88 Plymouth Sundance

loose connection on the temp sender unit, broken wire to temp sender unit
low coolant level in the system/ air lock

Generally speaking, code 12 means the battery has been disconnected at some point in time.
Code 44 means the battery temp sensor circuit is out of normal range, too high or too low.

chrysler does not use a MAF sensor on any of there engines. They use a MAP sensor (mass air pressure). What engine to you have?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Code 51 = Oxygen sensor stuck in lean mixture mode. ( this will often cause engine to run rich due to oxygen sensor telling engine controller that it is running lean, thus send more fuel) This may be caused by M.A.P. sensor as well, so check vacuum lines and clean connections on MAP sensor first. It should be one of 2 things, Fault from MAP sensor, or faulty oxygen sensor.

Sounds like two separate problems. the tapping would be your lifters ticking.

11 Timing belt skipped 1 tooth or more from initial learned value, Intermittent loss of either camshaft or crankshaft position sensor, No crank reference signal detected during engine cranking
12 Direct battery input to PCM/ECM was disconnected within the last 50 key-on cycles (normal)
13 No change in MAP from start to run
14 MAP sensor voltage too low
15 No vehicle speed sensor signal
17 Closed loop temp not reached or engine cold too long
21 02s sensor problem (oxygen sensor), upstream or down stream
22 Engine coolant temp sensor out of range
23 Intake air temp sensor out of range
24 Throttle Position sensor out of range
25 Idle air control motor circuits, target idle not reached (+/- 200),vacuum leak found
27 Injector control circuit
31 Evap purge flow monitor failure or evap solenoid circuit
32 EGR system failure
33 A/C clutch relay circuit
34 Speed control Solenoid circuits
35 Rad Fan control relay circuit
37 Torque converter clutch solenoid CKT or park/neutral switch failure
41 Generator field not switching properly
42 Fuel pump relay control ckt, Auto shutdown relay control ckt, No ASD relay output voltage at PCM, Fuel level sending unit volts out of range, Fuel level unit No change over miles
43 Multiple/ single cylinder misfire
44 Battery temp sensor volts out of range
46 Charging system voltage too low
51 Fuel system lean
52 Fuel system rich
53 Internal control failure
54 No Cam signal at PCM
55 End of error messages (If you get this only, no errors were found)
62 PCM failure SRI mile not stored
63 PCM Failure EEPROM write denied
64 Catalytic Converter Efficiency Failure
65 Power steering switch failur

It hooks up to the diagnostic port by the battery. But it sounds like you need plug wires.

Behind the dash. You will have to pull the whole dash assembly. It looks like a little radiator.

what are the codes

I have located a chilton manual CD online that I am will have in two days. Just hope it doesn't rain between now and then.