Engine Controls - Tests W/codes: Overview

CONNECTOR IDENTIFICATION

Note. Circuit location may vary on some connectors.

Connector	Figure
A/C Compressor Relay	(Scheme 4)
Auto Shutdown (ASD) Relay	(Scheme 5)
Battery Temperature Sensor	(Scheme 6)
Brakelight Switch	(Scheme 7)
Camshaft Position (CMP) Sensor	(Scheme 8)
Clockspring 2-Pin Speed Control Connector	(Scheme 9)
Clockspring 4-Pin Speed Control Connector	(Scheme 10)
Crankshaft Position (CKP) Sensor	(Scheme 11)
Downstream Oxygen Sensor (O2S - Harness Side)	(Scheme 12)
Engine Coolant Temperature (ECT) Sensor	(Scheme 13)
Evaporative Solenoid	(Scheme 14)
Exhaust Gas Recirculation (EGR) Solenoid	(Scheme 15)
Fuel Pump Motor	(Scheme 16)
Fuel Pump Relay	(Scheme 17)
Generator Field	(Scheme 18)
Idle Air Control (IAC) Motor	(Scheme 19)
Ignition Coil	(Scheme 20)
Injector	(Scheme 21)
Intake Air Temperature/Manifold Absolute Pressure (IAT/MAP)	(Scheme 22)
Knock Sensor	(Scheme 23)
Park/Neutral Position Switch	(Scheme 24)
Powertrain Control Module (PCM)	(Scheme 25)
Radiator Fan Relay	(Scheme 26)
Speed Control Servo	(Scheme 27)
Throttle Position (TP) Sensor	(Scheme 28)
Torque Converter Clutch (TCC) Solenoid	(Scheme 29)
Transmission Range Sensor	(Scheme 30)
Upstream Oxygen Sensor (O2S - Harness Side)	(Scheme 31)
Vehicle Speed Sensor (VSS)	(Scheme 32)
16-Pin Data Link Connector (DLC)	(Scheme 33)

CONNECTOR IDENTIFICATION DIRECTORY

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION

Note. Some Diagnostic Trouble Codes (DTCs) have more than one meaning. Malfunction Indicator Light (MIL) is unable to distinguish between different failures. As an example, there are 4 different failures possible for the oxygen sensor (O2S) system, MIL can only identify an O2S failure by flashing a DTC 21. MIL is capable of displaying all possible system failures.

Note. A scan tool may not be able to identify all possible Diagnostic Trouble Codes (DTCs). As an example, a scan tool may not be able to identify or display a DTC for a malfunctioning A/C clutch relay circuit. There are 21 DTCs which a scan tool cannot identify. The Malfunction Indicator Light (MIL) must be used to identify these malfunctions.

Scan Tool Message	Scan Tool	MIL Code	Test No.
5-VOLT SUPPLY OUTPUT TOO LOW	P1496	71	TC-146A
A/C CLUTCH RELAY CIRCUIT	N/A	33	TC-16A
AUTO SHUTDOWN RELAY CONTROL CIRCUIT	N/A	42	TC-10A
BATTERY TEMP SENSOR VOLTAGE TOO HIGH	P1492	44	TC-153A
BATTERY TEMP SENSOR VOLTAGE TOO LOW	P1493	44	TC-153A
BRAKE SWITCH SENSE CIRCUIT	P0703	65	TC-152A
CATALYTIC CONVERTER EFFICIENCY FAILURE	P0420	(1) 64	TC-112A
CHARGING SYSTEM VOLTAGE TOO HIGH	N/A	46	TC-6A
CHARGING SYSTEM VOLTAGE TOO LOW	N/A	47	TC-5A
CLOSED LOOP TEMPERATURE NOT REACHED	P0125	17	TC-128A
CYLINDER #1 MISFIRE	P0301	43	TC-107A
CYLINDER #2 MISFIRE	P0302	43	TC-107A
CYLINDER #3 MISFIRE	P0303	43	TC-107A
CYLINDER #4 MISFIRE	P0304	43	TC-107A
CYLINDER #5 MISFIRE	P0305	43	TC-107A
CYLINDER #6 MISFIRE	P0306	43	TC-107A
DOWNSTREAM O2 SENSOR HEATER FAILURE	P0141	21	TC-105A
DOWNSTREAM O2 SENSOR SHORTED TO VOLTAGE	P0138	21	TC-126A
DOWNSTREAM O2 SENSOR STAYS AT CENTER	P0140	21	TC-129A
DOWNSTREAM O2S VOLTAGE SHORTED TO GROUND	P0137	21	TC-156A
EATX CONTROLLER DTC PRESENT	P0700	45	(2)
ECT SENSOR VOLTAGE TOO HIGH	P0118	22	TC-31A
ECT SENSOR VOLTAGE TOO LOW	P0117	22	TC-30A
EGR SOLENOID CIRCUIT	P0403	32	TC-17A
EGR SYSTEM FAILURE	P0401	32	TC-46A
ENGINE IS COLD TOO LONG	N/A	17	(3)
EVAP PURGE FLOW MONITOR FAILURE	P0441	31	TC-113A
EVAP PURGE SOLENOID CIRCUIT	P0443	31	TC-18A
FUEL LEVEL SENDING UNIT VOLTS TOO HIGH	N/A	42	(4)
FUEL LEVEL SENDING UNIT VOLTS TOO LOW	N/A	42	(5)
FUEL LEVEL SENDING UNIT NO CHANGE OVER MILES	N/A	42	(6)
FUEL PUMP RELAY CONTROL CIRCUIT	N/A	42	TC-101A
FUEL SYSTEM LEAN	P0171	51	TC-119A
FUEL SYSTEM RICH	P0172	52	TC-118A
GENERATOR FIELD NOT SWITCHING PROPERLY	N/A	41	TC-11A
HIGH SPEED FAN CTRL RELAY CIRCUIT	P1489	35	TC-93A
IDLE AIR CONTROL MOTOR CIRCUITS	P0505	25	TC-25A
IGNITION COIL #1 PRIMARY CIRCUIT	P0351	43	TC-43A
IGNITION COIL #2 PRIMARY CIRCUIT	P0352	43	TC-42A
IGNITION COIL #3 PRIMARY CIRCUIT	P0353	43	TC-41A
INJECTOR #1 CONTROL CIRCUIT	P0201	27	TC-21A
INJECTOR #2 CONTROL CIRCUIT	P0202	27	TC-21A
INJECTOR #3 CONTROL CIRCUIT	P0203	27	TC-21A
INJECTOR #4 CONTROL CIRCUIT	P0204	27	TC-21A
INJECTOR #5 CONTROL CIRCUIT	P0205	27	TC-21A
INJECTOR #6 CONTROL CIRCUIT	P0206	27	TC-21A
INTAKE AIR TEMP SENSOR VOLTAGE HIGH	P0113	23	TC-58A
INTAKE AIR TEMP SENSOR VOLTAGE LOW	P0112	23	TC-57A
INTERMITTENT LOSS OF CMP OR CKP	P1391	11	TC-157A
INTERNAL CONTROLLER FAILURE	P0601	53	(7)
KNOCK SENSOR #2 CIRCUIT	N/A	16	TC-83A
KNOCK SENSOR CIRCUIT	N/A	16	TC-59A
LEAK DETECTION PUMP SWITCH OR MECHANICAL FAULT	P1494	31	TC-184A
LEAK DETECTION PUMP SOLENOID CIRCUIT	P1495	31	TC-183A
O2S SENSOR SHORTED TO VOLTAGE	P0132	21	TC-62A
O2S SENSOR STAYS AT CENTER	P0134	21	TC-32A
UPSTREAM O2 SENSOR HEATER FAILURE	P0135	21	TC-103A
UPSTREAM O2 SENSOR SLOW RESPONSE	P0133	21	TC-102A
LOW SPEED FAN CTRL RELAY CIRCUIT	P1490	35	TC-92A
MANIFOLD TUNE VALVE SOLENOID CIRCUIT	P1289	65	TC-88A
MAP SENSOR VOLTAGE TOO HIGH	P0108	14	TC-37A
MAP SENSOR VOLTAGE TOO LOW	P0107	14	TC-36A
MIS-FIRE ADAPTIVE NUMERATOR AT LIMIT	P1398	11	TC-186A
MULTIPLE CYLINDER MISFIRE	P0300	43	TC-106A
NO 5 VOLTS TO MAP SENSOR	P1296	14	TC-135A
NO ASD RELAY OUTPUT VOLTAGE AT PCM	N/A	42	TC-44A
NO CAM SIGNAL AT PCM	P0340	54	TC-1A
NO CCD MESSAGE FROM BODY CONTROL MODULE	N/A	66	TC-97A
NO CCD MESSAGES FROM TCM	P1698	66	TC-96A
NO CHANGE IN MAP FROM START TO RUN	P1297	13	TC-39A
NO CRANK REFERENCE SIGNAL AT PCM	N/A	11	TC-40A
P/N SWITCH STUCK IN PARK OR IN GEAR	P1899	37	TC-114A
PCM FAILURE SPI COMMUNICATIONS	P0600	53	(7)
PCM FAILURE SRI MILE NOT STORED	P1697	62	TC-48A
POWER STEERING SWITCH FAILURE	P0551	65	TC-115A
RIGHT BANK CATALYST EFFICIENCY FAILURE	P0432	72	TC-180A
SPEED CONTROL POWER RELAY CIRCUIT	N/A	77	TC-15A
SPEED CONTROL SOLENOID CIRCUITS	N/A	34	TC-15A
SPEED CONTROL SWITCH ALWAYS HIGH	N/A	34	TC-86A
SPEED CONTROL SWITCH ALWAYS LOW	N/A	34	TC-87A
TARGET IDLE NOT REACHED	P1294	25	TC-138A
THROTTLE POSITION SENSOR VOLTAGE HIGH	P0123	24	TC-27A
THROTTLE POSITION SENSOR VOLTAGE LOW	P0122	24	TC-26A
TIMING BELT SKIPPED 1 TOOTH OR MORE	P1390	11	TC-133A
TORQ CONV CLU, NO RPM DROP AT LOCKUP	P0740	37	TC-148A
TORQUE CONVERTER CLUTCH SOLENOID/TRANS RELAY CKTS	P0743	37	TC-12A
TPS VOLTAGE DOES NOT AGREE WITH MAP	P0121	24	TC-132A
UPSTREAM O2S VOLTAGE SHORTED TO GROUND	P0131	21	TC-155A
UPSTREAM O2 SENSOR HEATER FAILURE	P0135	21	TC-103A
UPSTREAM O2 SENSOR SHORTED TO VOLTAGE	P0132	21	TC-62A
UPSTREAM O2 SENSOR SLOW RESPONSE	P0133	21	TC-102A
VACUUM LEAK FOUND (IAC FULLY SEATED)	P1299	25	TC-145A
(1) MIL may also display Code 72 in addition to code 64. (2) Refer to appropriate TRANSAXLE article for diagnosis of electronic controlled transaxle. (3) Check cooling system and thermostat if engine coolant temperature does not rreach 176°F (80°C) after driving 20 minutes. (4) Refer to TEST TC-150A . (5) Refer to TEST TC-149A . (6) Refer to TEST TC-151A . (7) Replace Powertrain Control Module (PCM). Perform test VER-2A.

(1)	MIL may also display Code 72 in addition to code 64.

(2)	Refer to appropriate TRANSAXLE article for diagnosis of electronic controlled transaxle.

(3)	Check cooling system and thermostat if engine coolant temperature does not rreach 176°F (80°C) after driving 20 minutes.

(4)	Refer to TEST TC-150A .

(5)	Refer to TEST TC-149A .

(6)	Refer to TEST TC-151A .

(7)	Replace Powertrain Control Module (PCM). Perform test VER-2A.

DTC MESSAGES & CODES

TEST NS-7A - CHECKING IDLE AIR CONTROL MOTOR OPERATION

Note. Perform TEST NS-2A before proceeding.

Hold throttle 1/4 depressed and attempt to start engine. If engine started and stayed running, go to next step. If engine did not start and stay running, go to TEST NS-8A.
Release throttle and turn ignition off. Disconnect Idle Air Control (IAC) motor connector. Connect IAC motor connector to a known functional IAC motor. Turn ignition on. Using scan tool, actuate IAC motor. Observe tip of IAC motor. Go to next step.
If IAC motor tip is moving in and out, replace original IAC motor. Perform TEST VER-1A. If IAC motor did not move in and out, check for other related IAC motor trouble codes. If other related IAC motor related trouble codes are present, repair as necessary. If no other related IAC trouble codes are present, replace Powertrain Control Module (PCM). Perform TEST VER-1A.

Engine Controls - Tests W/codes: Overview Dodge Neon I