The most common cause for this Porsche 968 B1004 type of failure is due to liquids spilled on the upshift/downshift switch. Open or shorted electrical wiring, damaged, corroded, or disconnected wiring or connectors are also a viable possibility.
Common Symptoms For Porsche 968 B1004
A scanner (or code reader) and a digital volt/ohmmeter will be required to successfully diagnose this code. Virtually every vehicle (with an automatic transmission) produced since the mid-eighties is equipped with some type of computer controlled automatic transmission system
Repair or replace any open, shorted, damaged, or corroded items as required and retest the system to make sure that repairs were successful
After the codes are cleared, test drive the vehicle to see if the code returns
If either the reference voltage or ground circuits are open, use the digital volt/ohmmeter to check for continuity (disconnect all related control modules from the circuit before checking circuit resistance or controller damage may occur) and resistance in all circuits
Accelerator Pedal Position (APP) Sensor 1 Performance
Control Module Throttle Actuator Position Performance
Transmission Control Module Reprogrammable Memory
Porsche 968 B1004 Troubleshooting
Broken engine mountings can cause banging and graunching noises. There are two main types of mounting those centrally placed close to the bottom of the block and those higher up the block which mount on to the inner wings or chassis members. Porsche 968 B1004 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.
How to turn off Porsche 968 B1004 check engine light ?
There are two ways to turn off the check engine light:
A repair technician can do so once repairs have been made.
The OBD II can automatically turn it off when it fails to detect the problem after several diagnostic cycles.