2.7T Swap into B5 Passat - ECT short+, and ALL6 Cyl's Ignition Open Circuit
#1
09-16-2014, 09:41 AM
2.7T Swap into B5 Passat - ECT short+, and ALL6 Cyl's Ignition Open Circuit
Hey guys. Looking for a little diagnostic help. Just finished swapping a 2.7t into a '00 Passat 4motion. The car runs and drives ok, but I've got the EPC light on, and some codes:
1. Engine Coolant Temp Sensor - Short to Plus
This code comes up with only the ignition on, not running. I clear the code, comes right back. I replaced the sensor, and wired in a new pigtail - still comes right back.
Is this possibly due to any differences between the 2.7t and b5 chassis? Like maybe because of differences in clusters, or maybe because of pinouts not matching where the engine harness plugs into the dash harness in the E-box? Does anyone have the wiring diagrams or pinouts for both 2.7t ('00 A6 tip) and '00 Passat 2.8L 4motion tip? Or is this likely just a glitch in wiring harness - broken or frayed wiring? Any tips or step by step to trace the issue?
2. When the ignition is on, only code is the above ECT short. When I start the car, I get 3 more: Crash Signal, EPC light circuit, and K83 light circuit. I'm wondering with these if it, too, would have anything to do with different clusters or pinouts in the E-box? I read somewhere that someone got rid of the 2 light codes by splicing in secondary LED lights and it fixed it - still need wiring diagrams or pinout to complete this. Crash Signal, I guess you cant get rid of..? Anyway, So ignition on: ECT short. Start the car: Crash Signal, 2 indicator lights. BUT When I hit the gas...................................
3. Cylinder (1,2,3,4,5,6) Ignition Circuit - Open Circuit
Why ??? First, I've heard of the ECT causing some strange issues, so would this relate to the ECT short AT ALL? Why would the car start or even run if all 6 cyl's have an open circuit? So does that mean that this is a short "blip" where all 6 cyl's lose GROUND once the throttle is tapped? Is this related to the throttle or DBW, Pedal at all? Is this a SYMPTOM of the EPC light being on - does the function of the limp mode cut signal to all 6 ignition circuits? I'm kinda lost on this one. Am hoping its either a replaceable part such as MAF, ICM, FP Relay (is there an Engine Power Control Relay that I should be looking into at all?)... Would it be as simple as running individual grounds to each coilpack and grounding to chassis?? The car will sit at Idle all day without throwing these codes, but as soon as I hit the throttle - all 6 cyl's Ignition Open Circuit...
Bought myself a new Multi-Meter, and ready for input!!! Need pinouts @ E-box, and help with step-by-step diagnostics..
Thanks in advance. Pics and build thread coming soon.
1. Engine Coolant Temp Sensor - Short to Plus
This code comes up with only the ignition on, not running. I clear the code, comes right back. I replaced the sensor, and wired in a new pigtail - still comes right back.
Is this possibly due to any differences between the 2.7t and b5 chassis? Like maybe because of differences in clusters, or maybe because of pinouts not matching where the engine harness plugs into the dash harness in the E-box? Does anyone have the wiring diagrams or pinouts for both 2.7t ('00 A6 tip) and '00 Passat 2.8L 4motion tip? Or is this likely just a glitch in wiring harness - broken or frayed wiring? Any tips or step by step to trace the issue?
2. When the ignition is on, only code is the above ECT short. When I start the car, I get 3 more: Crash Signal, EPC light circuit, and K83 light circuit. I'm wondering with these if it, too, would have anything to do with different clusters or pinouts in the E-box? I read somewhere that someone got rid of the 2 light codes by splicing in secondary LED lights and it fixed it - still need wiring diagrams or pinout to complete this. Crash Signal, I guess you cant get rid of..? Anyway, So ignition on: ECT short. Start the car: Crash Signal, 2 indicator lights. BUT When I hit the gas...................................
3. Cylinder (1,2,3,4,5,6) Ignition Circuit - Open Circuit
Why ??? First, I've heard of the ECT causing some strange issues, so would this relate to the ECT short AT ALL? Why would the car start or even run if all 6 cyl's have an open circuit? So does that mean that this is a short "blip" where all 6 cyl's lose GROUND once the throttle is tapped? Is this related to the throttle or DBW, Pedal at all? Is this a SYMPTOM of the EPC light being on - does the function of the limp mode cut signal to all 6 ignition circuits? I'm kinda lost on this one. Am hoping its either a replaceable part such as MAF, ICM, FP Relay (is there an Engine Power Control Relay that I should be looking into at all?)... Would it be as simple as running individual grounds to each coilpack and grounding to chassis?? The car will sit at Idle all day without throwing these codes, but as soon as I hit the throttle - all 6 cyl's Ignition Open Circuit...
Bought myself a new Multi-Meter, and ready for input!!! Need pinouts @ E-box, and help with step-by-step diagnostics..
Thanks in advance. Pics and build thread coming soon.
Last edited by jmayo3; 09-16-2014 at 09:44 AM. Reason: idle vs throttle
#2
09-16-2014, 10:10 AM
From another thread where swapping the 2.7t into B6:
I don't exactly understand, but maybe someone here can help to elaborate, or just tell me what to do
From what I understand and have gathered the last 12 hours of researching all these faults I have are due to the wires from the ECM not having any where to go.
"Coolant temperature signal
The engine control unit receives from the dash
panel insert a coolant temperature signal
calculated from the signal which coolant
temperature sender G2 generates and a
related temperature characteristic.
The signal is a “data message“ and is
connected to the earth potential when a
temperature of approx. 120 °C is exceeded.
In this case, the air conditioner’s operating and
display unit switches the compressor off along
the bidirectional wire designated “Airconditioner compressor On/Off“.
As of a temperature of 116 °C, the charge
pressure is reduced in order to counteract a
further rise in temperature.
If the temperature drops below a value of
approx. 116 °C, a data message is again
transferred and all actions previously
performed are reversed."
This is what I got from the 2.7t self-study. This one wire for fault 18028 which is the temperature coolant temp signal is bi-directional and gets a message from the cluster. With it not wired it it's an open circuit. Same for 18084 and 18098.
I don't exactly understand, but maybe someone here can help to elaborate, or just tell me what to do
From what I understand and have gathered the last 12 hours of researching all these faults I have are due to the wires from the ECM not having any where to go.
"Coolant temperature signal
The engine control unit receives from the dash
panel insert a coolant temperature signal
calculated from the signal which coolant
temperature sender G2 generates and a
related temperature characteristic.
The signal is a “data message“ and is
connected to the earth potential when a
temperature of approx. 120 °C is exceeded.
In this case, the air conditioner’s operating and
display unit switches the compressor off along
the bidirectional wire designated “Airconditioner compressor On/Off“.
As of a temperature of 116 °C, the charge
pressure is reduced in order to counteract a
further rise in temperature.
If the temperature drops below a value of
approx. 116 °C, a data message is again
transferred and all actions previously
performed are reversed."
This is what I got from the 2.7t self-study. This one wire for fault 18028 which is the temperature coolant temp signal is bi-directional and gets a message from the cluster. With it not wired it it's an open circuit. Same for 18084 and 18098.
#3
09-16-2014, 10:23 PM
The above post talks about 3 of the 5 codes I have:
1. 18028 ECT open to short
2. 18084 EPC warning lamp signal (k132)
3. 18098 Malfunction Indication light (K83)
Says They're all "bi-directional" meaning they send and receive signal from the cluster, and guess what I found....
5 wires where the engine harness meets the body harness. everything matches up identical except the 2.7t harness has these 5 extra wires that aren't even pinned in the 2.8Passat's body harness receiver. The locations are:
ORANGE CONNECTOR: pin#3-Red/Yel; pin#9-Brown/Red; pin#10-Blu/Red
TAN CONNECTOR: pin#5-Blk/Blu; pin#6-Wht/Blk
Are these possibly the ECT, EPC, and MIL signals that I'm NOT getting????????
But where do they go?... How do I splice them into the Passat?..
The a6 2.7t instrument cluster has an additional 3rd plug in the center that the 2.8Passat does not (it only has 2 plugs - one on each side of the cluster)....
Would I need to splice these 5 wires into that plug and swap over to the a6 instrument cluster? does anyone PLEASE have the A6 2.7T engine to body harness pinouts? How about the cluster pinouts?
1. 18028 ECT open to short
2. 18084 EPC warning lamp signal (k132)
3. 18098 Malfunction Indication light (K83)
Says They're all "bi-directional" meaning they send and receive signal from the cluster, and guess what I found....
5 wires where the engine harness meets the body harness. everything matches up identical except the 2.7t harness has these 5 extra wires that aren't even pinned in the 2.8Passat's body harness receiver. The locations are:
ORANGE CONNECTOR: pin#3-Red/Yel; pin#9-Brown/Red; pin#10-Blu/Red
TAN CONNECTOR: pin#5-Blk/Blu; pin#6-Wht/Blk
Are these possibly the ECT, EPC, and MIL signals that I'm NOT getting????????
But where do they go?... How do I splice them into the Passat?..
The a6 2.7t instrument cluster has an additional 3rd plug in the center that the 2.8Passat does not (it only has 2 plugs - one on each side of the cluster)....
Would I need to splice these 5 wires into that plug and swap over to the a6 instrument cluster? does anyone PLEASE have the A6 2.7T engine to body harness pinouts? How about the cluster pinouts?
#5
09-19-2014, 02:06 AM
Orange plug, pin#10, blu/pur - over temp warning signal
Would this cause the code for open/short to ECT?
Orange plug, pin#9, bwn/red - afterrun pump
Orange plug, pin#3, red/yel - afterrun pump
Would THESE cause the code for open/short to ECT?
Orange plug, pin#2, red/bwn - EPC warning light
I'll go ahead and assume this is the wire I need to tap into to add the LED.. anyone know how to wire it? Do I cut the wire, put a contact from LED on both sides of cut wire and run it in-line? or do I peel the insulation of the wire some, put one contact from led on wire and other contact to chassis?
Would this cause the code for open/short to ECT?
Orange plug, pin#9, bwn/red - afterrun pump
Orange plug, pin#3, red/yel - afterrun pump
Would THESE cause the code for open/short to ECT?
Orange plug, pin#2, red/bwn - EPC warning light
I'll go ahead and assume this is the wire I need to tap into to add the LED.. anyone know how to wire it? Do I cut the wire, put a contact from LED on both sides of cut wire and run it in-line? or do I peel the insulation of the wire some, put one contact from led on wire and other contact to chassis?
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