tuning tires sized, troubles, lights come on
05-24-2005, 06:38 PM
#1
tuning tires sized, troubles, lights come on i adjusted the cars computer for the correct rear tire sizes, his front tires are smaller than the rears. his lights are comming on, the tcs, abs, and some others. is there any way to fix this? would putting the rear tire sizes in the computer do anything or help anything?
05-24-2005, 06:54 PM
#2
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I don't think the PCM will take to that too well.
I had constant TCS/ABS and Brake controller codes when I installed my 12 bolt. The cause? The wheel studs were too close to the reluctor ring pick up. If I drove over 90 the low trac light would come on.
There may be something mechanical you can adjust to make the front wheel speed match the rear...
I had constant TCS/ABS and Brake controller codes when I installed my 12 bolt. The cause? The wheel studs were too close to the reluctor ring pick up. If I drove over 90 the low trac light would come on.
There may be something mechanical you can adjust to make the front wheel speed match the rear...
05-24-2005, 07:15 PM
#4
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yes, adjusting the rear size will fix the speedometer
But the TCS, ABS, etc... lights that go on are normal... the PCM detects that the front wheels are moving at a different speed than the rear and thinks the wheels are slipping ... this is controlled in the BCM I think... not sure if ABS has its own brain box
But the TCS, ABS, etc... lights that go on are normal... the PCM detects that the front wheels are moving at a different speed than the rear and thinks the wheels are slipping ... this is controlled in the BCM I think... not sure if ABS has its own brain box
05-24-2005, 08:11 PM
#6
there isn't anyway to "trick" the computer? i'm just sick of the christmas tree dash. lol thanks mike (i think) for the help. it was crazy getting on the highway i look at the speedo and i'm doing 90, i can't believe how off the speedo was for so long i'm surprised i didn't get nailed at least a dozen times in the last year driving like that. also anyone know what size resistor makes the air bag light go out??? thanks
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05-24-2005, 08:53 PM
#8
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Originally Posted by horist
yes, adjusting the rear size will fix the speedometer
But the TCS, ABS, etc... lights that go on are normal... the PCM detects that the front wheels are moving at a different speed than the rear and thinks the wheels are slipping ... this is controlled in the BCM I think... not sure if ABS has its own brain box
But the TCS, ABS, etc... lights that go on are normal... the PCM detects that the front wheels are moving at a different speed than the rear and thinks the wheels are slipping ... this is controlled in the BCM I think... not sure if ABS has its own brain box
Electronic Brake Control Module (EBCM) - The EBCM controls the system functions and detects failures.
Brake Pressure Modulator Valve (BPMV) - The BPMV contains the hydraulic valves and pump motor that are controlled electrically by the EBCM.
During antilock braking, a series of rapid pulsations is felt in the brake pedal. These pulsations are caused by the rapid changes in position of the individual solenoid valves as the EBCM responds to wheel speed sensor inputs and attempts to prevent wheel slip.
05-25-2005, 05:31 AM
#9
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Another thing to consider, when the low trac light comes on, the PCM is pulling timing in attempt to regain "control" of the vehicle. Horrist is right, adjusting the tiresize will get the speedo right.
Not sure if a resitor trick would work. IIRC, vehicle speed is measured by counting pulses. Seems to me you would need a device to translate the actual number of pulses to the number the PCM expects.
I'll see what I can dig up for ya... sounds like a million dollar idea to me.
Not sure if a resitor trick would work. IIRC, vehicle speed is measured by counting pulses. Seems to me you would need a device to translate the actual number of pulses to the number the PCM expects.
I'll see what I can dig up for ya... sounds like a million dollar idea to me.