Computer Question?
11-16-2002, 01:02 PM
#1
Junior Member
Thread Starter
Join Date: Nov 2002
Posts: 16
Computer Question?
How can i tell if the computer is bad??? I have no check engine light come on even if i unplug sensors etc..... the car is shutting off during acceleration... seems to happen at around 3,000 RPM (like it ran out of gas) then you can continue but gotta stay under 3,000 rpm or it does it again.. so far I've rplaced... Injectors, coils, MAFS, plugs, fuel pump... if i unplug O2 sensor makes no difference....
I think its a bad computer but how do I tell??? HELPPPPP
I think its a bad computer but how do I tell??? HELPPPPP
11-16-2002, 01:58 PM
#3
Donating Maxima.org Member
Join Date: Sep 2001
Posts: 110
ECU Check
In addition to the check engine light there is a red led on the right side of the ECU the passenger side on my 92SE. It lights the same as the check engine light. If the check engine bulb is out the led should still be on. Put the key in turn to the ON position do not start the red led should be on. The ECU is in front of the center console on the SE's accessible by removing a plastic panel on the passengr side to see the LED.
11-16-2002, 02:44 PM
#4
Junior Member
Thread Starter
Join Date: Nov 2002
Posts: 16
Re: ECU Check
Originally posted by rhard49
In addition to the check engine light there is a red led on the right side of the ECU the passenger side on my 92SE. It lights the same as the check engine light. If the check engine bulb is out the led should still be on. Put the key in turn to the ON position do not start the red led should be on. The ECU is in front of the center console on the SE's accessible by removing a plastic panel on the passengr side to see the LED.
In addition to the check engine light there is a red led on the right side of the ECU the passenger side on my 92SE. It lights the same as the check engine light. If the check engine bulb is out the led should still be on. Put the key in turn to the ON position do not start the red led should be on. The ECU is in front of the center console on the SE's accessible by removing a plastic panel on the passengr side to see the LED.
I know something is wrong because with O2 sensor unplugged still got code 55 HMMMMMMMM im stumped
11-18-2002, 07:02 AM
#8
Donating Maxima.org Member
Join Date: Sep 2001
Posts: 110
55
When it flash's 55 it has checked
11 Crank Angle Sensor
12 Air Flow Meter
13 Engine Temperature Sensor
14 Vehicle speed Sensor Circuit
21 Ignition signal circuit
31 ECU
32 EGR Function
33 Exhaust gas sensor circuit
34 Detonation Circuit
35 Exhaust gas temperature circuit
43 Throttle sensor circuit
45 Injector Leak
51 Injector Circuit
54 Signal from AT to ECU
55 No Signals from the above circuits
Mine is on all the time when the key is in the on position.
The O2 sensor probably would not show unless you did its specific test or the car reached operating temperature as it is not in the circuit till the car is fully warmed up.
But an Educated guess says you are experiencing the car going in and out of limp home mode. The fail safe so you can still drive it in the event of a problem. I'd bet the MAF is bad or the wiring harness to the MAF. A lot of rebuilt MAFs are bad out of the box.
I had a lot of success obtaning a better idle just cleaning these 3 things (Just?)
1) Thorttle Body
2) Air injection valve
3) all the connections you can get to with contact cleaner
Also saw a major improvement after cleaning the grounds on the fuel injector harness ( right behind the 2 front fuel injectors wire goes from harness to a screw.
also my MAF was never getting proper voltage, the 2 addon connectors to the positive cable were badly corroded. I chopped them off and replaced it with a brass and gold high end stereo battery post which had screw downs for 2 10 gauge wires, (Power to MAF and ECCS relay) and a Ring hold down for the starter cable. It cost me 10 bucks from Stinger.
That got everything Idling excellently for about 20 Bucks! But I still had the 2500RPM thing. In the end my MAF a rebuilt one recently replaced was bad out of the box.
The FSM & CHILTONS mention in several places the ECU is "VERY RARELY THE PROBLEM"
I bought a rebuilt maf, rebuilt by cardone from autozone. While my replacement was defective Cardone provides a 12 Month 18,000 mile warranty on all rebuilt parts ( Yes even electronics). Autozone only offered 90 days but when I called cardone and reminded them their web site quotes 12M/18Miles they called autozone and overnighted the replacement to my local store. Pretty good people!
Good Luck
11 Crank Angle Sensor
12 Air Flow Meter
13 Engine Temperature Sensor
14 Vehicle speed Sensor Circuit
21 Ignition signal circuit
31 ECU
32 EGR Function
33 Exhaust gas sensor circuit
34 Detonation Circuit
35 Exhaust gas temperature circuit
43 Throttle sensor circuit
45 Injector Leak
51 Injector Circuit
54 Signal from AT to ECU
55 No Signals from the above circuits
Mine is on all the time when the key is in the on position.
The O2 sensor probably would not show unless you did its specific test or the car reached operating temperature as it is not in the circuit till the car is fully warmed up.
But an Educated guess says you are experiencing the car going in and out of limp home mode. The fail safe so you can still drive it in the event of a problem. I'd bet the MAF is bad or the wiring harness to the MAF. A lot of rebuilt MAFs are bad out of the box.
I had a lot of success obtaning a better idle just cleaning these 3 things (Just?)
1) Thorttle Body
2) Air injection valve
3) all the connections you can get to with contact cleaner
Also saw a major improvement after cleaning the grounds on the fuel injector harness ( right behind the 2 front fuel injectors wire goes from harness to a screw.
also my MAF was never getting proper voltage, the 2 addon connectors to the positive cable were badly corroded. I chopped them off and replaced it with a brass and gold high end stereo battery post which had screw downs for 2 10 gauge wires, (Power to MAF and ECCS relay) and a Ring hold down for the starter cable. It cost me 10 bucks from Stinger.
That got everything Idling excellently for about 20 Bucks! But I still had the 2500RPM thing. In the end my MAF a rebuilt one recently replaced was bad out of the box.
The FSM & CHILTONS mention in several places the ECU is "VERY RARELY THE PROBLEM"
I bought a rebuilt maf, rebuilt by cardone from autozone. While my replacement was defective Cardone provides a 12 Month 18,000 mile warranty on all rebuilt parts ( Yes even electronics). Autozone only offered 90 days but when I called cardone and reminded them their web site quotes 12M/18Miles they called autozone and overnighted the replacement to my local store. Pretty good people!
Good Luck
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