How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask david Your Own Question
david, Auto Service Technician
Category: Car
Satisfied Customers: 1500
Experience:  Certified Master Technician,Certified in diesel & gasoline engines
Type Your Car Question Here...
david is online now
A new question is answered every 9 seconds

I have a 1991 Plymouth Acclaim.

Customer Question

I have a 1991 Plymouth Acclaim. Could someone please tell me what the following codes mean:
and how do i fix
Submitted: 7 years ago.
Category: Car
Expert:  david replied 7 years ago.
Hi thank you for your question hope this helps.

11 = No crank reference signal detected during engine cranking
Intermittent loss of either camshaft or crankshaft position sensor

13 = No change in MAP from start to run

21 = Oxygen sensor problem, upstream or down stream

42 = Automatic shutdown relay circuit open or shorted

Fuel pump relay control circuit

No auto shutdown relay output voltage sensed by the computer

Fuel level unit - no change over miles or voltage incorrect

Hope this helps
Good luck
Customer: replied 7 years ago.
ok tell me how to fix #42 and 11 and 13 and whats fuel level unit?
Expert:  david replied 7 years ago.
Now for fixing the problems i would first start with the code 11,

When the crank sensor fails, the engine will die but no code is set. Code 11 will only set if the computer has never seen a pulse from the crankshaft rotation sensor. If the engine has been running in the past, this code will not be set because the computer remembers that the sensor was working. To check for this fault, the computer memory must be erased.



When you have a no-start condition, disconnect the battery for about 15 seconds. Reconnect and crank the engine for 7 seconds. Now pull the codes again. If you get a code 11, it means that the crank Hall Effects sensor or its associated wiring is defective. To determine whether the sensor is bad or the wiring is bad:

  1. locate the wiring harness connector closest to the distributor or crankshaft position sensor.
  2. With the ignition switch in the off position, disconnect the three-wire connector.
  3. Now turn the ignition switch back on and measure the voltage on the three wires at the computer end of the wiring harness.
    • At least one of the wires should have between 7 and 10 volts. This is the power supply wire for the Hall Effects.
    • One of the other two wires should have a voltage that is a little lower than the power supply wire. When the engine is cranked, this signal alternates between 0 and 7-10 volts as the Hall blades rotate. The alternation may be too fast for many voltmeters, but the indicated voltage will be less than the supply voltage.
    • The third wire, the one without the voltage, should have continuity to ground.
  4. Verify this with a voltmeter. Remember that the ground wire, although it will be continuous with ground, will have some resistance in it. Expect the resistance to be somewhere between 0 ohm and few hundred ohms. If the resistance reads infinity, this wire is open and must be repaired.
  5. If the wiring harness checks out good, then replace the Hall Effects sensor.

Now for the code 13 No change in MAP sensor, This could be caused by the code 11 sending the wrong info. So i would fix the code 11 then reset the computer and see it comes back.

Code 21 Oxygen sensor problem the o2 sensors are working it is selling you the exhaust is not right caused by either the code 11 or 13.

Code 42 I would check the battery cables and ground wires. If they check out ok the fuel pump may be going out
The fuel level unit is the fuel sending unit it is what runs your fuel gage
david and 2 other Car Specialists are ready to help you
Customer: replied 7 years ago.
uplugged batt. and still no cranking it was running fine and then and now nothing no crank
Expert:  david replied 7 years ago.
OK the engine is not cranking over, am I understanding you right?

What was the car doing before you pulled the codes?
Customer: replied 7 years ago.
checked again and found out that the hall plug came loose and its running fine with no codes
Expert:  david replied 7 years ago.
Happy to hear every thing worked out