Fault code 1898: Diagnosis/troubleshooting

WARNING: Danger of injury from limbs being trapped or severed.

NOTE: To gain access to the driver's memory seat adjustment control unit, tilt the driver's seat back.

NOTE: Visual inspection: In the next troubleshooting section, first check that the affected pins on the driver's memory seat adjustment control unit plug connection are not damaged or corroded. The wiring and plugs of the affected components must also be checked for external damage and correct contact. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair or replace damaged wires.

NOTE: Sporadic faults: In the event of sporadic faults, wiring points attached to moving parts on and in the vehicle must be checked systematically. Various statuses that can cause faults must be simulated with the help of the wiring diagram.

NOTE: Battery voltage: A battery voltage of between 11.4 and 14.5 V is required for the following troubleshooting procedure. This must be checked and provided, if necessary. On the vehicle electrical system, the voltage to the fuse (input side) must be guaranteed.

NOTE: In the wiring harness from the driver's memory seat adjustment control unit to the axial steering column adjustment sensor, there is a disconnection point which must be included in the checks.

DIAGNOSIS/TROUBLESHOOTING PROCEDURE

Work instruction			Display OK	If not OK
1	Visual inspection	Switch off ignition Check plug connection at axial steering column adjustment sensor, on driver's memory seat adjustment control unit and at disconnection point for damage (corroded or bent pins)	Go to Step 2	Repair plug → End
2	Check sensor for axial steering column adjustment	Use the 9588 Porsche System Tester II to switch to the menu 'Driver's seat actual values (position of steering column adjustment, Z-axis)' Move steering column from stop to stop in axial direction	Stop values approx. 29700 to 30150 Go to Step 9	Go to Step 3
3	Check voltage supply of sensor for axial steering column adjustment	Pull plug P off the driver's memory seat adjustment control unit Switch on ignition Measure voltage between pin 6 of driver's memory seat adjustment control unit plug P and ground. To do this, actuate the steering column adjustment	Approx. 12 V Go to Step 4	Go to Step 9
4	Check wires from driver's memory seat adjustment control unit to axial steering column adjustment sensor for short circuit to ground	Switch off ignition Pull plug P off the driver's memory seat adjustment control unit Pull plug off axial steering column adjustment sensor Measure resistance between pin 6 of control unit plug P and ground	∞ Ω Go to Step 5	The check relating to pin 6 is also to include pin 2 at the disconnection point and the jumper to pin 6 The check relating to pin 10 is also to include pin 7 at the disconnection point Repair wire → End
4		Measure resistance between pin 10 of control unit plug P and ground	∞ Ω Go to Step 5
5	Check wires from driver's memory seat adjustment control unit to axial steering column adjustment sensor for short circuit	Switch off ignition Measure resistance between pins 6 and 10 of control unit plug P	∞ Ω Go to Step 6	The check relating to pin 6 is also to include pin 2 at the disconnection point and the jumper to pin 6 The check relating to pin 10 is also to include pin 7 at the disconnection point Repair wire → End
6	Check wires from driver's memory seat adjustment control unit to axial steering column adjustment sensor for open circuit	Switch off ignition Measure resistance between pin 6 of control unit plug P and pin 6 of axial steering column adjustment sensor plug	< 5 Ω Go to Step 7	The check relating to pin 6 is also to include pin 2 at the disconnection point and the jumper to pin 6 The check relating to pin 10 is also to include pin 7 at the disconnection point Repair wire → End
6		Measure resistance between pin 10 of control unit plug P and pin 7 of axial steering column adjustment sensor plug	< 5 Ω Go to Step 7
7	Check wires from driver's memory seat adjustment control unit to axial steering column adjustment sensor for short circuit to B+	Switch on ignition Measure voltage between pin 6 of control unit plug P and ground	< 0.3 V Go to Step 8	The check relating to pin 6 is also to include pin 2 at the disconnection point and the jumper to pin 6 The check relating to pin 10 is also to include pin 7 at the disconnection point Repair wire → End
7		Measure voltage between pin 10 of control unit plug P and ground	< 0.3 V Go to Step 8
8	Replace steering column adjustment		→ End
9	Replace driver's memory seat adjustment control unit		→ End