Home/Porsche/Boxster/Porsche Boxster 986 (1996-2002)/Repair manual/Dme 5.2.2 Diagnosis/A/C compressor control - upper limit exceeded

Contents

Wiring diagrams Section: Dme 5.2.2 Diagnosis

Structure

General

Operating conditions "Freeze frame"

ECM signal output

Warm up cycle

Driving cycle

Trip

Readiness code

Freeze Frame

Fault shedding

Fault healing

Fault erasing counter

Use

Malfunctions

Voltage supply

Adjusting illumination of LCD panel

Working log

Automatic switch-off

Software update

Main menu

Fault memory

Erase fault memory

Actual values

Drive links

Input signals

Drive link active

Vehicle data

Control module programming

Mode 1

Mode 2

Mode 4

Mode 5

$00 Supported PID's

Data A

Data B

Data C

Data D

$OF Intake air temperature

Mode 3

Tools

Fault types

MIL (Check Engine Malfunction Indicator Light)

Mass Air Flow Sensor Signal implausible

Mass Air Flow Sensor, below lower limit

Function

Intake Air Temperature Circuit - Low Input

Intake Air Temperature Sensor, below lower limit

Check Intake Air Temperature Sensor in mass air flow sensor

ECT Sensor signal implausible

ECT Engine Coolant Temperature - Malfunction

Resistance values

Check Intake Air Temperature Sensor

Check Output Voltage of ECM

117 Throttle Position Sensor - Below Limit

Check voltage supply to TP sensor

Check TP sensor

Check oxygen sensor

Check ECM final stage

Aging of Oxygen Sensor Ahead of Three Way Catalytic Converter (TWC) (cylinders 1 - 3)

Aging of Oxygen Sensor Ahead of Three Way Catalytic Converter (cylinders 1 - 3) - Below Lower Limit

Aging of Oxygen Sensor Ahead of Three Way Catalytic Converter (TWC) (cylinders 4 - 6)

Manual transmission

Tiptronic

Check function of oxygen sensor

Check oxygen sensor heating

Aging of Oxygen Sensor After Three Way Catalytic Converter (TWC) (cylinders 1 - 3)

Camshaft Position (CMP) Sensor 1 Signal Implausible, Short Circuit to Ground, Short Circuit to Plus

Check power supply to CMP Sensor

Check CMP Sensor signal

Check signal wire from ECM to CMP Sensors

Check signal wire from ECM to CMP Sensors for short circuit to ground

Check signal wire from ECM to CMP Sensors for short circuit to B+

Oil Temperature Sensor - Short Circuit to Ground

Check temperature sensor

Check wire from ECM to temperature sensor for short to ground

Check wire from ECM to temperature sensor for short to B+

Misfire Damaging to Catalytic Converter

Misfire, Cylinder 1, Damaging to Catalytic Converter

Misfire, Cylinder 2, Damaging to Catalytic Converter

Misfire, Cylinder 3, Damaging to Catalytic Converter

Misfire, Cylinder 4, Damaging to Catalytic Converter

Misfire, Cylinder 5, Damaging to Catalytic Converter

Misfire, Cylinder 6, Damaging to Catalytic Converter

Misfire, Cylinder 1, Emission Related

Misfire, Cylinder 2, Emission Related

Misfire, Cylinder 3, Emission Related

Misfire, Cylinder 4, Emission Related

Misfire, Cylinder 5, Emission Related

Misfire, Cylinder 6, Emission Related

Misfire, Emission Related

Checking quantity delivered by fuel pump

Check triggering of fuel injectors

Check signal with engine tester

Secondary Air Injection System - Signal Implausible (Cylinders 1 - 3)

In menu "Drive links", trigger secondary air injection (AIR) pump

Check triggering of AIR pump

Check electric change-over valve

Check air change-over valve and air supply lines

TWC Conversion Too Low (cylinders 1 - 3)

Check triggering of the EVAP canister purge valve

Check voltage supply and leads

Check EVAP canister purge valve

Check hose between EVAP canister purge valve and intake system

Check EVAP canister purge valve for leaks

Check ventilation lines for leaks

EVAP Canister Purge Valve - Open Circuit

Check voltage supply for EVAP canister purge valve

Check control line for EVAP canister purge valve

Check control line for EVAP canister purge valve for short circuit to B+

Check control line for EVAP canister purge valve for short circuit to ground

Check purge air line for blockage

96 EVAP Canister Shutoff Valve (Output Stage) - Open Circuit

Check voltage supply for shutoff valve

Check shutoff valve

Check triggering wire for shutoff valve for continuity

Check triggering wire for shutoff valve for short circuit to B+

Check triggering wire for shutoff valve for short circuit to ground

99 Tank Pressure Sensor - Signal Implausible

99 Tank Pressure Sensor - Below Limit

Check tank cap

Check ventilation lines at EVAP canister

Check ventilation lines at operating purge valve

Check ventilation line at tank

Check ventilation line at EVAP canister purge valve

Check ventilation lines

Read ABS control module fault memory

Check speed sensor with ohmmeter

Check speed signal with engine tester

Idle Air Control - Engine speed too low

Check IAC Valve

Check CAN bus from ECM to Tiptronic control module for continuity

Check CAN bus from ECM to Tiptronic control module for short to ground

Check CAN bus from ECM to Tiptronic control module for short to B+

Check CAN bus from ECM to Tiptronic control module for short circuit

ECM faulty

Oxygen sensor heating 1 ahead of catalytic converter - above upper limit

Check resistance of oxygen sensor heating

Oxygen sensor heating 1 behind catalytic converter - above upper limit

Oxygen sensor heating 1 ahead of catalytic converter - below lower threshold

Oxygen sensor heating 1 behind catalytic converter - below lower threshold

Check resistance of H02S heating

Check ECM final stage to B+

Oxygen Sensing Adaptation Range 1 (Cylinders 1 - 3) Enrichment Limit

Checking fuel pressure

Checking volume supply of fuel pump

Fuel injectors contaminated (carbonized)

Oxygen Sensing Adaptation Range 1 (Cylinders 1 - 3) Lean Limit

Check fuel pressure regulator, vacuum connection and fuel return line

Oxygen Sensing Adaptation Range 2 (Cylinders 1 - 3) Lean Limit

Oxygen Sensing Adaptation Range 2 (cylinder 1 - 3) - Enrichment limit

Fuel injectors contaminated, carbonized

Read specified values for Throttle Position Sensor

Engine Compartment Temperature Sensor - Short Circuit to Ground

Resistance value

Check wire from ECM to temperature sensor for short circuit to ground

Check wire from ECM to temperature sensor for short circuit to B+

Injector Circuit Cylinder 1 - Short to B+

Fuel injector, cylinder 1 - Short to Ground

Check fuel injector

Injector Circuit, Cylinder 2 - Short to B+

Fuel Injector, cylinder 2 - Short to Ground

Fuel Injector, cylinder 3 - Short to B+

Fuel Injector, cylinder 3 - Short to Ground

Injector Circuit, Cylinder 4 - Short to B+

Fuel Injector, cylinder 4 - Short to Ground

Fuel Injector, cylinder 5 - Short to B+

Fuel Injector, cylinder 5 - Short to Ground

Fuel Injector, cylinder 6 - Short to B+

Fuel Injector, cylinder 6 - Short to Ground

Timing Chain out of Position, Bank 2 - Below Lower Limit

Timing Chain out of Position, Bank 2 - Above Upper Limit

Timing Chain out of Position, Bank 1 - Below Lower Limit

Knock Sensor 1 - Signal Implausible

Knock Sensor 2 - Signal Implausible

A/C compressor control - Interruption

A/C compressor control - upper limit exceeded

Check control wire for A/C relay, pin 2 for interruptions

Check control wire for A/C relay, pin 2 for short circuit to B+

Check control wire for A/C relay, pin 2 (terminal 85) for short circuit to ground

End Stage Fuel Pump Relay - Short Circuit to Ground

End Stage Fuel Pump Relay - Short Circuit to Plus

P 1502

Check fuel pump relay

Idle Control Valve Opening Coil - Open

Check coil resistance of IAC Valve

Check triggering wire for short to ground

Check B+ supply of actuator

Check triggering wire for continuity

Idle Air Control (IAC) Valve - Interruption

Idle Air Control (IAC) Valve Closing Coil - Below Lower Limit

Check signal wire for continuity

Check signal wire for short circuit to ground

Check signal wire for short circuit to B+

Power Supply - Signal Implausible

Power Supply - Below Lower Limit

Check wire, terminal 30, for contact resistances

Engine Compartment Purge Fan End-Stage - Open Circuit

Engine Compartment Purge Fan End-Stage - Short Circuit to Ground

Check relay

Check wire from ECM to relay for continuity

Check wire from ECM to relay for short circuit to ground

Check wire from ECM to relay for short circuit to B+

Fan End-Stage - Open Circuit

Fan End-Stage - Short Circuit to Ground

Check both relays

Check wire from ECM to relays for continuity

Check wire from ECM to relays for short circuit to ground

Check wire from ECM to relays for short circuit to B+

Malfunction Indication Light (MIL), Check engine - Interruption

MIL Check engine - Short Circuit to Ground

All sections

A/C compressor control - upper limit exceeded Porsche Boxster 986

Dme 5.2.2 Diagnosis

A/C compressor control - upper limit exceeded

Note. For diagnosis, see P1457 .

The magnetic clutch for the A/C compressor is supplied with battery voltage via a relay.

The coil of the relay is supplied with battery voltage by the ECM on one side and with ground by the ECM on the other. The diagnosis only monitors the wiring from the ECM, pin 62 to the A/C relay, terminal 85.