The Nightmare on Oak Street: A hunt for 4L30E electrical problems
This story begins with a 4WD 1998 Honda Passport equipped with a 3.2 V6 engine and 4L30E transmission. The shift indicator in the cluster was not functioning correctly and transmission was shifting hard. The shift indicator showed ‘P’ in Park, and ‘1’ in D3, D2, or D1. The indicator didn’t light up in any other
Can of Worms (Buchse der Pandora)
A 1998 Volkswagen Jetta with a 2.0-liter engine and 01M transmission came in with a complaint of not shifting into fourth gear. The owner had just bought the car, which had the problem when he bought it, and he said it would shift normally up to third gear.
Needless to say, the history of repairs is minimal at best. What we do know is that the owner took the vehicle to a nearby transmission shop, which pulled trouble codes. DTCs for shift solenoids 6 & 4 (N93 & N91, respectively) were present, so they replaced solenoids 6 & 4 and the internal harness. The trouble codes returned immediately. That shop didn’t know what to do from there, so they referred the vehicle owner to our shop.
PT Cruiser Trouble Code Fixed with New Part
A customer brought her 2006 Chrysler PT Cruiser to our shop with a complaint of random high engine revs. She stated that restarting the engine resets the vehicle and it works again temporarily, and this had been going on for about four months. The vehicle had a 2.4-liter turbocharged engine with a 604 transmission.
Blame it on Missing Harness Retaining Clips
The subject vehicle that was fitted with one of our remanufactured transmissions six months prior showed up at one of our repair locations recently, with the customer concern of an intermittent bumpy 1-2 shift, and a low-power lugging sensation along with a CEL on. While performing our initial evaluation, we found a P1860 code stored in history, but not current. During the road test the truck was working well with no clear signs of what set the DTC, but after several minutes of driving it started to act up. The TCC was applying right on top of the 1-2 shift, but according to the scan-tool data, was not being commanded on by the ECU.
Sensor signal? Nearly none, but unit still worked
The customer had multiple concerns: 30-40 mph is the top speed, drive modes won’t switch, neutrals out in reverse, stuck in low gear at times, can’t shift manually, only works in drive Stored DTC 2767, Component Y3/6n3 (speed sensor) is faulty.
Misinformation forces tech to work harder
As with most of the accounts we’ve shared detailing vehicle symptoms and repairs, electrical issues seem to be the most common root cause. Our subject today involves a 2003 Dodge Sprinter 2500 that showed up at our door with the customer informing us that they could not shut it off since it would not restart without jumping the solenoid on the starter. The gentleman stated it would not start with the key, the shifter would not come out of park and the transmission would not shift. He also stated that we had installed a TCM about a year ago, and because it did not shift, the customer thought it was related to what we had done. He also stated he had replaced the fuse in the fuse panel for the transmission and that didn’t help. Apparently, we needed to diagnose some electrical problems.
We’ve all had to chase intermittent vehicle issues. What makes them so challenging is that you can’t fix what you can’t see. Sure enough, it always seems that the concern disappears when you’re trying to diagnose the issue in your bay.
This story is a similar case. We were diagnosing a 2002 Dodge Grand Caravan with a 604 transmission and 3.8L engine. Six months prior, the vehicle owner contacted us and said that the transmission would not shift and was starting off in 2nd gear. By the symptom description, the unit was likely going into failsafe mode. We scheduled an appointment, but the customer was a no-show.
Sometimes I Wonder, ‘What Were They thinking?’
Case in point is a 1992 Ford Bronco (Figure 1) with a 5.8-liter engine and E4OD transmission. The vehicle came to our shop with shifting issues. The owner said he was driving along and all of a sudden it shifted down and then slammed back into gear, and then a short time later it shifted down again but this time would not upshift. He thought it was stuck in low, although it did not act up on the way to our shop that morning. The owner had recently bought this vehicle with some known issues. There was a rear-ABS lamp on and the Check Engine lamp was not on.
‘Why should I pay for diagnosis?’
A 2003 Lincoln LS with a 3.9-liter V-8 and 5R55S transmission came into our shop with a grocery list of codes stored, no power, and it didn’t shift. I scanned for codes, found P0715, 717, 718, 731, 732, 733, 734, 745 and P2106. As you can see it had turbine-speed-sensor codes, gear-ratio codes, pressure-control fault and a forced limited power from the TAC. My first thought was that the turbine-speed sensor had failed and as a result of continued driving set the other codes.
Verify the Systems Before Condemning the Transmission
A few months ago a customer brought in a 2003 Dodge 1500 pickup with a 5.7 Hemi engine and 545RFE transmission. The Check Engine lamp was on and the truck would not accelerate from a stop unless you put the transmission in second gear.
Don’t Blow Your Fuse
The vehicle involved was a 1998 Honda Passport 4WD with a 3.2-liter V-6 and 4L30-E transmission. The shift indicator in the cluster was not functioning properly, and the transmission was shifting hard. The indicator showed P in Park and 1 in D3, D2 and D1, and it didn’t light up any other time. This seemed to be pretty straightforward, since the mode switch (range sensor) has a high failure rate.