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Discussion Starter · #1 ·
Hi. I am working on my 2000 Honda Passport and followed this thread for reading ABS codes (my scanner wouldnt do it)


I jumped pins 4 and 12 and got my codes. I forgot the wire was in the ODB port still, and tried to start the car. Now it wont start. Do you think I fried it?

All fuses and relays tested and ok. I noticed when I turn the key on, fuel pump doesnt run. If I pull the ECU fuse, and reinstall, it runs and pumps up then shuts off.

I got a code reading once and got a P1290 (temps sensor). I also got some errors trying to scan it. I have got it to start a few times but won't idle and dies.

Any Ideas? Ive never had an ECU problem. Also, is there a specific relay on the ECU board I can replace? If I desolder and get a new relay?

Thanks
 

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The ABS Electronic Brake Control Module (EBCM) does not control the engine so leaving the ABS diagnostic enable jumper in when you attempted to start the engine is not likely the reason the engine does not keep running.

Additionally, the fuel pump does not run continuously at startup. It runs for about 3 seconds to pressurize the fuel rail when the Ignition Switch is first placed in the Run position. The fuel pump restarts when the Crankshaft Position Sensor starts to generate pulses (58x) as it rotates during engine crank and after the engine starts running on fuel.

If the engine won't keep running there may be a fuel delivery problem, monitor the fuel pressure at the test port with a fuel pressure gauge. The pressure Key On no Crank is around 40 psi and 36 engine running at idle.
 

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Discussion Starter · #4 ·
The ABS Electronic Brake Control Module (EBCM) does not control the engine so leaving the ABS diagnostic enable jumper in when you attempted to start the engine is not likely the reason the engine does not keep running.

Additionally, the fuel pump does not run continuously at startup. It runs for about 3 seconds to pressurize the fuel rail when the Ignition Switch is first placed in the Run position. The fuel pump restarts when the Crankshaft Position Sensor starts to generate pulses (58x) as it rotates during engine crank and after the engine starts running on fuel.

If the engine won't keep running there may be a fuel delivery problem, monitor the fuel pressure at the test port with a fuel pressure gauge. The pressure Key On no Crank is around 40 psi and 36 engine running at idle.

I guess it's just a weird coincidence. I checked the abs codes and am assuming a bad module. I also did ball joints which there is no way I touched anything.
 

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Discussion Starter · #5 ·
Ok 40 lbs of fuel pressure.
The things is, right after this happened I checked the ecu relay and it was hot

as well it threw some weird temp code, and is storing no codes now.

ABS codes are stored in the computer. Not the module. I think?

A used ECU is cheap and available to gonna try it.
 

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DTC P1290 is Electronic Throttle Control (ETC) System Forced Idle Mode. If the Powertrain Control Unit (PCM) detects an anomaly in the ETC the PCM can command the throttle valve to the idle position. This DTC is usually caused by a defective Throttle Position Sensor (TPS) or Accelerator Position Sensor (APS). When this DTC is set the Reduced Power lamp (RPL) is usually illuminated.

Engine and 4L30e transmission OBDII codes are stored in the PCM ("computer"), ABS codes are stored in EBCM. Most inexpensive readers/scan tools cannot retrieve the ABS codes. An Innova 3160 can.
 

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Discussion Starter · #8 · (Edited)
DTC P1290 is Electronic Throttle Control (ETC) System Forced Idle Mode. If the Powertrain Control Unit (PCM) detects an anomaly in the ETC the PCM can command the throttle valve to the idle position. This DTC is usually caused by a defective Throttle Position Sensor (TPS) or Accelerator Position Sensor (APS). When this DTC is set the Reduced Power lamp (RPL) is usually illuminated.

Engine and 4L30e transmission OBDII codes are stored in the PCM ("computer"), ABS codes are stored in EBCM. Most inexpensive readers/scan tools cannot retrieve the ABS codes. An Innova 3160 can.
thank you. I cleared the code and it hasn’t come back yet

So I guess my best course of action is to figure out to rest those two sensors.

Is there a procedure for this? Where the best source for a service manual? I’ve been doing basic stuff without a book.

I think I need to look at the testing procedures, and how to do a relearn.
 

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Btw, When the ABS electronic module detects a component failure in the system, the ABS Warning Lamp will illuminate. When the ABS fault is cleared, the ABS electronic module will turn Off the ABS Warning Lamp when vehicle speed is greater than 9 mph.

You can probably find a factory service manual on ebay or an automotive book store.
 

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Discussion Starter · #10 · (Edited)
Btw, When the ABS electronic module detects a component failure in the system, the ABS Warning Lamp will illuminate. When the ABS fault is cleared, the ABS electronic module will turn Off the ABS Warning Lamp when vehicle speed is greater than 9 mph.

You can probably find a factory service manual on ebay or an automotive book store.
Every piece of information I find here comes from you. Ha. I found some great diagrams and values to test. The only thing I am missing is expected voltage for APS sensors, pin 67, 78 and 79

I also need my gf to finish yoga so she can press the pedal and I can watch if its opening.

I may just get my transmission back in my little car while I pick away at this project. Ive been driving the passport while I rebuilt my transmission.

Edit: Found a FSM on ebay for $30 and just ordered.
 

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Discussion Starter · #11 ·
Ok I got my lovely assistant to crank on the car and press the gas and the butterfly worked fine. I had her feather it while cranking to see if voltage drop affected it and it was fine. I tested all my tps signals and it was returning two volts on blue white and three volts on blue. So this must be a bad TPS. It's getting 4.95 signal and the ground is good. It also finally threw some codes. P1125, P1295, P1120, P1220.
 

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There are two Throttle Position Sensors. The output voltage from TPS #1 (Blue) Increases as the throttle valve opens. The output voltage from TPS #2 (Blue/White) Decreases as the throttle valve opens. Each TPS is referenced from a +5Vdc source, the operating range of each sensor is approximately 0.5 to 4.95 Vdc, the measured output voltage depends upon the throttle valve position. It is expected that the sum of the TPS outputs should equal the applied reference voltage for any throttle valve position.
 

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Discussion Starter · #14 ·
There are two Throttle Position Sensors. The output voltage from TPS #1 (Blue) Increases as the throttle valve opens. The output voltage from TPS #2 (Blue/White) Decreases as the throttle valve opens. Each TPS is referenced from a +5Vdc source, the operating range of each sensor is approximately 0.5 to 4.95 Vdc, the measured output voltage depends upon the throttle valve position. It is expected that the sum of the TPS outputs should equal the applied reference voltage for any throttle valve position.
Noted. Two signal wires but one sensor unit yeah?

So I removed battery and computer to test harness. S76 Blue wire on computer has no continuity with TP1 at sensor plug
 

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There are two Throttle Position Sensors and one Throttle Position Sensor Assembly. The Throttle Position Sensor Assembly is the replaceable component.

Throttle Position Sensor (TPS) #1 signal goes to Pin 6 of the Throttle Body harness connector. The color code is Blue. It connects to Pin 76 of Red PCM connector. The Red PCM connector is closest to the fender.
 
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