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Discussion Starter · #21 ·
The ABS warning light saga continues. I finally got back to replacing the right front wheel hub since my 2WD Rodeo has the ABS sensor integrated into the wheel hub assembly. I ended up removing the steering knuckle and taking the whole assembly to a machine shop to get the wheel hub pressed out.

Just finished putting everything back together. Brakes are working fine, but the ABS warning light is still on. The ABS light should go out after the car reaches about 10mph if the system no longer generates codes. I've only driven through the neighborhood (up to about 25mph). I tried clearing the codes by using a jumper between ports 4 and 12 on the OBD2 port. The codes are supposed to clear if you press the brake pedal six times within the first 3 seconds after the key is turned on. No luck, but maybe I didn't pump the brake pedal fast enough.

Or it could be that there are still codes being generated. When I read the codes previously, the ABS light started flashing within a few seconds of turning on the key when ports 4 and 12 were shorted on the OBD2 port. Now the ABS light just stays on - no flashing. So I don't know what codes, if any, are know being stored.
 

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Make sure the EBCM 16 pin electrical connector is properly connected. If it is loose there is a spring loaded shorting clip in the connector that will cause the ABS lamp to be continuously illuminated.
 

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Discussion Starter · #23 ·
Thank you for your quick response. Can you give me a little more detail about the EBCM 16 pin connector and what I am looking for?
 

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C-4 is the 16 pin connector that connects to the ABS electronic module that is bolted to the ABS hydraulic unit. The image shows the actual C-4 gray connector. The C-4 connector has an automatic shorting clip that connects two pins together when the connector is disconnected from the electronic module. When the two pins are connected together the ABS lamp illuminates. The red widget locks the connector to the module.
 

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Discussion Starter · #25 ·
I'll probably check the C-4 connector over the weekend. While I have it disconnected, I should be able to check the resistance of the three sensors (one on each front wheel and one on the rear axle) if I understand the system correctly. My original ABS codes indicated a bad right front wheel sensor. My manual says the resistance of the sensor should be 1.3-1.9K ohms. The old sensor had a resistance of 187K ohms, almost 100 times greater than the specification. The new sensor has a resistance of 2.4K ohms; a little high but pretty close. There should also be about the same resistance across terminals 3 and 11 of the C-4 connector if the wiring to the right front ABS sensor is not damaged. Is that right?

There are numerous posts (mostly from Buster) saying that damage to the wiring harness for the rear ABS sensor is extremely common on these vehicles. If the sensor and wiring are good, there should be about 2K ohms across terminals 12 and 4. Is that right? What are the terminals on the C-4 connector to check the resistance for the left front wheel?

Thanks,
David
 

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The Left Front ABS Sensor pins are C-4 Pins A2 and B2
The Right Front ABS Sensor pins are C-4 Pins A3 and B3
The Rear Front ABS Sensor pins are C-4 Pins A4 and B4
C-4 B2 is also pin 10
C-4 B3 is also pin 11
C-4 B2 is also pin 12
 

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Discussion Starter · #28 ·
To recap, I replaced the passenger side front wheel hub with the integrated ABS sensor based on the codes I downloaded from the ABS warning light system. However, the ABS warning light was still on after driving the vehicle with the new wheel hub. I tried to read any new codes for the ABS warning, but there were no codes. I have not checked the C4 connector as suggested since this is a low priority issue for me.

However, yesterday I tried to use my bluetooth OBD dongle to check the engine coolant and charging system with DashCommand on my iPhone. It looks like the OBD port is no longer active. This may be why I could not get any response from the ABS when I used a jumper across terminals 4 and 12 on the OBD port. Could I have shorted something and maybe blown a fuse when I was trying to get the ABS codes?
 

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To recap, I replaced the passenger side front wheel hub with the integrated ABS sensor based on the codes I downloaded from the ABS warning light system. However, the ABS warning light was still on after driving the vehicle with the new wheel hub. I tried to read any new codes for the ABS warning, but there were no codes. I have not checked the C4 connector as suggested since this is a low priority issue for me.

However, yesterday I tried to use my bluetooth OBD dongle to check the engine coolant and charging system with DashCommand on my iPhone. It looks like the OBD port is no longer active. This may be why I could not get any response from the ABS when I used a jumper across terminals 4 and 12 on the OBD port. Could I have shorted something and maybe blown a fuse when I was trying to get the ABS codes?
Pin 16 of the DLC provides +12 Vdc to power the connected scan tool or blue tooth widget. See if there is +12 Vdc between DLC Pin 16 and ground.
 
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