Home/Chevrolet/Caprice Impala SS/Chevrolet Caprice Impala SS (1995-1996)/Repair manual/Engine Controls - Tests W/codes - 4.3l/CODE 28, TRANS. RANGE PRESSURE SWITCH

Contents

Wiring diagrams Section: Engine Controls - Tests W/codes - 4.3l

INTRODUCTION

Hard Failures

Intermittent Failures

DIAGNOSTIC PROCEDURE

READING TROUBLE CODES

TROUBLE CODE DEFINITION

HARD OR INTERMITTENT TROUBLE CODE DETERMINATION

CLEARING TROUBLE CODES

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, LEFT HEATED OXYGEN SENSOR CIRCUIT OPEN

CODE 14, COOLANT TEMP SENS SGNL VLTGE LOW (HI TEMP INDICATED)

CODE 15, COOLANT TEMP SENSOR SIGNAL VOLTAGE LOW

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, IAT SENSOR SIGNAL VOLTAGE HIGH (LOW TEMP INDICATED)

CODE 24, VEHICLE SPEED SENSOR

CODE 25, IAT SENSOR SIGNAL VOLTAGE LOW (HIGH TEMP INDICATED)

CODE 26, CANISTER PURGE SOLENOID

CODE 27, EGR SOL VALVE

CODE 28, TRANS. 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 36, OPTI-SPARK HIGH RESOLUTION PULSE

CODE 37, TCC BRAKE SWITCH ERROR

CODE 38, BRAKE SWITCH ERROR

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

CODE 42, IC CIRCUIT GROUNDED

CODE 43, KNOCK SENSOR CIRCUIT (DUAL SENSORS)

CODE 44, LEFT HEATED OXYGEN SENSOR LEAN EXHAUST INDICATION

O2 Sensor Wire

Fuel Contamination

Fuel Pressure

Exhaust Leaks

Misfire Or Stall

CODE 45, LEFT HEATED OXYGEN SENSOR RICH EXHAUST INDICATION

Fuel Pressure High

Ignition Ground

Evaporative Fuel Canister

MAP Sensor

TPS

O2 Sensor Contamination

EGR Problem

CODE 46, PASS-KEY CIRCUIT

Pass-Key Diagnosis

CODE 47, KNOCK SENSOR MODULE

CODE 48, MASS AIRFLOW SENSOR

CODE 50, SYSTEM VOLTAGE LOW

CODE 52, FAULTY CAL-PAK

CODE 53, SYSTEM VOLTAGE HIGH

CODE 55, PCM ERROR

CODE 55, FUEL LEAN MONITOR

CODE 58, TRANS TEMPERATURE SENSOR HIGH TEMPERATURE

CODE 59, TRANS. TEMPERATURE SENSOR LOW TEMPERATURE

CODE 63, RIGHT HEATED OXYGEN SENSOR CIRCUIT OPEN

CODE 64, RIGHT HEATED OXYGEN SENSOR LEAN EXHAUST INDICATION

CODE 65, RIGHT HEATED OXYGEN SENSOR RICH EXHAUST INDICATION

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, VEHICLE SPEED SENSOR LOSS

CODE 73, PRESSURE CONTROL SOLENOID

CODE 75, TRANSMISSION VOLTAGE LOW

CODE 77, PRIMARY COOLING FAN DRIVER

CODE 78, SECONDARY COOLING FAN DRIVER

CODE 79, TRANSMISSION FLUID OVERTEMP

CODE 81, 2-3 SHIFT SOLENOID

CODE 82, 1-2 SHIFT SOLENOID

CODE 83, TCC PWM SOLENOID - A/T

CODE 84, 3-2 CONTROL SOLENOID - WITH A/T

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 28, TRANS. RANGE PRESSURE SWITCH Chevrolet Caprice Impala SS

Engine Controls - Tests W/codes - 4.3l 2 illustrations ~183 words

CODE 28, TRANS. RANGE PRESSURE SWITCH

Transmission range pressure switch assembly consists of 5 pressure switches (2 normally closed, 3 normally open), and a fluid temperature sensor combined into one unit and mounted on the valve body. PCM supplies voltage to each range signal. By grounding one or more of these circuits through various combinations of pressure switches, PCM detects which manual valve position has been selected. With ignition on and engine off, Park/Neutral will be indicated. Code 28 will set when range signals "A" and "C" are both zero volts (on) for 2 seconds.

Note. Test numbers refer to numbers on diagnostic chart.

Checks indicated range signal to valve position signal actually selected.
Checks for correct voltage from PCM to transmission external connector.
Checks for short to ground in any one of the 3 valve position circuits.

Code will set if PCM detects one of 2 illegal combinations. Check all connections for good contact.

Code 28 Schematic (Caprice) Transmission Range Pressure Switch. Scheme 27

Scheme 27: Code 28 Schematic (Caprice) Transmission Range Pressure Switch

Scheme 27: Code 28 Schematic (Caprice) Transmission Range Pressure Switch

Code 28 Diagnostic Flow Chart (Caprice) Transmission Range Pressure Switch. Scheme 28

Scheme 28: Code 28 Diagnostic Flow Chart (Caprice) Transmission Range Pressure Switch

Scheme 28: Code 28 Diagnostic Flow Chart (Caprice) Transmission Range Pressure Switch