Hard Failures
Hard failures cause MIL to glow and remain on until malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, determine cause of malfunction using self-diagnostic tests. If a sensor fails, PCM will use a substitute value in its calculations, allowing engine to operate in limp-in mode. In this condition, vehicle will run, but driveability may be poor.
Intermittent Failures
Intermittent failures may cause MIL to flicker or stay on until intermittent trouble code goes away. However, PCM memory will retain corresponding trouble code. If related trouble code does not reoccur within a certain time frame, related trouble code will be erased from PCM memory. Intermittent failures can be caused by a failed sensor, bad connector or wiring related problems.
SERVICE PRECAUTIONS
During diagnosis, following these precautions
- Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. See «FUEL PRESSURE RELEASE»(ref-10877-S41851772352000111300000) .
- When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See «COMPUTER RELEARN PROCEDURES»(ref-10824) article in GENERAL INFORMATION section before disconnecting battery.
- Vehicle must have a fully charged battery and functional charging system.
- Probe PCM 60-pin connector from pin side. DO NOT backprobe PCM connector.
- DO NOT cause short circuits when performing electrical tests. This will set additional trouble codes, making diagnosis of original problem more difficult.
- DO NOT use a test light instead of a voltmeter.
- When checking for spark, ensure coil wire is no more than 1/4" from ground. If coil wire is more than 1/4" from ground, damage to vehicle electronics and/or PCM may result.
- DO NOT prolong testing of fuel injectors, or engine may hydrostatically (liquid) lock.
- Always repair lowest trouble code number (CHECK ENGINE light) or first trouble code displayed (DRB) first.
- Always perform verification procedure test after repairs are made.
- Always disconnect DRB after use.
- Always disconnect DRB before charging battery.
FUEL PRESSURE RELEASE
| CAUTION | ALWAYS relieve pressure before disconnecting any fuel injection-related components. DO NOT allow fuel to contact engine or electrical components. |
Disconnect negative battery cable. Loosen fuel filler cap to release tank pressure. Remove protective cap from pressure test port on fuel rail. Using appropriate fuel pressure gauge/hose with gauge removed, place gauge end of hose into approved gasoline container. To release pressure, screw other end of hose onto pressure test port. After pressure is released, remove hose from test port and install protective cap.
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
Code 11
DRB displays NO CRANK REFERENCE SIGNAL AT PCM. Condition is: no crankshaft reference signal detected during cranking.
Code 12
DRB displays BATTERY DISCONNECT. Condition is: Direct battery input to Powertrain Control Module (PCM) disconnected within last 50 key-on cycles.
Code 13
DRB displays SLOW CHANGE IN IDLE MAP SENSOR SIGNAL. Condition is: Manifold Absolute Pressure (MAP) sensor output change slower and/or smaller than expected.
DRB displays NO CHANGE IN MAP FROM START TO RUN. Condition is: no difference recognized between Manifold Absolute Pressure (MAP) reading and barometric (atmospheric) pressure reading at start-up.
Code 14
DRB displays MAP VOLTAGE TOO LOW. Condition is: Manifold Absolute Pressure (MAP) sensor input less than minimum acceptable voltage.
DRB displays MAP VOLTAGE TOO HIGH. Condition is: Manifold Absolute Pressure (MAP) sensor input more than maximum acceptable voltage.
Code 15
DRB displays NO VEHICLE SPEED SENSOR SIGNAL. Condition is: no Vehicle Speed Sensor (VSS) signal detected with road load conditions.
Code 17
DRB displays ENGINE IS COLD TOO LONG. Condition is: coolant temperature stays less than normal operating temperature during vehicle operation.
Code 21
DRB displays O2S STAYS AT CENTER. Condition is: no rich or lean signal detected from oxygen sensor input.
DRB displays O2S SHORTED TO VOLTAGE. Condition is: oxygen sensor input voltage maintained at more than normal operating range.
Code 22
DRB displays ECT SENSOR VOLTAGE TOO LOW. Condition is: Engine Coolant Temperature (ECT) sensor input less than minimum acceptable voltage.
DRB displays ECT SENSOR VOLTAGE TOO HIGH. Condition is: Engine Coolant Temperature (ECT) sensor input more than maximum acceptable voltage.
Code 23
DRB displays INTAKE AIR TEMPERATURE SENSOR VOLTAGE LOW. Condition is: Intake Air Temperature (IAT) sensor input less than minimum acceptable voltage.
DRB displays INTAKE AIR TEMPERATURE SENSOR VOLTAGE HIGH. Condition is: Intake Air Temperature (IAT) sensor input more than maximum acceptable voltage.
DRB displays THROTTLE BODY TEMP VOLTAGE HIGH. Condition is: throttle body temperature input is more than maximum acceptable voltage.
DRB displays THROTTLE BODY TEMP VOLTAGE LOW. Condition is: throttle body temperature input is less than maximum acceptable voltage.
Code 24
DRB displays THROTTLE POSITION SENSOR VOLTAGE LOW. Condition is: Throttle Position Sensor (TPS) input less than minimum acceptable voltage.
DRB displays THROTTLE POSITION SENSOR VOLTAGE HIGH. Condition is: Throttle Position Sensor (TPS) input more than maximum acceptable voltage.
Code 25
DRB displays IDLE AIR CONTROL MOTOR CIRCUITS. Condition is: open or shorted condition detected in one or more Idle Air Control (IAC) motor circuits.
Code 27
DRB displays INJECTOR (#1-#8) CONTROL CIRCUIT. Condition is: injector output driver does not respond properly to Powertrain Control Module (PCM) control signal.
Code 31
DRB displays EVAP PURGE SOLENOID CIRCUIT. Condition is: open or shorted condition detected in purge solenoid circuit.
Code 32
DRB displays EGR SOLENOID CIRCUIT. Condition is: open or shorted condition detected in EGR solenoid circuit.
DRB displays EGR SYSTEM FAILURE. Condition is: required change in air/fuel ratio not detected during diagnostic test. Trouble code is only present on models with California emissions packages.
Code 33
DRB displays A/C CLUTCH RELAY CIRCUIT. Condition is: open or shorted condition detected in A/C clutch relay circuit.
Code 34
DRB displays SPEED CONTROL SOLENOID CIRCUITS. Condition is: open or shorted condition detected in speed control vacuum or vent solenoid circuits.
DRB displays SPEED CONTROL SWITCH ALWAYS LOW. Condition is: speed control switch input less than minimum acceptable level.
DRB displays SPEED CONTROL SWITCH ALWAYS HIGH. Condition is: speed control switch input more than minimum acceptable level.
Code 35
DRB displays RADIATOR FAN RELAY CIRCUIT. Condition is: open or shorted condition detected in radiator fan relay circuit.
Code 37
DRB displays TORQUE CONVERTER CLUTCH SOLENOID CIRCUIT. Condition is: open or shorted condition detected in torque converter clutch solenoid circuit.
DRB displays TRANS TEMP SENSOR VOLTAGE TOO LOW. Condition is: voltage low at transmission temperature sensor.
DRB displays TRANS TEMP SENSOR VOLTAGE TOO HIGH. Condition is: voltage high at transmission temperature sensor.
Code 41
DRB displays GENERATOR FIELD NOT SWITCHING PROPERLY. Condition is: open or shorted condition detected in alternator field circuit.
Code 42
DRB displays AUTO SHUTDOWN RELAY CONTROL CIRCUIT. Condition is: open or shorted condition detected in Auto Shutdown (ASD) relay circuit.
DRB displays NO ASD RELAY VOLTAGE SENSE AT PCM. Condition is: Powertrain Control Module (PCM) did not receive message in Auto Shutdown (ASD) relay circuit.
Code 43
DRB displays IGNITION COIL (#1-#5) PRIMARY CIRCUIT. Condition is: peak primary circuit current not achieved with maximum dwell time.
Code 44
DRB displays BATTERY TEMP SENSOR VOLTS OUT OF LIMIT. Condition is: battery temperature sensor volts out of limit.
Code 45
DRB displays OVERDRIVE SOLENOID. Condition is: open or shorted condition detected in overdrive solenoid circuit.
Code 46
DRB displays CHARGING SYSTEM VOLTAGE TOO HIGH. Condition is: battery voltage sense input more than target charging voltage during engine operation.
Code 47
DRB displays CHARGING SYSTEM VOLTAGE TOO LOW. Condition is: battery voltage sense input less than target charging voltage during engine operation.
Code 51
DRB displays O2S STAYS BELOW CENTER (LEAN). Condition is: oxygen sensor input indicates lean air/fuel ratio during engine operation.
Code 52
DRB displays ADDITIVE ADAPTIVE MEMORY AT LEAN LIMIT. Condition is: additive adaptive memory at lean limit.
DRB displays O2S STAYS ABOVE CENTER (RICH). Condition is: oxygen sensor input indicates rich air/fuel ratio during engine operation.
Code 53
DRB displays INTERNAL PCM FAILURE. Condition is: Powertrain Control Module (PCM) detects internal failure.
DRB displays PCM FAILURE SPI COMMUNICATION. Condition is: Powertrain Control Module (PCM) detects internal failure.
Code 54
DRB displays CRANKSHAFT SIGNAL SYNC PICK-UP SIGNAL. Condition is: no fuel sync signal detected during crankshaft rotation.
DRB displays NO CAM SYNC SIGNAL AT PCM. Condition is: open or shorted condition detected in cam sync signal circuit.
Code 55
DRB display will be blank. Completion of trouble code display by MIL light.
Code 62
DRB displays PCM FAILURE SRI MILES NOT STORED. Condition is: Powertrain Control Module (PCM) detects internal failure.
Code 63
DRB displays PCM FAILURE EEPROM WRITE DENIED. Condition is: unsuccessful attempt to write to an EEPROM location by PCM.
SUMMARY
If no hard trouble codes (or only pass codes) are present, driveability symptoms exist or intermittent codes exist, proceed to TESTS W/O CODES - GASOLINE article in the ENGINE PERFORMANCE section article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.