PSM, Introduction

Introduction

PSM 5.3 (Porsche Stability Management)
Diagnosis software number: PSM04XX

911 Carrera 4 (996) as of model year 1999 (x)

PSM 5.7 (Porsche Stability Management)
Diagnosis software number: PSM05XX

911 Carrera (996)/911 Carrera 4 (996) as from model year 2000 (Y)

NOTE: PSM was first installed as standard in the 911 Carrera 4 in 1999. This system is marked by PSM 5.3. System PSM 5.7 is installed in the 911 Carrera 4 and on request in the 911 Carrera 2 from 2000. The scope of functions is the same in both vehicles. The booster pump of the 911 Carrera 2 is not located at the hydraulic unit as in the 911 Carrera 4 but on the opposite side at the front end of the vehicle.

For a perfect functioning of the system, the following points must be observed:
- The battery must be securely connected.
- The brake fluid level must be at the correct level.
- The system must not leak.
- Tyre size, air pressure and the condition of the tyres must be satisfactory.

General instructions/safety instructions
The following points must be observed during vehicle diagnosis:
- If the control module is damaged (PSM 5.7), the complete hydraulic unit with integrated control module must be replaced. The control module is separate from the hydraulic unit in the PSM 5.3 and can be replaced without the hydraulic unit.
- When replacing a PSM control module, observe the coding of the control module (vehicle type, transmission type and chassis number).
- The steering-angle sensor must be calibrated after all work on the running gear.
- After troubleshooting or repairs, erase the fault memory with the Porsche System Tester 2 and carry out a test drive.
- After the test drive, read out the fault memory with Porsche System Tester 2 again.

CAUTION: Danger of damage due to improper handling of the battery and the control module connectors!
- Never disconnect battery with engine running.
- Never start engine without securely connected battery.
- Never pull off or push on plug connections of the control modules or other electronic components when the ignition is switched on.

General information on the fault memory
The fault memory of the control module can save up to three different faults simultaneously. If all three fault memories are occupied, the new fault overwrites the oldest fault. It is possible to reset faults in the control module only after an "ignition off-on" procedure. The fault memory content of the PSM control module is maintained even in removed state.

Fault memory key [F8]
In order to be able to assess the fault exactly, the fault memory key [F8] must be pressed. This information should be saved using the [F4] key and printed out. If a fault code is stored with "not present" status and no other problems are present, then the fault memory must be erased.

-----/Signal implausible/no signal change/open circuit or short to ground/short circuit to B+
-----: No details available.
Signal implausible: The incoming signal to the control module deviates from the signal expected.
No signal change: The incoming signal to the control module does not change.
Open circuit of short circuit to ground: There is (present) or was (not present) a short circuit to ground or an open circuit in the circuit to the control module terminal.
Open circuit to short circuit to B+: There is (present) or was (not present) a short circuit to voltage or an open circuit in the circuit to the control module terminal.
Short circuit to ground: There is (present) or was (not present) a short circuit to ground in the circuit to the control module terminal.
Short circuit to B+: There is (present) or was (not present) a short circuit to voltage in the circuit to the control module terminal.

Light on
PSM light switched on.

Present/not present
The fault is detected as present or not present.