BMW Starter Motor Problems and Faults

No Start Caused by Faulty Oil Level Switch

Model:
BMW E39 (5 series) with M52 engine, BMW E46 (3 series) Vehicles up to November 1998.
Complaint:
The vehicle will not start. Other problems the vehicle may experience are as follows:

-No transmission range display in the instrument cluster.
-Charge indicator lamp can flicker or it is permanently on.
-Fault code 11 the oil level switch is stored in the instrument cluster (E46)
-Fuse 15 (E39) or fuse 30 (E46) is blown.

This can be due to a faulty oil level switch which can cause the fuse to blow. If this happens a loss of input to EWS from the Transmission Range Switch can occur.
Remedy:
Check fuse 15 and fuse 30 if they are both blown then replace the fuses (7.5A). Start the engine. If the fuse blows again, disconnect the oil level switch at the plug connector, install a new fuse and restart the engine. If the engine starts, and the range display is restored in the Instrument Cluster then replace the oil level switch. In order to confirm whether a switch is defective use a DVM and check the resistance between the pins of the 3 pin connector. A good switch will measure infinite resistance between any 2 pins in the connector.

Starter Cable

Model:
BMW 325 (All)
Complaint:
The starter cable could rub against the brake booster. All cars produced before January 1986 should be checked.
Remedy:

-Disconnect the battery ground cable.
-Loosen the starter cable nut.
-Push the cable towards the engine and tighten the nut. (The cable should be against the stop shoulder of the solenoid.)
-Fasten the starter cable to the engine wiring harness with a cable tie.
-Reconnect the battery ground cable.

Vehicle will not start

Model:
BMW 325e
Complaint:
Although the starter will engage, the instrument panel lights are on, and other electrical items can be operated, the vehicle will not start.
Remedy:
This could be caused due to no voltage at the battery junction block at the 6mm2 black wire, which is located in the engine compartment, which will result in no electrical current to the DME main relay and fuel pump.
To remedy:
Open the harness and inspect the fusible link which is located approx 6 inches from the battery + terminal. If the fusible link is open then use an ohmmeter on the vehicle side of the link to ascertain if a short to the ground has caused the fusible link to open. Replace the fusible link if:

- A short to the ground is discovered. Correct the short before replacing the fusible link.
- No short is found then the fusible link open may be due to a brief overload.

Binding/Sticking Ignition – Starter Motor Failures

Model:
BMW E30,BMW E31, BMW E32, BMW E34, BMW E36 vehicles produced before June 1994
Complaint:
Some vehicles have experienced failed starters usually after the vehicle is turned off. Proceeding this failure vehicles have experienced problems such as loss of sunroof, window, and seat heating, also a discharged battery as a result of continued starter engagement, and a whirring noise under the hood after starting. It is a possibility that these problems may occur on a vehicle which has been equipped with an automatic transmission. Therefore the gear selection switch will cause the starter to disengage as soon as the vehicle is shifted into drive or reverse, but will re-engage with the running engine if the gear is placed in neutral or park causing a loud grinding noise and potential flywheel/starter pinion damage.
Remedy:
When a vehicle with a failed starter is located, or complaints about the vehicle are similar to those listed above, the starter electrical system including the unloader relay circuits must be checked for correct function. The starter pinion and flywheel teeth should also be checked in case they have scouring or other mechanical damage which would cause misalignment or improper mounting surfaces.
If the starter electrical system and flywheel/pinion does not reveal a problem, then the ignition cylinder/lock assembly is the cause of the prolonged starter engagement. All of the mechanical portion of the steering lock must be replaced with the electrical ignition switch. If the starter is damaged that too must be replaced.
On E36 vehicles produced before June 1994 the starter protection function can be retrofitted. E36 vehicles produced prior to January 1994 require the installation of a relay socket, adapter harness, and a starter protection relay. E36 vehicles produced prior to September 1992 with the M50 engine will also require a resistor adapter in series with the black wire of the adapter harness to be installed. Vehicles that are produced from January 1994 till June 1994 only require the addition of one wire and a new relay which has the starter protection feature.

Clutch Switch for Starter Motor Interlock

Model:
BMW Z3 roadster, BMW Z3 coupe (E36/7). Vehicles which have manual transmission.
Complaint:
A no-start situation may arise due to the wiring harness being routed to the clutch switch in such a way that it is permanently under tension and could become damaged.
Remedy:
Utilize the ‘Service Menu’ of the Dealer Communication System, and based upon the response of the system either proceed with corrective action, or take no action at all.

Service Action to Recode General Module

Model:
BMW E38 (7 series), BMW E39 (5 series). Vehicles produced from August 1998 to November 1998
Complaint:
If the boot lock is set to horizontal or ‘Valet’ position, a discharged battery could result when the vehicle is parked. This is due to the vehicle electrical system neglecting to go into consumer cut off.
Remedy:
Utilize the ‘Service Menu’ of the Dealer Communication System, and based upon the response of the system either proceed with corrective action, or take no action at all.

Boot Harness Cut or Broken at Hinge

Model:
BMW Z3 roadster, BMW M roadster
Complaint:
If the boot harness is cut or broken it may cause the boot lock motor, power locks and windows to be inoperative, a no start situation, or the fuel gauge, clock, or board computer to be inoperative.
Remedy:
Install a new boot harness.

Send/Receive (S/E) Module for EWS II

Model:
BMW 3 Series (E36), BMW 5 series (E39) vehicles produced between January 1997 and February 1997
Complaint:
Due to the installation of new software (EWS II Software Version 3) a possible incompatibility has arisen between the S/E Module and the EWS II Module which could lead to the keys failing to start the engine.
Remedy:
Utilize the ‘Service Menu’ of the Dealer Communication System, and based upon the response of the system either proceed with corrective action, or take no action at all.
If corrective action is needed then replace the S/E Module with EWS II Software Version 3. Also replace ESW II Module and all defective keys.

Faulty Ignition/Starter Switch

Model:
BMW 5 Series (E39), BMW 7 Series (E38)
Complaint:
A possibility of poor contact in the ignition/starter switch through production tolerances could lead to problems starting the vehicle at a later date.
Remedy:
Utilize the ‘Service Menu’ of the Dealer Communication System, and based upon the response of the system either proceed with corrective action, or take no action at all. If corrective action is necessary then replace the ignition/starter switch.
Please note: The switch must not be mounted with its weight on one side, therefore tighten the two grub screws alternately to avoid misaligning the switch. Before the cable connector is connected check the ignition key snaps back from position 3.

Various Functions Inoperative on Instrument Cluster

Model:
BMW E38, BMW E39, Model 1998
Complaint:

-Some functions on the instrument cluster with integrated IKE are inoperative or locked up.
- When the power is turned off the instrument cluster may not fully power down which can lead to a dead battery. If the transmission range signal is lost a no start situation will occur.

These can be caused by:

-Use of the OBC code could occasionally cause the loss of K-Bus communications between the IKE and General Module. (The OBC code is the security code added in to the board computer or MID by the vehicle owner when exiting the vehicle and re-entering the vehicle.)
-An error in Instrument Clusters with software lower than SW11.0.

Remedy:
Fit replacement Instrument Cluster SW11.0, or higher.