NOTE: Both the Crankshaft Position Sensor and Camshaft Position Sensor are abbreviated CPS. Don't get them confused.
In the tables below I use CamPS and CrankPS, these are not normal abbreviations.

Side note: It's a work in progress.  Image names will probably remain the same but the page may be broken apart or reorganized in the future.  Link directly at your own risk.  I would prefer you use the main URL http://revbeergoggles.com/


QUICK LINK: SENSORS/SENDERS : FIRING ORDER : FUEL SYSTEM : ENGINE RELAY AND FUSE BANK : ABS COMPUTER :

DIAGNOSTICS (X indicates the sensor is part of the loop)

(note: this table is for the 93 ZJ but should be applicable for other years)
 

Start
up		 Warm
up		 Idle Cruise Accel Hard
Decel		 Wide
Open		 Sensor
Battery volt X X X X X X X  Integral to the Computer
Coolant temp
ohm table
Gauge		 X X X X X X X Located by the upper radiator hose on the engine.
CrankPS

More Information

 X X X X   X X  Located 11 o'clock on the 
transmission bell housing
MAT
ohm table		 X X X X   X X Next to the last connector on the intake rail.
MAP X X X X   X X Located on the firewall just back of the MAT sensor.
TPS X X X X X X X Located on the aft side of the Throttle Body.
CamPS   X X X   X X Located in the distributor. Requries removal of distributor to replace.
AC Signal   X X X   X   Combination of 
AC low pressure switch and 
AC control signal from data bus.
Neutral Sig   X X     X    From Tranny
O2     X X   X   Located on the downpipe just below the exhaust header.

 


Other sensors/senders and test data. (see also above) TOP
 
SENSOR IMAGE
Location & Diagnostics
A/C High Pressure Switch Located on the compressor output side Located on the compressor output side.

DO NOT REMOVE UNIT WITHOUT 
CONSULTING SERVICE MANUAL!
A/C Low Pressure Switch Located on the accumulator. Located on the accumulator.

DO NOT REMOVE UNIT WITHOUT 
CONSULTING SERVICE MANUAL!


The sensor is screwed into a fitting on the accumulator. This fitting has a long travel schrader valve to allow sensor removal without releasing coolant.
Brake travel sensor Located on the booster case. Located on the booster case.
Coolant Fluid Level Located on the coolant fluid overflow bottle. Located on the coolant fluid overflow bottle.
Coolant Temperature

Gauge

 Located by the upper radiator hose on the engine. Located by upper radiator hose.

Coolant/Mat resistance table
ohm table
Crankshaft Position Sensor

More Information
Seems there are two types floating about out there. 
The one Jeep sent me initially was not the one my ZJ uses.
Manifold Air Pressure (MAP) Located on the firewall just back of the MAT sensor. Located on firewall aft of intake rail.

Looking at sensor (as in picture)
(5V, Output, Ground)
 Ignition ON Engine OFF = 4 - 5V
 Ignition ON Engine ON = 1.9 - 3.5V
Manifold Air Temp (MAT) Located on the aft side of the Throttle Body. Located on the intake plenum second from firewall

Coolant/Mat resistance table
ohm table
Oil Level Located on the passenger side of oil pan. Located on the passenger side of oil pan.

No data, presumed dry/pressure contact.
Oil Pressure

Gauge

 Located forward of the oil filter. Located forward of the oil filter.

 0 psi = 1 Ohm
40 psi = 32.5 Ohm
80 psi = 87 Ohm
Speed sensor Located on the transfer case output shaft. Located on the transfer case output shaft.
Washer Fluid Level Located on the washer fluid reservoir bottle. Located on the washer fluid reservoir bottle.

FIRING ORDER TOP
 
Firing Order The ignition Coil
Wire Route

FUEL SYSTEMTOP
 
Fuel Rail Pressure Tap.  Can use a standard R-12 low-side gauge to read.

Normal is 214 kPa / 31 Psi
Fuel Pressure Regulator.  If the vacuum line falls off your pressure will be too high 
and your engine will have all sorts of problems.

Line disconnected fuel rail pressure is 269-283 kPa / 39-41 Psi
Fuel filter.
NAPA Fuel filter: Part# FIL3316 $13.29
Return line pinched*:  75psi within 2 seconds
* Don't pinch hoses for longer than 5 seconds, that would be bad for your fuel pump.

ENGINE FUSE AND RELAY BANK TOP
 
Engine Fuse and Relay Bank
Detail of fuse/relay

ABS COMPUTER TOP
 

SENSOR RESISTANCE - COOLANT TEMP SENSOR/MAT SENSOR* TOP
 
TEMPERATURE RESISTANCE
C F MIN MAX
-40
-20
-10
0
10
20
25
30
40
50
60
70
80
90
100
110
120		 -40
-4
14
32
50
68
77
86
104
122
140
158
176
194
212
230
248		 291,490
85,850
49,250
29,330
17,990
11,370
9,120
7,370
4,900
3,330
2,310
1,630
1,170
860
640
480
370		 381,710
108,390
61,430
35,990
21,810
13,610
10,880
8,750
5,750
3,880
2,670
1,870
1,340
970
720
540
410
* note: This differs from the section in the service manual that talks about the gauge and what it reads.  Assuming the gauge is not damaged (an unlikely event) this table should be used.

TOP


CRANKSHAFT POSITION SENSOR - CONNECTOR AND DETAILS:  TOP
 
 
 
Sensor
A little closer
Plug located on Passenger side of engine by dipstick tube.

 
The part they sent (not the right one) The part I finally got (the right one)
PN 04638128 $53.06
Sensor
Connector
Assembly		 PN 56027280 $72.00
Sensor
Connector
More detail

TOP
 
 

copyleft 2002, DougW
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