back and as soon as I drove it home the first night, the EGS warning lamp (the little amber coloured gear sprocket with the exclamation mark in the middle) lit and the car went into failsafe mode (gear selector position 1 and 2 puts it in 3rd gear, position 3 and D puts it in 4th gear). Effectively, I've been driving around in 3rd and 4th gear.This car sat in the previous owners place for a 1 1/2 months without moving except for a start every 4 days. The owner was (rightfully) paranoid about taking the car out after I had confirmed the purchase. I thought that this may just be one of those problems that required 2 or 3 days of driving to clear off, but I was wrong in that the problem persisted, albeit intermittently.Thinking that the cause of the problem may be a screwed battery not supplying enough juice to the DME and the EGS, I changed the battery (the old one was due because the green indicator was no more). Battery used is an MF66 (Maintenance Free). This cleared the problem for a day and then it returned the next.When the car is cold (eg first thing in the morning), I can start it and drive normally (everything okay, EGS lamp off, transmission shifting like a beauty). About 5 mins into the drive, the damned lamp comes on and it goes into failsafe. I've measured the batt voltages (12.2 V engine off, 13.5 V engine running at idle).I took it for a MODIC inspection and a Launch inspection and both machines couldn't establish comms with the EGS. The DME, however, came out fine, flying colours, no fault codes. These tests were done with the engine hot, and the EGS lamp on. I suspect that when tested, the EGS would've been off. Haven't sent it for a reading when the thing's cold.As I understand it (from some wiring diagram PDF's I downloaded), the EGS lamp is fed from a steady voltage output from the instrument console that is held high by a series resistor. This output is fed into the EGS, which is itself sort of a open collector output. If everything's fine with the EGS, the unit energizes this open collector, and pulls the output of the instrument console to ground and the lamp goes off because it finds another path of less resistance through this open collector. I think the EGS shuts itself down and thereby switches on the warning lamp, which is why the diagnostic tools couldn't find it.So my theories are:1. Alternator not supplying enough juice, and when it gets hot, the alternators internal resistance increases, thereby making it less effective, and the EGS shuts down from under-voltage2. One or more of those damned tranny solenoids or temp sensor is screwed, although I doubt it because it shifts beautifully in the morning, or when it's cold.3. Screwed EGS.4. Buggered voltage regulator?5. Poor grounding?6. Faulty DME relay, maybe? (The DME relay also supplies power to the EGS module, I believe)I would really appreciate pointers, brickbats, insults, aggravation but most of all help and assistance from anyone out there who's had this problem, or can take a crack at figuring out what the hell is wrong.... :beaten:Also, would anyone know if the DME and the EGS control unit are one and the same, and if they're different, are they located at the same position, that is on the firewall behind the fuse box in the engine bay?Many many thanks!!Skynyrd
I took over this '96 318i (A) a short while back and as soon as I drove it home the first night, the EGS warning lamp (the little amber coloured gear sprocket with the exclamation mark in the middle) lit and the car went into failsafe mode (gear selector position 1 and 2 puts it in 3rd gear, position 3 and D puts it in 4th gear). Effectively, I've been driving around in 3rd and 4th gear.This car sat in the previous owners place for a 1 1/2 months without moving except for a start every 4 days. The owner was (rightfully) paranoid about taking the car out after I had confirmed the purchase. I thought that this may just be one of those problems that required 2 or 3 days of driving to clear off, but I was wrong in that the problem persisted, albeit intermittently.Thinking that the cause of the problem may be a screwed battery not supplying enough juice to the DME and the EGS, I changed the battery (the old one was due because the green indicator was no more). Battery used is an MF66 (Maintenance Free). This cleared the problem for a day and then it returned the next.When the car is cold (eg first thing in the morning), I can start it and drive normally (everything okay, EGS lamp off, transmission shifting like a beauty). About 5 mins into the drive, the damned lamp comes on and it goes into failsafe. I've measured the batt voltages (12.2 V engine off, 13.5 V engine running at idle).I took it for a MODIC inspection and a Launch inspection and both machines couldn't establish comms with the EGS. The DME, however, came out fine, flying colours, no fault codes. These tests were done with the engine hot, and the EGS lamp on. I suspect that when tested, the EGS would've been off. Haven't sent it for a reading when the thing's cold.As I understand it (from some wiring diagram PDF's I downloaded), the EGS lamp is fed from a steady voltage output from the instrument console that is held high by a series resistor. This output is fed into the EGS, which is itself sort of a open collector output. If everything's fine with the EGS, the unit energizes this open collector, and pulls the output of the instrument console to ground and the lamp goes off because it finds another path of less resistance through this open collector. I think the EGS shuts itself down and thereby switches on the warning lamp, which is why the diagnostic tools couldn't find it.So my theories are:1. Alternator not supplying enough juice, and when it gets hot, the alternators internal resistance increases, thereby making it less effective, and the EGS shuts down from under-voltage2. One or more of those damned tranny solenoids or temp sensor is screwed, although I doubt it because it shifts beautifully in the morning, or when it's cold.3. Screwed EGS.4. Buggered voltage regulator?5. Poor grounding?6. Faulty DME relay, maybe? (The DME relay also supplies power to the EGS module, I believe)I would really appreciate pointers, brickbats, insults, aggravation but most of all help and assistance from anyone out there who's had this problem, or can take a crack at figuring out what the hell is wrong.... :beaten:Also, would anyone know if the DME and the EGS control unit are one and the same, and if they're different, are they located at the same position, that is on the firewall behind the fuse box in the engine bay?Many many thanks!!Skynyrd
