Home/Cadillac/Fleetwood/Cadillac Fleetwood II (1993-1996)/Repair manual/Engine Controls - Tests W/codes/CODE 70, A/C COMPRESSOR RELAY DRIVER

Contents

Wiring diagrams Section: Engine Controls - Tests W/codes

INTRODUCTION

SELF-DIAGNOSTIC SYSTEM

HARD FAILURES

INTERMITTENT FAILURES

DIAGNOSTIC PROCEDURE

RETRIEVING CODES (NON-SCAN)

READING TROUBLE CODES

TROUBLE CODE DEFINITION

HARD OR INTERMITTENT TROUBLE CODE DETERMINATION

CLEARING TROUBLE CODES

ECM/PCM LOCATION

Diagnostic Aids

Field Service Mode Check (If Available)

SPECIAL TOOLS (DIAGNOSTIC)

SCAN TESTER USAGE

SCAN DATA

ECM/PCM CODE CHARTS

CODE 11, MALFUNCTION INDICATOR LIGHT

CODE 13, OPEN OXYGEN SENSOR CIRCUIT

CODE 14, COOLANT TEMPERATURE SENSOR SIGNAL VOLTAGE LOW

CODE 15, COOLANT TEMPERATURE SENSOR SIGNAL VOLTAGE HIGH

CODE 16, OPTI-SPARK IGNITION SYSTEM LOW RESOLUTION PULSE

CODE 18, INJECTOR CIRCUIT

CODE 21, THROTTLE POSITION SENSOR SIGNAL VOLTAGE HIGH

CODE 22, THROTTLE POSITION SENSOR SIGNAL VOLTAGE LOW

CODE 23, MAT SENSOR SIGNAL VOLTAGE HIGH

CODE 24, VEHICLE SPEED SENSOR

CODE 25, MAT SENSOR SIGNAL VOLTAGE LOW

CODE 26, CANISTER PURGE SOLENOID

CODE 27, EGR SOLENOID VALVE

CODE 28, TRANSMISSION RANGE PRESSURE SWITCH

CODE 29, SECONDARY AIR INJECTION

CODE 32, EGR SYSTEM ERROR

CODE 33, MAP SENSOR SIGNAL VOLTAGE HIGH

CODE 34, MAP SENSOR SIGNAL VOLTAGE LOW

CODE 35, IAC IDLE SPEED ERROR

System Too Lean

System Too Rich

Throttle Body

IAC Valve Connections

PCV Valve

CODE 36, OPTI-SPARK HIGH RESOLUTION PULSE

CODE 37, TCC BRAKE SWITCH ERROR

CODE 38, TCC BRAKE SWITCH ERROR

CODE 41, OPTI-SPARK IGNITION SYSTEM OPEN OR SHORTED EST CKT

CODE 42

CODE 43, KNOCK SENSOR CIRCUIT

CODE 44, LEAN EXHAUST INDICATION

O2 Sensor Wire

Fuel Contamination

Fuel Pressure

Exhaust Leaks

Misfire Or Stall

CODE 45, RICH EXHAUST INDICATION

Fuel Pressure High

Ignition Ground

Evaporative Fuel Canister

MAP Sensor

TPS

O2 Sensor Contamination

EGR Problem

CODE 46, PASS-KEY CIRCUIT

CODE 46, PASS-KEY DIAGNOSIS

CODE 47, KNOCK SENSOR MODULE

CODE 48, MASS AIRFLOW SENSOR

CODE 50, SYSTEM VOLTAGE LOW

CODE 51, FAULTY PROM/MEM-CAL

CODE 52, FAULTY CAL-PAK

CODE 53, SYSTEM VOLTAGE HIGH

CODE 55, PCM ERROR

CODE 55, FUEL LEAN MONITOR

CODE 58, TRANSMISSION TEMPERATURE SENSOR HIGH TEMPERATURE

CODE 59, TRANSMISSION TEMPERATURE SENSOR LOW TEMPERATURE

CODE 61, A/C SYSTEM PERFORMANCE

CODE 66, A/C PRESSURE SENSOR

CODE 67, A/C PRESSURE SENSOR

CODE 68, A/C RELAY CIRCUIT SHORTED

CODE 69, A/C COMPRESSOR RELAY

CODE 70, A/C COMPRESSOR RELAY DRIVER

CODE 72, VSS

CODE 73, PRESSURE CONTROL SOLENOID

CODE 74, TRACTION CONTROL VOLTAGE LOW

CODE 75, TRANSMISSION VOLTAGE LOW

CODE 77, PRIMARY COOLING FAN DRIVER

CODE 78, SECONDARY COOLING FAN DRIVER

CODE 79, TRANSMISSION FLUID OVERTEMP

CODE 80, TRANSMISSION COMPONENT SLIPPING

CODE 81, 2-3 SHIFT SOLENOID

CODE 82, 1-2 SHIFT SOLENOID

CODE 84, 3-2 CONTROL SOLENOID

CODE 85, TCC STUCK ON

CODE 90, TCC SOLENOID CIRCUIT

CODE 95, CHANGE OIL LIGHT

CODE 96, LOW OIL LIGHT

CODE 97, VSS OUTPUT CIRCUIT

SUMMARY

All sections

CODE 70, A/C COMPRESSOR RELAY DRIVER Cadillac Fleetwood II

Engine Controls - Tests W/codes 1 illustration ~168 words

CODE 70, A/C COMPRESSOR RELAY DRIVER

Relay is supplied voltage when ignition is on. PCM controls solenoid valve by providing a ground through one of its Quad-Drivers Modules (QDM). When relay is actuated, terminal is grounded and its monitored voltage will be low. When an output is off, its terminal voltage will be high. Each QDM has a separate fault line to indicate presence of a current fault to control module central processor.

Note. Test numbers refer to numbers on diagnostic chart.

Tech-1 will enable circuit for 5 seconds.
This check can detect a partially shorted coil which would cause excessive current flow. Excessive current flow to a QDM will be detected as a fault and set a code.
The remaining checks will identify a circuit problem that has caused an excessive current flow or inoperative relay.

Check related harness connectors, including PCM harness. Check for damaged or pushed out terminals.

Code 70 Flow Chart (Fleetwood) A/C Compressor Relay Driver. Scheme 70

Scheme 70: Code 70 Flow Chart (Fleetwood) A/C Compressor Relay Driver

Scheme 70: Code 70 Flow Chart (Fleetwood) A/C Compressor Relay Driver