Home/Cadillac/Fleetwood/Cadillac Fleetwood II (1993-1996)/Repair manual/Engine Controls - Tests W/codes/CODE 35, IAC IDLE SPEED ERROR

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 35, IAC IDLE SPEED ERROR Cadillac Fleetwood II

Engine Controls - Tests W/codes ~247 words

CODE 35, IAC IDLE SPEED ERROR

Code 35 will set when closed throttle engine speed is 150 RPM greater or less than correct idle speed for 20 seconds.

Note. Test numbers refer to numbers on diagnostic chart.

Tech 1 RPM control mode is used to extend and retract IAC valve. Movement is verified by an engine speed change. If no change in speed occurs, valve can be retested when removed from throttle body. If IAC valve is retracted beyond control range (about 1500 RPM), many flashes in extend position may occur before engine speed begins to drop. This is normal on certain engines. Fully extending IAC may cause engine to stall. This may be normal.
This test uses Tech 1 to command IAC-controlled idle speed. Control module issues commands to obtain requested idle speed. Each light on node light should flash Red and Green while IAC valve is cycled. While sequence of color is not important, check circuits for faults beginning with poor terminal contacts if either light is off or does not flash Red and Green.

A slow, unstable idle may be caused by a system problem which cannot be overcome by IAC. Scan counts will be greater than 60 if idle is too low and zero counts if idle is too high. If idle is too high, stop engine. Fully extend IAC with driver. Start engine. If idle speed is greater than 800 RPM, look for possible vacuum leaks.