DODGE CARAVAN WIRING DIAGRAM ERRORS

DODGE CARAVAN WIRING DIAGRAM ERRORS

In Bad design 94 Caravan 3.3L engine installation I describe sloppy design of the installation of accessories, wiring bundles, and plumbing to the engine. That adds substantial cost to operation of the vehicle.

Then there’s the wiring diagrams and service manuals, which use different terms for the same thing even within the wiring diagrams. (E.G. contact 20 of the ECM is variously called “voltage regulator” and “GEN” (being the low side of the alternator’s commutator, by which the ECM varies field current to maintain voltage). Contact 57 is variously “inj sense” and “voltage sense”, a voltage off of the ignition switch that is probably used both as feedback of alternator output to the field current varying function, and to vary injector pulse width if running off the battery only thus voltage is lower.)

And pinouts in Chrysler's wiring diagrams, are they looking at the sensor they are provided for or looking at the harness side of connectors? Probably the harness side, but be cautious, it seems Chrysler people got confused on occassion.

And they have errors:

- diagram AS-HK 149 and 150 Power Distribution Centre lists cavity 22 twice, once in place of cavity 21 which is wire F15 20DB Power for Coil, omits cavities 153 & 154 despite being in illustration and cavity 153 referred to in AS-HK 43 Fuel Injection 3.3 & 3.8L, lists cavity 30 as INJ SENSE when it is actually both “voltage sense” input to ECM and the power feed to coil and injector commons (terminology is confusing).

- the illustration on diagram AS-HK 156 PCM 60-way Connector 3.3 & 3.8L mislabels ECM contacts 41 through 60 as 21 through 40 (which are actually in the center row) and omits the 41 through 60 label. As well, the illustration does not show orientation adequately, page 14-102 (14-107 for 1993) which I believe to be correct is better as it shows more projections and correct shape of the bulge which is on top. (There is no difference between what Chrysler calls long and short tabs, keying is actually by the long narrow keys at the bottom corners, and there is the projection of the harness housing on top of the connector as shown on 14-102 though that is not fully definitive as it can in theory be separated from the connector body. The shape of the projection shown on 14-102 is correct for the harness side of the connection, AS-HK 156 is doubly wrong, shape and location.)
- the empty socket positions on page 14-107 of 1993 manual do not match my 1993 vehicle (30 is empty not 32, 35 not 36, and 37 is not empty). I do not trust those diagrams, which are esssential to checking PCM circuits.

- same problems on AS-HK 163 TCM 60-way Connector
- the incorrect shape of connector is in the illustrations of the 1993 IPC Figure 8-7250, along with incorrect angle of the inlet duct (it it is uphill into the PCM on Caravans). Along with botched drawing of the connector main part, there is no lip at botton right.
- terminology "terminal side" is obscure, clearer would be "harness side".

- diagram AS-HK 43 Fuel Injection 3.3 & 3.8L refers to companion sheet 42 for wire A142 18DG/OR to the “fuel rail”, correct reference is companion sheet 41 to which it feeds power to injector common wire and other places. The same error is on sheet 13 Charging System

- diagram AS-HK 6 Power Distribution Center depiction of connections to ASD and fuel pump relay is wrong, contact 23 of FPR and 31 of ASDR have to be connected only to ECM contact 51. As well, it shows two relay coils in series – rarely done (and that circuit goes nowhere – power on both ends of the coils), and has an incorrect incorrect wire number on contact 30 (should be A142). (Putting a wire K51 from ASD-31 to the PCM-51 note, and adding the correct note for wire A14 to ASD-32 would correct some of the errors.)

- AS-HK 46 Fuel Injection 3.3 & 3.8L incorrectly shows wire A142 at O2 sensor, on the other side of the connector and on other diagrams the wire is A141 (switched power out of the fuel pump relay to the O2 sensor heater).

- There is confusion about contact arrangement for the ground and voltage reference of sensors. Diagram AS-HK 45 shows that contact 1 of the TPS sensor is the voltage reference whereas Test TC-8A of the Powertrain Diagnostic manual shows that contact 1 is ground. Perhaps someone got turned around – looking at sensor connector rather than looking at harness connector (the PD manual explicity shows the harness, the SM only illustrates a few connectors and does not specify the view).

- The Powertrain Diagnostic manual says the cam and crankshaft position sensor reference voltage is 8v, the service manual says 9v.

- diagram AS-HK 41 Fuel Injection 3.3 & 3.8L does not show the contact arrangement of the connector to the ignition coil, whereas it does show a disconnect between the coil and PCM. (Would be nice if also showed internal circuit of the coil.)

- diagram AS-HK 42 Fuel Injection 3.3 & 3.8L also has a “fuel rail” annotation but that is probably a common ground (K4-4 splice) used by several sensors but not by injectors which are individually switched to ground by the ECM. Perhaps “fuel rail” refers to the location of one instance of each of splices K4 and A142 located in harnesses that run near the two fuel rails, I see the term on another splice number as well. (Splices are buried in harnesses of course – hey! it could be worse, like the diode in the headlamp door circuit of some 1967 Camaros with RS trim option, buried in a harness running below the inner lip of a fender on some cars, under the dash on others, not shown on factory wiring diagrams.)

- diagram AS-HK 42 Fuel Injection 3.3 & 3.8L has an incorrect illustration of internals of the camshaft position sensor. The diagram shows a potentiometer which is not correct given it senses metal or absence of metal (slots). If it were a potentiometer the wiper would be connected to the ECM, rather than the connection shown.

- diagram AS-HK 163 Transmission Control Module connector does not show crankshaft sensor input to contact 6 as shown on diagram AS-HK 52. Appears was not revised to cover distributorless ignition system. It does show TPS to contact 12 as per AS-HK 54.

- while sharing the Crankshaft and TP sensor signals with the ECM, it appears to use a different signal ground refernce (ultimately all go to battery negative/engine ground anyway, but more circuitous path is a risk of noise/offset).

- diagram AS-HK 42 depiction of contact function of camshaft sensor and AS-HK 47 of crankshaft sensor appear to be reversed from the PDPM. The vehicle wiring has the voltage from ECM-7 connected to the right contact (right side of harness end view if latch positioned up).

- unclear which way inline connectors like the one on AS-HK 42 Fuel Injection 3.3 & 3.8L are flipped apart, takes mental gymnastics to follow wire through. Is the connector flipped along the long edges or short edges or whichever face the other? E.G. AS-HK 47 has the same type of connector halves facing three different ways in the three different instances, “flip on edges facing each other” fits that diagram’s wire numbering. (Is oriented to point-point checks to someone’s instructions, not verification of circuit for troubleshooting given that some errors in diagrams incorrectly change the wire number across a connection.)

- as well, the external projections on illustration of those inline connectors don’t make sense. These connectors have a latch going over a single tab, thus one half should show a tab and the other half a representation of the latch.

- also would be helpful to annotate more splices with their function, such as “IGN ON power” or “GND”.

- text page 8A-25 omits 3.8L engine from table of alternator use, and is not clear on which way is up in identifying pin 20 of ECM harness connector (connector would normally be seen upside down from what is shown, due to the way the wiring will normally bend when pulling connector away from ECM).

- diagram AS-HK 14, the wiring diagram for the alternator on 1994 and like 3.3/3.8L engines shows three stator windings whereas my vehicle has four (less ripple), I don't know where the capacity is that the diagram shows.

- The Index to the component identification section of 8W Wiring Diagrams is mixed up. There should be two columns in each half, one for Figure number (which is there) and one for page (or get rid of the page word above each figure column).

- I cannot find the camshaft sensor in those figures. (It is at the right end of the engine.)

- the index to the AS-CNG diagrams lists “fuel pump”, the referenced page makes more sense (showing shutoff and quantity devices – natural gas does not need a pump, it is stored under pressure so is self-moving, the challenge is to keep it contained).

- As well, it appears that there are two versions of wiring diagrams covering the 3.3L engine, laid out somewhat differently. Why?

These are easy mistakes to make but should be caught by checking.
Checkers should think through what they are reading, and trace circuits, so they catch logical errors. AS-HK 6 is an especially bad case, with multiple instances of illogical connection. Checkers must understand electricity and use that knowledge.

The errors were carried for at least two model years, despite additions of engine displacement and functions to the diagrams.
Perhaps there is a correction list somewhere though it would be long.
Mistakes really slow the user, costing them money. It is important to know all the connections of a particular wire – for example, to test continuity of the fuel pump from the relay socket you must first disconnect the O2 sensor heater.

Apparently current production Caravans are far more reliable than the first two "generations" (really both the original design with more stuffed into the body), let's hope the service information is of better quality as well.

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