Engine Controls - Tests W/codes - 3.8L: Overview — Dodge Caravan III (1995-2000)

CONNECTOR IDENTIFICATION

Connector	See
A/C Pressure Sensor	5
Brake Switch	6
Camshaft Position Sensor	7
Crankshaft Position Sensor	8
Data Link Connector	9
Downstream Oxygen Sensor	10
EGR Solenoid	11
Engine Coolant Temperature Sensor	12
EVAP Purge Solenoid	13
Fuel Tank Module	14
Idle Air Control Motor	15
Ignition Coil	16
Injector	17
Injector Wiring Harness (Injector Side)	18
Injector Wiring Harness (PCM Side)	19
Knock Sensor	20
Leak Detection Pump	21
MAP Sensor	22
Output Speed Sensor (4-Speed A/T)	23
Park/Neutral Switch (3-Speed A/T)	24
Powertrain Control Module (PCM)	25
Radiator Cooling Fan Relay	26
Speed Control Servo	27
Throttle Position Sensor	28
Torque Converter Clutch Solenoid (3-Speed A/T)	29
Transmission Control Module (4-Speed A/T)	30
Transmission Range Sensor (4-Speed A/T)	31
Upstream Oxygen Sensor	32
Vehicle Speed Sensor (3-Speed A/T)	40

CONNECTOR IDENTIFICATION DIRECTORY

Scheme 161

Terminal	Wire Color	Function
1	Violet/White	5-Volt Supply
2	Black/Light Blue	Sensor Ground
3	Not Used	Not Used
4	Dark Blue	Sensor Signal

A/C PRESSURE SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 162

Terminal	Wire Color	Function
1	White/Pink	Brake Switch Sense
2	Black	Ground
3	Yellow/Red	S/C On/Off Switch Output
4	Dark Blue/Red	S/C Brake Switch Output
5	White/Tan	Brakelight Switch Output
6	Pink/Dark Blue	Fused B+

BRAKE SWITCH CONNECTOR TERMINAL IDENTIFICATION

Scheme 163

Terminal	Wire Color	Function
1	Orange	8-Volt Supply
2	Black/Light Blue	Sensor Ground
3	Tan/Yellow	Sensor Signal

CAMSHAFT POSITION SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 164

Terminal	Wire Color	Function
1	Orange	8-Volt Supply
2	Black/Light Blue	Sensor Ground
3	Gray/Black	Sensor Signal

CRANKSHAFT POSITION SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 165

Terminal	Wire Color	Function
3	Violet/Brown	CCD Bus (+)
4	Black/Light Green	Ground
5	Black/White	Ground
6	Light Green	SCI Receive
7	Pink	SCI Transmit
11	White/Black	CCD Bus (-)
14	Pink/Light Blue	SCI Receive (TCM)
16	Pink	Fused B+

DATA LINK CONNECTOR TERMINAL IDENTIFICATION

Scheme 166

Terminal	Wire Color	Function
1	Black/Tan	Heater Ground
2	Dark Green/Orange	Auto Shutdown Relay Output
3	Black/Light Blue	Sensor Ground
4	Tan/White	Sensor Signal

DOWNSTREAM OXYGEN SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 167

Terminal	Wire Color	Function
1	Gray/Yellow	EGR Solenoid Control
2	White/Black	Fused Ign. Switch Output

EGR SOLENOID CONNECTOR TERMINAL IDENTIFICATION

Scheme 168

Terminal	Wire Color	Function
1	Tan/Black	Sensor Signal
2	Black/Light Blue	Sensor Ground

ENGINE COOLANT TEMP. SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 169

Terminal	Wire Color	Function
1	Pink/Black	EVAP Purge Solenoid Control
2	White/Black	Fused B+

EVAP PURGE SOLENOID CONNECTOR TERMINAL IDENTIFICATION

Scheme 170

Terminal	Wire Color	Function
1	Dark Green/White	Fuel Pump Relay Output
2	Dark Blue	Fuel Level Sensor Signal
3	Not Used	Not Used
4	Black	Ground

FUEL TANK MODULE CONNECTOR TERMINAL IDENTIFICATION

Scheme 171

Terminal	Wire Color	Function
1	Violet/Black	IAC Motor No. 4 Driver
2	Brown/White	IAC Motor No. 3 Driver
3	Yellow/Black	IAC Motor No. 2 Driver
4	Gray/Red	IAC Motor No. 1 Driver

IDLE AIR CONTROL MOTOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 172

Terminal	Wire Color	Function
1	Red/Yellow	Ignition Coil No. 3 Driver
2	Gray	Ignition Coil No. 1 Driver
3	Dark Blue/Tan	Ignition Coil No. 2 Driver
4	Dark Green/Orange	Auto Shutdown Relay Output

IGNITION COIL CONNECTOR TERMINAL IDENTIFICATION

Scheme 173

Terminal	Wire Color	Function
1	Dark Green/Orange	Auto Shutdown Relay Output
2 (1)	White/Dark Blue	Injector No. 1 Driver
2 (1)	Tan	Injector No. 2 Driver
2 (1)	Yellow/White	Injector No. 3 Driver
2 (1)	Light Blue/Brown	Injector No. 4 Driver
2 (1)	Gray	Injector No. 5 Driver
2 (1)	Brown/Dark Blue	Injector No. 6 Driver
(1) Connectors are same for all injectors except wire color at terminal No. 2. Listed are wire colors for specified injector driver at terminal No. 2.

(1)	Connectors are same for all injectors except wire color at terminal No. 2. Listed are wire colors for specified injector driver at terminal No. 2.

INJECTOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 174

Terminal	Wire Color	Function
1	Dark Green/Orange	Auto Shutdown Relay Output
2	Violet/White	5-Volt Supply
3	White/Dark Blue	Injector No. 1 Driver
4	Tan	Injector No. 2 Driver
5	Yellow/White	Injector No. 3 Driver
6	Light Blue/Brown	Injector No. 4 Driver
7	Dark Blue/Tan	Ignition Coil No. 2 Driver
8	Red/Yellow	Ignition Coil No. 3 Driver
9	Gray	Ignition Coil No. 1 Driver
10	Dark Green/Red	MAP Sensor Signal
11	Tan/Black	Coolant Temp. Sensor Signal
12	Gray	Injector No. 5 Driver
13	Brown/Dark Blue	Injector No. 6 Driver
14	Black/Light Blue	Sensor Ground

INJECTOR WIRING HARNESS CONNECTOR (INJECTOR SIDE) TERMINAL ID

Scheme 175

Terminal	Wire Color	Function
1	Dark Green/Orange	Auto Shutdown Relay Output
2	Violet/White	5-Volt Supply
3	White/Dark Blue	Injector No. 1 Driver
4	Tan	Injector No. 2 Driver
5	Yellow/White	Injector No. 3 Driver
6	Light Blue/Brown	Injector No. 4 Driver
7	Dark Blue/Tan	Ignition Coil No. 2 Driver
8	Red/Yellow	Ignition Coil No. 3 Driver
9	Gray	Ignition Coil No. 1 Driver
10	Dark Green/Red	MAP Sensor Signal
11	Tan/Black	Coolant Temp. Sensor Signal
12	Gray	Injector No. 5 Driver
13	Brown/Dark Blue	Injector No. 6 Driver
14	Black/Light Blue	Sensor Ground

INJECTOR WIRING HARNESS CONNECTOR (PCM SIDE) TERMINAL ID

Scheme 176

Terminal	Wire Color	Function
1	Black/Light Blue	Sensor Ground
2	Dark Blue/Light Green	Sensor Signal

KNOCK SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 177

Terminal	Wire Color	Function
1	Yellow/Black	Pump Switch Sense
2	White/Dark Green	Solenoid Control
3	White/Black	Fused Ign. Switch Output
4	Not Used	Not Used

LEAK DETECTION PUMP CONNECTOR TERMINAL IDENTIFICATION

Scheme 178

Terminal	Wire Color	Function
1	Violet/White	5-Volt Supply
2	Black/Light Blue	Sensor Ground
3	Dark Green/Red	Sensor Signal

MAP SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 179

Scheme 179: OUTPUT SPEED SENSOR CONNECTOR TERMINAL ID (4-SPEED A/T)

Terminal	Wire Color	Function
1	Dark Blue/Black	Sensor Ground
2	Light Green/White	Output Speed Sensor Signal

OUTPUT SPEED SENSOR CONNECTOR TERMINAL ID (4-SPEED A/T)

Scheme 180

Scheme 180: PARK/NEUTRAL SWITCH CONNECTOR TERMINAL ID (3-SPEED A/T)

Terminal	Wire Color	Function
1	Violet/Black	Reverse Light Sense
2	Black/White	Park/Neutral Switch Sense
3	White	Fused Ign. Switch Output

PARK/NEUTRAL SWITCH CONNECTOR TERMINAL ID (3-SPEED A/T)

Scheme 181

Terminal No.	Wire Color	Function
2	Red/Yellow	Ign. Coil Driver No.3
3	Dark Blue/Tan	Ign. Coil Driver No. 2
4	Dark Green	Generator Field Driver
5	Yellow/Red	Speed Control Power Supply
6	Dark Green/Orange	Auto Shutdown Relay Output
7	Yellow/White	Injector No. 3 Driver
8	Tan	Starter Relay Control
10	Black/Tan	Ground
11	Gray	Ign. Coil Driver No. 1
13	White/Dark Blue	Injector No. 1 Driver
14	Brown/Dark Blue	Injector No. 6 Driver
15	Gray	Injector No. 5 Driver
16	Light Blue/Brown	Injector No. 4 Driver
17	Tan	Injector No. 2 Driver
20	White/Black	Fused Ign. Switch Output
22	Black/Pink	MIL Driver
24	Dk. Blue/Lt. Green	Knock Sensor Signal
26	Tan/Black	Coolant Temp. Sensor Signal
30	Black/Dark Green	Upstream O2 Sensor Signal
32	Gray/Black	Crank Position Sensor Signal
33	Tan/Yellow	Cam Position Sensor Signal
35	Orange/Dark Blue	TPS Signal
36	Dark Green/Red	MAP Sensor Signal
40	Gray/Yellow	EGR Solenoid Control
41	Red/Light Green	Speed Control Switch Signal
42	Dark Blue	A/C Pressure Switch Sense
43	Black/Light Blue	Sensor Ground
44	Orange	8-Volt Supply
45	Dark Green	A/C Signal
46	Red/White	Fused B+
48	Brown/White	IAC Motor No. 3 Driver
49	Yellow/Black	IAC Motor No. 2 Driver
50	Black/Tan	Ground
51	Tan/White	Downstream O2 Sensor Signal
57	Gray/Red	IAC Motor No. 1 Driver
58	Violet/Black	IAC Motor No. 4 Driver
59	Violet/Brown	CCD Bus (+)
60	White/Black	CCD Bus (-)
61	Violet/White	5-Volt Supply
62	White/Pink	Brake Switch Sense
63 (1)	Yellow/Dark Green	Torque Management Request
64	Dark Blue/Orange	A/C Clutch Relay Control
65	Pink	SCI Transmit
66	White/Orange	Vehicle Speed Sensor Signal
67	Dark Blue/Yellow	Auto Shutdown Relay Control
68	Pink/Black	EVAP Purge Solenoid Control
72	Yellow/Black	Leak Detection Pump Sense
73	Lt. Green/Dk. Blue	Radiator Fan Relay Control
74	Brown	Fuel Pump Relay Control
75	Light Green	SCI Receive
76	Black/White	Park/Neutral Switch Sense
77	White/Dark Green	Leak Detection Pump Control
78	Tan/Red	Speed Control Vacuum
79	N/A	Solenoid Control
80	Light Green/Red	Speed Control Vent
81	N/A	Solenoid Control
(1) Applies to models with 4-speed electronic controlled transaxle.

(1)	Applies to models with 4-speed electronic controlled transaxle.

PCM CONNECTOR TERMINAL IDENTIFICATION

Terminal	Wire Color	Function
1	Black	Ground
2	Light Green/Dark Blue	Rad Fan Relay Control
3	Dark Green	Rad Fan Relay Output
4	Gray	Fused B+

RADIATOR COOLING FAN RELAY CONNECTOR TERMINAL IDENTIFICATION

Terminal	Wire Color	Function
1	Tan/Red	S/C Vacuum Solenoid Control
2	Light Green/Red	S/C Vent Solenoid Control
3	Dark Blue/Red	S/C Brake Switch Output
4	Black	Ground

SPEED CONTROL SERVO CONNECTOR TERMINAL IDENTIFICATION

Scheme 182

Terminal	Wire Color	Function
1	Black/Light Blue	Sensor Ground
2	Orange/Dark Blue	Sensor Signal
3	Violet/White	5-Volt Supply

THROTTLE POSITION SENSOR CONNECTOR TERMINAL IDENTIFICATION

Scheme 183

Scheme 183: TRANSMISSION CONTROL MODULE CONNECTOR TERMINAL ID

Terminal	Wire Color	Function
1	Light Green/Black	TRS T1 Sensor
3	Violet	TRS T3 Sensor
4	White/Black	CCD Bus (-)
5	N/A	Autostick Upshift Switch Sensor
6	Gray/Black	Crankshaft Position Sensor Signal
7	Pink	SCI Transmit
8	Yellow/Red	Ignition Switch Out (Start)
9	Orange/Black	OD Press Switch Sensor
10	Yellow/Dark Green	Torque Management Request Sensor
11	Red/White	Ignition Switch Out (Run/Stop)
12	Orange/Dark Blue	TP Sensor Signal
13	Dark Blue/Black	Speed Sensor Ground
14	Light Green/White	Output Speed Sensor Signal
15	Light Green	Transmission Relay Control
16	Red	Transmission Control Relay Output
17	Red	Transmission Control Relay Output
19	White	2-4 Solenoid Control
20	Light Blue	L-R Solenoid Control
41	Black/White	TRS T41 Sensor
42	Violet/White	TRS T42 Sensor
43	Violet/Brown	CCD Bus (+)
44	N/A	Autostick Downshift Switch Sensor
46	Pink/Light Blue	SCI Receive
47	Yellow/Black	2-4 Pressure Switch Sensor
49	N/A	OD Off Switch Sensor
50	Dark Green	L-R Pressure Switch Sensor
51	Black/Light Blue	Sensor Ground
52	Red/Black	InPut Speed Sensor Signal
53	Black/Yellow	Ground
54	Violet/Light Green	Transmission Temperature Sensor Signal
56	Red	Fused B(+)
57	Black/Red	Ground
58	White/Orange	VSS Signal
59	Pink	UD Solenoid Control
60	Brown	OD Soenoid Control

TRANSMISSION CONTROL MODULE CONNECTOR TERMINAL ID

Scheme 184

Scheme 184: TRANSMISSION RANGE SENSOR CONNECTOR TERMINAL ID (4-SPEED A/T)

Terminal	Wire Color	Function
1	White	Fused Ign. Switch Output
2	Not Used	Not Used
3	Dark Blue/Black	Speed Sensor Ground
4	Violet/Light Green	Trans. Temp. Sensor Signal
5	Black/White	C4 Sense To PCM
6	Violet/Black	Back-Up Lights
7	Light Green/Black	C4 Sense To TCM
8	Violet	C3 Sense To TCM
9	Violet/White	C2 Sense To TCM
10	Black/White	C1 Sense To TCM

TRANSMISSION RANGE SENSOR CONNECTOR TERMINAL ID (4-SPEED A/T)

Terminal	Wire Color	Function
1	Black	Heater Ground
2	Dark Green/Orange	Auto Shutdown Relay Output
3	Black/Light Blue	Sensor Ground
4	Black/Dark Green	Sensor Signal

UPSTREAM OXYGEN SENSOR CONNECTOR TERMINAL IDENTIFICATION

DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION

DRB-III Scan Tool Message	Test No.	Generic Scan Tool Code	MIL Code
5-VOLT SUPPLY OUTPUT TOO LOW	TC-146A	P1496	71
A/C CLUTCH RELAY CIRCUIT	TC-16A	N/A	33
A/C PRESSURE SENSOR VOLTS TOO HIGH	TC-90A	N/A	33
A/C PRESSURE SENSOR VOLTS TOO LOW	TC-91A	N/A	33
AUTO SHUTDOWN RELAY CONTROL CIRCUIT	TC-10A	N/A	42
BAROMETRIC PRESSURE OUT OF RANGE	TC-60A	P0106	61
BATTERY TEMP SENSOR VOLTAGE TOO HIGH	TC-153A	P1492	44
BATTERY TEMP SENSOR VOLTAGE TOO LOW	TC-153A	P1493	44
BRAKE SWITCH STUCK PRESSED OR RELEASED	TC-152A	P0703	65
CATALYTIC CONVERTER EFFICIENCY FAILURE	TC-112A	P0420	64
CHARGING SYSTEM VOLTAGE TOO HIGH	TC-6A	N/A	46
CHARGING SYSTEM VOLTAGE TOO LOW	TC-5A	N/A	47
CLOSED LOOP TEMPERATURE NOT REACHED	TC-128A	P0125	17
CYLINDER #1 MISFIRE	TC-107A	P0301	43
CYLINDER #2 MISFIRE	TC-107A	P0302	43
CYLINDER #3 MISFIRE	TC-107A	P0303	43
CYLINDER #4 MISFIRE	TC-107A	P0304	43
CYLINDER #5 MISFIRE	TC-107A	P0305	43
CYLINDER #6 MISFIRE	TC-107A	P0306	43
DOWNSTREAM O2 SENSOR HEATER FAILURE	TC-105A	P0141	21
DOWNSTREAM O2 SENSOR SHORTED TO VOLTAGE	TC-126A	P0138	21
DOWNSTREAM O2 SENSOR STAYS AT CENTER	TC-129A	P0140	21
DOWNSTREAM O2S VOLTAGE SHORTED TO GROUND	TC-156A	P0137	21
EATX CONTROLLER DTC PRESENT	(1)	P0700	45
ECT SENSOR VOLTAGE TOO HIGH	TC-31A TEST TC-31A - ENGINE COOLANT TEMP. (ECT) SENSOR VOLTAGE TOO HIGH	P0118	22
ECT SENSOR VOLTAGE TOO LOW	TC-30A	P0117	22
EGR SOLENOID CIRCUIT	TC-17A	P0403	32
EGR SYSTEM FAILURE	TC-46A	P0401	32
ENGINE IS COLD TOO LONG	(2)	N/A	17
EVAP PURGE FLOW MONITOR FAILURE	TC-113A	P0441	31
EVAP PURGE SOLENOID CIRCUIT	TC-18A	P0443	31
EVAP SYSTEM GROSS LEAK	TC-161A	P0455	31
EVAP LEAK MONITOR PINCHED HOSE	TC-187A	P1486	31
EVAP SYSTEM SMALL LEAK	TC-160A	P0442	31
FUEL LEVEL SENDING UNIT VOLTS TOO HIGH	(3)	N/A	42
FUEL LEVEL SENDING UNIT VOLTS TOO LOW	(3)	N/A	42
FUEL LEVEL SENDING UNIT NO CHANGE OVER MILES	(3)	N/A	42
FUEL PUMP RELAY CONTROL CIRCUIT	TC-101A	N/A	42
FUEL SYSTEM LEAN	TC-119A	P0171	51
FUEL SYSTEM RICH	TC-118A	P0172	52
GENERATOR FIELD NOT SWITCHING PROPERLY	TC-11A	N/A	41
IDLE AIR CONTROL MOTOR CIRCUITS	TC-25A	P0505	25
IGNITION COIL #1 PRIMARY CIRCUIT	TC-43A	P0351	43
IGNITION COIL #2 PRIMARY CIRCUIT	TC-43A	P0352	43
IGNITION COIL #3 PRIMARY CIRCUIT	TC-43A	P0353	43
INJECTOR #1 CONTROL CIRCUIT	TC-21A	P0201	27
INJECTOR #2 CONTROL CIRCUIT	TC-21A	P0202	27
INJECTOR #3 CONTROL CIRCUIT	TC-21A	P0203	27
INJECTOR #4 CONTROL CIRCUIT	TC-21A	P0204	27
INJECTOR #5 CONTROL CIRCUIT	TC-21A	P0205	27
INJECTOR #6 CONTROL CIRCUIT	TC-21A	P0206	27
INTERMITTENT LOSS OF CMP OR CKP	TC-157A	P1391	11
INTERNAL CONTROLLER FAILURE	(4)	P0601	53
KNOCK SENSOR CIRCUIT	TC-59A	N/A	16
LEAK DETECTION PUMP PRESSURE SWITCH	TC-184A	P1494	31
LEAK DETECTION PUMP SOLENOID CIRCUIT	TC-183A	P1495	31
MAP SENSOR VOLTAGE TOO HIGH	TC-37A	P0108	14
MAP SENSOR VOLTAGE TOO LOW	TC-36A	P0107	14
MIS-FIRE ADAPTIVE NUMERATOR AT LIMIT	TC-186A	P1398	11
MULTIPLE CYLINDER MISFIRE	TC-106A	P0300	43
NO ASD RELAY OUTPUT VOLTAGE AT PCM	TC-44A	N/A	42
NO CAM SIGNAL AT PCM	TC-1A	P0340	54
NO CCD MESSAGE FROM BODY CONTROL MODULE	TC-97A	P1695	66
NO CCD MESSAGES FROM TCM	TC-96A	P1698	66
NO CHANGE IN MAP FROM START TO RUN	TC-39A	P1297	13
NO CRANK REFERENCE SIGNAL AT PCM	TC-40A	N/A	11
NO VEHICLE SPEED SENSOR SIGNAL	TC-35A	P0500	15
PARK/NEUTRAL SWITCH FAILURE	TC-114A	P1899	37
PCM FAILURE EEPROM WRITE DENIED	TC-48A	P1696	63
PCM FAILURE SPI COMMUNICATIONS	(4)	P0600	53
PCM FAILURE SRI MILE NOT STORED	TC-48A	P1697	62
RAD FAN CONTROL RELAY CIRCUIT	TC-14A	P1491	35
SLOW UPSTREAM O2 DURING CATALYST MONITOR	TC-192A	P0133	21
SPEED CONTROL SOLENOID CIRCUITS	TC-15A	N/A	34
TARGET IDLE NOT REACHED	TC-138A	P1294	25
THROTTLE POSITION SENSOR VOLTAGE HIGH	TC-27A	P0123	24
THROTTLE POSITION SENSOR VOLTAGE LOW	TC-26A	P0122	24
TPS VOLTAGE DOES NOT AGREE WITH MAP	TC-132A	P0121	24
UPSTREAM O2 SENSOR HEATER FAILURE	TC-103A	P0135	21
UPSTREAM O2 SENSOR SHORTED TO VOLTAGE	TC-62A	P0132	21
UPSTREAM O2 SENSOR SLOW RESPONSE	TC-102A	P0133	21
UPSTREAM O2 SENSOR STAYS AT CENTER	TC-32A	P0134	21
UPSTREAM O2S VOLTAGE SHORTED TO GROUND	TC-155A	P0131	21
(1) Refer to appropriate AUTOMATIC TRANSAXLE article in appropriate section for diagnosis of electronic controlled transaxle. (2) Check cooling system and thermostat ifengine coolant temperature does not reach 176°F (80°C) after driving 20 minutes. (3) See appropriate BODY CONTROL COMPUTER TESTS article in ACCESSORIES & EQUIPMENT section. (4) Replace Powertrain Control Module (PCM). Perform TEST VER-2A.

(1)	Refer to appropriate AUTOMATIC TRANSAXLE article in appropriate section for diagnosis of electronic controlled transaxle.

(2)	Check cooling system and thermostat ifengine coolant temperature does not reach 176°F (80°C) after driving 20 minutes.

(3)	See appropriate BODY CONTROL COMPUTER TESTS article in ACCESSORIES & EQUIPMENT section.

(4)	Replace Powertrain Control Module (PCM). Perform TEST VER-2A.

DTC MESSAGES & CODES

TEST NTC-4A - CHECKING COOLANT SENSOR CALIBRATION & RADIATOR FAN OPERATION

Note. Perform NTC-1A or NTC-3A before proceeding. Following test procedure is invalid if thermostat is stuck open, closed or removed.

Check thermostat operation. If thermostat operates correctly, go to next step. If thermostat does not operate correctly, replace thermostat. Perform TEST VER-2A.
Ensure ignition is on with engine off. Ensure engine coolant temperature is less than 160°F (71°C).
Using scan tool, read Engine Coolant Temperature (ECT) sensor value. Using temperature probe, check temperature on cylinder block, near engine coolant temperature sensor. Engine coolant temperature sensor is located near thermostat housing and contains a Black/Light Blue wire and Tan/Black wire in the connector.
If ECT sensor value on scan tool is not within 15°F (-9°C) of temperature reading on temperature probe, replace engine coolant temperature sensor. Perform TEST VER-2A. If ECT sensor value on scan tool is within 15°F (-9°C) of temperature reading on temperature probe, go to next step.
Start engine and warm engine until engine coolant temperature is greater than 180°F (82°C). Using temperature probe, check temperature on cylinder block, near engine coolant temperature sensor. Compare ECT sensor value on scan tool with temperature reading on temperature probe.
If ECT sensor value on scan tool does not stay within 15°F (-9°C) of temperature reading on temperature probe at all times, replace engine coolant temperature sensor. Perform TEST VER-2A. If ECT sensor value on scan tool stays within 15°F (-9°C) of temperature reading on temperature probe at all times, go to next step.
Operate engine until radiator fan operates or engine coolant temperature reaches 220°F (104°C). If cooling fan does not operate, repair cooling fan as necessary. See appropriate SPECIFICATIONS & ELECTRIC COOLING FANS article in the ENGINE COOLING section. If cooling fan operates, engine coolant temperature sensor and radiator fan are operating properly. Test is complete.

See also:
• WIRING DIAGRAMS - 3.8L
• ADJUSTMENTS - 3.8L

Engine Controls - Tests W/codes - 3.8L: Overview Dodge Caravan III