1999 Cadillac DeVille Logo
Posted on Aug 13, 2010
Answered by a Fixya Expert

Trustworthy Expert Solutions

At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.

View Our Top Experts

P1258 CODE - 1999 Cadillac DeVille

2 Answers

Greg Bernett

Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

  • Cadillac Master 2,993 Answers
  • Posted on Aug 13, 2010
Greg Bernett
Cadillac Master
Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Joined: Mar 04, 2009
Answers
2993
Questions
1
Helped
2782972
Points
13428

Trouble Code: P1258 (4.6L V8 VIN 9 Auto)
Engine Metal Over-Temperature Protection
Number of Trips to Set Code: 1
OBD II Monitor Type: CCM Details
Indicators: MIL Details

Trouble Code Conditions:
DTC P0117, P0118 and P0125 not set, Engine started; and the PCM detected the ECT sensor indicated more than 270ºF for 10 seconds. The PCM uses the ECT sensor to detect if the engine is running too hot (when the ECT sensor is over 268ºF). If the engine is overheated, DTC P1258 will set. The PCM will disable 2 groups of four cylinders by turning off the fuel injectors. By switching between the two groups of cylinders, the PCM is able to reduce the temperature of the coolant and lower the temperature.

Possible Causes:
  • Engine cooling system problem (test the cooling fan operation)
  • Engine coolant level is low or the mixture is not correct
  • ECT sensor is out-of-calibration or "skewed"

Rico Adams

Level 1:

An expert who has achieved level 1.

New Friend:

An expert that has 1 follower.

  • Contributor 2 Answers
  • Posted on Jan 18, 2019
Rico Adams
Contributor
Level 1:

An expert who has achieved level 1.

New Friend:

An expert that has 1 follower.

Joined: Jan 18, 2019
Answers
2
Questions
0
Helped
4516
Points
2

Will code p1258 make car not start

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2helpful
3answers

2006 Pontiac g6 code p1258 . The temperature gauge was fluctuating while driving from overheating to normal operation temp but no actual sign of overheating . So I replaced the coolant temp sensor ran it...

I suggest changing the cooling thermostat to make sure it's not getting stuck causing temporary overheating and flush the system and put fresh coolant in.
The guage will go hotter then go back to normal every time the thermostat opens to let cooled water into the engine block which is normal. Time for concern is when the guage goes hot and stays there along with bubbling sounds and coolant overflow onto the ground. Which you probably already know.
0helpful
1answer

P1258 code

could be a thermostat, head gasket , not fill properly,
P1258 is: engine overtemperature protection, or low coolant fuel disable
0helpful
1answer

How to fix code p1258 on cadillac

If the code P1258 comes forth on your 1998 Cadillac Eldorado, there may be three reasons:
1. Engine Coolant Temperature harness is open or shorted
2. Engine Coolant Temperature circuit has a poor electrical connection
3. Faulty Engine Coolant Temperature
Inspect all relevant connectors and he wire harness, it there are any damages, corroded, broken, or out of place components, repair if possible, otherwise replace them.
4helpful
1answer

I have a 1996 cadillac deville with codes PO741 and P1258 current. Tonight it shut down as I was driving, what could be the problem?

P0741....Torque Converter Clutch Circuit Performance or Stuck Off
P1258 Engine Coolant Overtemperature - Protection Mode Active
the first code is a generic code the latter code is a GM code and if this is correct the engine shut down because it was overheating for whatever reason or the sensor is faulty

3helpful
3answers

The other day my check engine light came on after my engine started overheating. I did a diagnostic reading on it and the code came up P1258. What does that entail?

code po 1258 is an overheating code, need to check why u r overheating, start simple, do u have fluid, has it been changed , might need thermostat, how old is truck,. is there a leak anywhere.do pressure check on radiator and see if it leaks, check radiator temperature vs engine temperature. get a thermo scanner they work good. point and it reads how hot . if motor is hotter replace thermostat. check make sure oil level is good. get back to me let me know what u find..
7helpful
2answers

Code p1258 engine light an oil light came on, 2005 equinox

2003 chev silverado truck 5.3 code p1258 the truck over heated and shut down can someone help me please
Not finding what you are looking for?

4,062 views

Ask a Question

Usually answered in minutes!

Top Cadillac Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

Sean Wright
Sean Wright

Level 3 Expert

2045 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...