Home/Oldsmobile/Toronado Trofeo/Oldsmobile Toronado Trofeo (1990-1990)/Repair manual/Engine Controls - Tests W/codes - BCM/CODE B420 (B), TWILIGHT RELAY CIRCUITS

Contents

Section: Engine Controls - Tests W/codes - BCM

DESCRIPTION

OPERATION

IPC SEGMENT CHECK

EXIT SELF-DIAGNOSTICS

DISPLAYING TROUBLE CODES

CLEARING TROUBLE CODES

MANUAL OPERATION OF SERVICE MODE

SYSTEM SELECTION

TEST TYPE SELECTION

CLEAR CODES

DATA

INPUTS

OUTPUTS

OVERRIDE

SNAPSHOT

EXPLANATION OF SPECIFIC TEST SELECTION

MAKING SPECIFIC TEST SELECTION

BCM SNAPSHOT (NON-CRT EQUIPPED VEHICLES)

BCM SNAPSHOT (CRT EQUIPPED VEHICLES)

ECM SNAPSHOT (NON-CRT EQUIPPED VEHICLES)

ECM SNAPSHOT (CRT EQUIPPED VEHICLES)

STATUS LIGHT INDICATORS

DATA DISPLAY CODES

BCM DATA PARAMETERS

FOR CRT Control CODE

INPUT DISPLAY CODES

BCM INPUT PARAMETERS

IPC INPUT PARAMETERS

OUTPUT DISPLAY CODES

BCM OUTPUT PARAMETERS

OVERRIDE DISPLAY CODES

BCM OVERRIDE PARAMETERS

CHART A-1, NO SERVICE ENGINE SOON LIGHT

Diagnostic Aids

CHART A-2, SERVICE ENGINE SOON LIGHT WILL NOT GO OUT OR FLASH

NON-CRT EQUIPPED SELF-DIAGNOSTIC SYSTEM CHECK

CHART A, LOSS OF IPC DISPLAY NON-CRT EQUIPPED

CHART A-1, CENTRAL POWER SUPPLY (CPS) NON-CRT EQUIPPED

CHART B, LOSS OF SERIAL DATA NON-CRT EQUIPPED

CHART C, LOSS OF ECC COMMUNICATIONS NON-CRT EQUIPPED

CHART D, LOSS OF COMMUNICATIONS NON-CRT EQUIPPED

CHART D-1, GROUNDED SERIAL DATA CIRCUIT NON-CRT EQUIPPED

CHART D-2, SERIAL DATA CIRCUIT SHORTED TO VOLTAGE, NON-CRT EQUIPPED

COLOR CRT SELF-DIAGNOSTIC SYSTEM CHECK - CRT EQUIPPED

CHART A, LOSS OF IPC DISPLAY (CRT EQUIPPED)

CHART A-1, CENTRAL POWER SUPPLY (CPS) CHECK - CRT EQUIPPED

CHART B, COLOR CRT BLANK WITH IGNITION ON (CRT EQUIPPED)

CHART C, COLOR CRT UNABLE TO CONTROL ECCP (CRT EQUIPPED)

CHART D, SERIAL DATA CIRCUIT OPEN (CRT EQUIPPED)

CHART D-1, GROUNDED SERIAL DATA CIRCUIT (CRT EQUIPPED)

CHART D-2, SERIAL DATA CIRCUIT SHORTED TO VOLTAGE (CRT EQUIPPED)

CODE B110, OUTSIDE TEMP SENSOR CIRCUIT

Note On Intermittents

CODE B111, A/C HIGH SIDE TEMP SENSOR CIRCUIT

CODE B112, A/C LOW SIDE TEMP SENSOR CIRCUIT

CODE B113, IN-CAR TEMP SENSOR CIRCUIT

CODE B115, SUN LOAD SENSOR CIRCUIT

CODE B119, TWILIGHT PHOTOCELL CIRCUIT

CODE B120, TWILIGHT DELAY POTENTIOMETER CIRCUIT

CODES B120 & B122 TWILIGHT DELAY & PANEL DIMMING SIMULTANEOUSLY

CODE B121, TWILIGHT ENABLE SWITCH CIRCUIT

CODE B122, PANEL DIMMING POTENTIOMETER CIRCUIT

CODE B123, PANEL LAMP SWITCH CIRCUIT

CODE B124, VEHICLE SPEED SENSOR (VSS) CIRCUIT PROBLEM

CODE B127, GEAR SELECTOR SWITCH CIRCUIT

CODE B132, ENGINE OIL PRESSURE SENSOR CIRCUIT FAULTY

CODE B140, PHONE SYSTEM FAULT

CODE B332, LOSS OF COMPASS DATA

CODE B333, LOSS OF SIR DATA

CODE B334, LOSS OF ECM DATA

CODE B335, LOSS OF ECC OR CRTC SERIAL DATA

CODE B336, LOSS OF IPC SERIAL DATA

CODE B337, LOSS OF HVAC PROGRAMMER DATA

CODE B410, CHARGING SYSTEM CIRCUIT FAULT

CODE B411 OR B412 BATTERY VOLTAGE TOO HIGH OR TOO LOW

CODE B420, RELAY CIRCUITS

CODE B420 (A), COURTESY LAMP RELAY CIRCUITS

CODE B420 (B), TWILIGHT RELAY CIRCUITS

CODE B420 (C), FOG LIGHT RELAY CIRCUIT

CODE B420 (D), DIS CLOCK CIRCUIT

CODE B440, AIR MIX VALVE (DOOR) CIRCUIT PROBLEM

CODES B446, B447 & B448 REFRIGERANT SYSTEM PROBLEM (1 of 2)

CODES B446, B447 & B448 (2 of 2)

CODE B449, HIGH SIDE TEMPERATURE TOO HIGH

CODE B450, COOLANT TEMPERATURE TOO HIGH

CODE B482, ANTI-LOCK PRESSURE PROBLEM

Diagnosis

CODE B552, BCM KEEP ALIVE MEMORY ERROR

CODE B556, ODOMETER (EE) PROM ERROR

CODE B660, CRUISE CONTROL NOT IN DRIVE

CODE B663, CRUISE SPEED DIFFERENCE BETWEEN ACTUAL & SET IS TOO LARGE

CODE B664, CRUISE - ACCELERATION TOO HIGH

CODE B667, SET/COAST OR RESUME/ACCEL CIRCUIT SHORTED

CODE B671, CRUISE SERVO POSITION SENSOR CIRCUIT

CODE B672, CRUISE VENT SOLENOID CIRCUIT PROBLEM

CODE B673, CRUISE VACUUM SOLENOID CIRCUIT PROBLEM

CODE C710, CRTC SWITCHING CIRCUIT PROBLEM

LEFT DOOR OPEN MESSAGE

RIGHT DOOR OPEN MESSAGE

FUEL LEVEL IS LOW MESSAGE

WASHER FLUID IS LOW MESSAGE

SEAT BELT TELLTALE & CHIME

KEY IN IGNITION WARNING CHIME

FLASHING OR FULL HOT COOLANT GAUGE & FAST CHIME

HEADLIGHTS ARE ON CHIME

PARK BRAKE ON MESSAGE

BRAKE FLUID IS LOW MESSAGE

OIL PRESSURE LOW MESSAGE

OIL LEVEL IS LOW MESSAGE

HOT - IDLE ENGINE MESSAGE

HOT - STOP ENGINE MESSAGE

TURN SIGNAL ON MESSAGE

ANTILOCK TELLTALE ON

HEADLAMPS SUGGESTED MESSAGE

All sections

CODE B420 (B), TWILIGHT RELAY CIRCUITS Oldsmobile Toronado Trofeo

Engine Controls - Tests W/codes - BCM 1 illustration ~171 words

CODE B420 (B), TWILIGHT RELAY CIRCUITS

If headlights and parking lights did not cycle on and off when BO05 was selected, this is the system that set Code B420.

Note. Test numbers refer to numbers on diagnostic chart.

Test Number 1) Checks to see if fault is due to an open circuit or a short to ground in circuit. If headlights are always on, there is a short to ground in control circuit. If headlights never turn on, there is an open in one of the circuits.

Test Number 2) Checks to see if short to ground is due to circuit or BCM.

Test Number 3) Checks to see if open circuit is due to circuit or BCM.

Test Number 4) Checks to see if open circuit is on power or ground side of relay.

If an intermittent Code B420 is being set. Manipulate related wiring in output function and watch for relays to cycle.

Code B420 (B): Flow Chart Twilight Relay Circuit. Scheme 261

Scheme 261: Code B420 (B): Flow Chart Twilight Relay Circuit

Scheme 261: Code B420 (B): Flow Chart Twilight Relay Circuit